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ric 30 May 2018, 23:22

Here i just can find swimming googles up to -10. Is the best help i could get.

Likelenses 30 May 2018, 22:05

More of her.

30calcat 30 May 2018, 19:10

I believe this lady was well into the minus mid teens and had to get very thick lenses custom bonded into her diving mask:

High Myopic 30 May 2018, 14:59

You guys have seen a scuba mask with minus prescription lenses stronger that this? They are over -10 diopters!

Front View.

View 2.

I would love to find a -15 or even a -20 diopter pair!!

Glass Lenses 13 May 2018, 00:53

If you want REAL glasses.

30calcat 09 May 2018, 06:26

I purchased the glasses online a while back but got the lenses updated this week at Walmart vision center.

 08 May 2018, 14:16

Cherryl would have to be real first though, right? That might be your biggest obstacle. hahaha

james 08 May 2018, 11:31


Where did you get the glasses from?

minus5wholuvsgwgs 08 May 2018, 08:05

Calcat they do look good what RX are they

Likelenses 08 May 2018, 00:07


You will be the hottest babe on the beach with those beauties.

I may see if I can get Cheryl a pair like those.

30calcat 07 May 2018, 23:28

Got the lenses on my sports wrap frames and they came back very thick:

The lens curve runs all the way up to 15mm where it runs out lens blank on the very edge. They are very heavy, but with the strap attached they are very comfortable and secure. The thick frames hide the lens thickness on the sides but they still look like as thick as bulletproof glass. The lenses are so thick that they rub against my face, so they might get foggy and dirty quickly during sweaty activity. But they will be perfect for swimming, and I can't wait to be able to see clearly in the pool.

Double 8 05 May 2018, 10:07

Can you post of a picture of the phoropter that you own? I am curious how you set it up with the bracket.

Likelenses 04 May 2018, 22:31

With the rainy weather that we have had Cheryl, and I have been indoors quite a bit.

We were going through some of her old family photos, some of which showed her at fourteen years old sporting her first glasses. They were the 1970's wire rim gold hexagons.

She mentioned that the doctor had told her that they were rest glasses, because her eyes were very strained. That led her to think that after a while of wearing them, that her eyes would go back to normal.

She was always self conscious about her glasses, and shortly after getting them felt uncomfortable without them. Within a year she had two increases that brought her up to minus two fifty. She talked about a boyfriend that she really cared for, and how when they were out together he would take her glasses, and tell her that she really did not need them, and that he liked her better without them. She said that she had to squint to see, and that she thought that maybe her boyfriend was right, and that by wearing her glasses for other than just to rest her eyes was why she was not able to see well

A while back her mother gave her a box containing her complete vision history, and all of her old glasses to include those old Hexies. We looked up the Rx, and they are minus one for each eye. She put them on, and of course they made no improvement to her now double digit eyes. She did look very sexy in them though.

She modeled many of those oldies, as we walked down the memory lane of her ever increasing myopia.

She still feels self conscious,but now not so much about her glasses, or their strength, but more of an inferior nature due to poor vision. When at an eye exam., she feels embarrassed about not being able to see the eye chart,without glasses and now with her present Rx not able to read the 20/20, or 20/25 lines due to minification.

Glass Lenses 19 Apr 2018, 22:59


Those myo lenses would make great desk top paper weights for OO people .

Owlish 18 Apr 2018, 21:10

For those interested in myodisc lenses some with unusually tiny bowls are shown here:

unfortunately they aren't set in frames.

I, Glasses 30 Mar 2018, 14:40

Assuming the use of CR-39 plastic, which of these will result in thicker lenses -- maximum center thickness or safety lenses?

Paul 28 Mar 2018, 17:08

I just ordered a semi-rimless pair from Firmoo in my prescription of -7.75, in their standard 1.5 index. I do have a glasses fetish but I'm pretty new to this site. Will these glasses be hideously thick? I am looking to expos thickness but not to the point of ice cubes.

Brett 27 Mar 2018, 11:09

This is similar to what Likelenses put up on 12 March, but a little more detailed.

Likelenses 24 Mar 2018, 21:53

I purchased a phoropter on ebay, and it arrived today.

I fabricated a bracket so that it can be used from a small table.

Cheryl, and I spent the day playing around with it, and refracted each other several times.

Then Cheryl wanted to watch TV through it. She found that she liked viewing the TV best with a 1.25 over correction.

hyperaficionado 15 Mar 2018, 07:44

@jay: here they say from +6.5dpt until +20dpt



Jay  15 Mar 2018, 07:11

Can anyone tell me what strength omega lenticular lenses ( for + vision ) star at ?

Likelenses 12 Mar 2018, 23:05

This is pretty cool.

Likelenses 12 Mar 2018, 22:53

How about these babies ?

Lou 11 Feb 2018, 11:54

Hi Weirdeyes

Thanks very much for the clarification.

Take care


High Myopic 11 Feb 2018, 07:21

Glass Lenses You can email me at Then you will not get weird replys.

Glass Lenses 10 Feb 2018, 23:57

High Myopic

Right after posting my email address to you at this sight, I received some very bizarre, and sick emails,

I am not blaming you for them, but because of them I closed that email account,

Sorry, but as a woman, I do not need to be spoken to like that.



High Myopic 10 Feb 2018, 17:13

Glass Lenses, I still could not send you a email. Your email address that you showed me did not work. Can you confirm that?

Glass Lenses 10 Feb 2018, 16:59


So now the fiddling has jumped over to this thread.

High Myopic 10 Feb 2018, 12:37

Have you guys ever seen a pair of glasses like these?

Back view.

Close up.

Very close up.

Weirdeyes 10 Feb 2018, 12:12


I kind of do like that frame. It just doesn’t fit my face the best. With that frame I even noticed some facial distortion with my +1.25 right eye. I also don’t like that it’s a clear frame. I still love the way clear frames look with minus or plano, but high plus and clear frames just don’t mix well. I still gravitate towards clear frames, but every time I do I remind myself high plus and clear frames don’t mix! I guess I’ll have to embrace the coke bottle look for a while. The OO in me kind of likes it. I just don’t like asymmetrical lenses. It kind of takes the fun out of things. If both my eyes were like my left eye I’d probably order some glasses in CR39 when I want to wear thick glasses. I currently get my glasses and contacts at Costco. Which is a discount place, but I get the advantage of having a relationship with them. I think they’re willing to change the lenses in both my glasses for free if I get a new prescription next month. That’s the perk of being a regular customer.

Lou 10 Feb 2018, 09:54

Hi Weirdeyes

When you mention your most recent pair of glasses, I'm presuming that you mean your most recent distance pair with the +0.75 Sph -0.75 Cyl right eye prescription, and that since your new prescription is for reading and you are not sure whether you will eventually be able to wear it for all distances and hence need to keep your existing distance prescription for now, that you have had to have an old frame re-glazed with your new reading prescription.

I'm not sure about the cost of frames in Canada, but they are very variable in the UK. Specsavers are generally quite a bit cheaper than the other chains.

Personally I wouldn't pay for presumably fairly expensive lenses (or are they covered by insurance?) in a frame I didn't really like, but I fully understand about having to keep the cost down.

I have no idea whether this frame would exaggerate the strength of a prescription above +5.00 too greatly, but since you don't know if/when you will need a stronger prescription than +5.00, I'd try not to worry about it.

It may very well be the case that your distance vision clears with your reading prescription, that you return to one prescription, and you end up with your most recent frame which you like, spare for future re-glazing, since it contains a distance prescription which is no longer sufficiently strong.

Building up a good relationship with your opticians sounds a good idea.

Take care


Weirdeyes 10 Feb 2018, 09:28


Because the frame is a bit decentered and wide, it actually looked stronger than my other glasses. My most recent pair is very centered, so it looks quite a bit weaker. I’m not too crazy about using that frame for that reason, but I had to save money. I know I’ll also have to use that frame if my reading prescription increases. That frame might be okay with +5.00, but would it be okay with anything much stronger? I actually bought it on clearly contacts, so I couldn’t try it on. The frame is decent quality, so the optical place had no problems using it. It helps that I’ve nearly used that place for ten years. So they know me.

Lou 10 Feb 2018, 03:08

Hi Weirdeyes, since you've gone for aspheric lenses in a higher index, especially in the same frame, I don't think that anyone will notice the stronger prescription. Possibly the reduced magnification of the aspheric lenses could make the prescription look weaker. I don't know, as I have can't see both lenses to compare.

Trying your new prescription full-time seems a good idea, but and I'm sure you know this already, you really must make sure that you wear just the one prescription, put your glasses on the minute you wake until you go to bed (obviously you are not going to wear your glasses in the shower), so that you eyes are relaxed as much as possible, and do this for at least a month.

All the best


Weirdeyes 10 Feb 2018, 02:11

I’m getting my previous glasses frame reglazed with my “reading” prescription. I wonder if it will look noticeably stronger to other people. The old prescription was R +1.25 -0.75 L +4.00 -1.25 in 1.61 and not aspheric. The new prescription will be R +1.50 -0.75 L +5.00 -1.25 in 1.67 aspheric. I’m planning on trying this prescription full time to see if I adjust to it for distance since my current distance prescription gives me terrible eye strain. I’m willing to put up with a bit of distance blur for a bit if a lot of my eye strain goes away.

High Myopic 08 Feb 2018, 18:22

What diopter do you think the right lens loupe is on this pair of glasses? The loupe looks like it is in a plus carrier in the right lens.

Lou 30 Jan 2018, 05:58


You are very welcome. I'm very glad to hear that my post has been of some help.

Best wishes


CH 29 Jan 2018, 19:20

Thanks a lot for the answers. Lou, I think you are right and I should just get the glasses without caring too much about what other people might, or might not, think about them. Your post has made me a lot more confident about this, so thank you!


Lou 29 Jan 2018, 05:31

I've been thinking about CH's post and the idea that glasses need to look sufficiently strong that they are not mistaken for plano glasses worn for fashion. It seems to be the idea behind a lot of the posters on the induced myopia thread (I have no interest in this topic, but occasionally read other threads when browsing on my phone when waiting to pink the kids up), who want to increase their prescriptions so that their lenses look stronger.

Is this a new phenomena, caused by glasses becoming fashionable and some people wearing them as an accessory?

If it is the case, I think that it is a real shame that young people are trying to increase their refractive error so that their glasses look stronger, and are not mistaken for a fashion accessory.

I have a few pairs of glasses, and like to wear different ones to match different outfits etc. This probably goes hand in hand with the fashion of people wearing glasses as accessories, but I don't see anything wrong with this. We wear shoes to protect our feet, but we still like to wear different ones for different purposes/to match different outfits.

I am the only person I know in the circles I mix in, who seems to switch between a few pairs of glasses. Combined with my prescription also being small, this could make people more likely to think that my glasses are a fashion accessory, but I doubt it, and even if they do, they can think what they like and ask me if they want.

Not one person has ever asked me why I have more than one pair of glasses, and since one pair are bright red, I imagine that they have noticed.

I wear my glasses because I don't like burning uncomfortable eyes, and glasses which don't work so well for me when worn intermittently, as my eyes get so strained without that they don't easily relax when I put on my glasses later in the day. I've learned that for me, wearing a very small prescription full-time prevents eye strain and gives good consistent clear vision throughout the day and into the evening. If the flip side, is someone thinks I wear glasses for fashion, so be it.

All the best


Lou 29 Jan 2018, 03:56


I wear the following prescription full-time, owing to severe eye strain:

R: +0.50 Sph -0.50 Cyl Axis 92

L: +0.25 Sph -0.25 Cyl Axis 85

If I take my glasses off and hold them in front of me, you can see that both lenses are prescription, more so naturally my right lens, but you can see that the left lens is not plano.

I'm not sure what the lenses really look like to others when I'm wearing them, but I strongly believe that it ultimately does not matter.

Nobody has ever mentioned my very small prescription, except my sister who tried them on and commented that they are such a small prescription, they make no difference, so why do I bother wearing them. Since she comments equally about everything, I didn't take any notice of her, and said that the prescription is probably wrong for her eyes, and that if it was correct she would notice the improvement.

In fact the very very few people who have mentioned my eyes over the years, have presumed that my eyesight is a lot worse than it is. Four people have mentioned my glasses in eight years of wearing them, one asked me if I was long or short sighted since her husband had just started wearing glasses, another joked when I remarked that a piece of band music (I'm a musician) was rather small, that that was what the things on the end of my nose are for, one asked me if I was wearing contact lenses or could see without my glasses on the one occasion I didn't wear them to an orchestral rehearsal, as they had never seen me without glasses, and the last one when I was having a chat with a fellow mum about her daughter's glasses (the mum initiated the conversation not me). Her daughter had been born very prematurely and had had her natural lenses removed and replaced with implants as a baby owing to cataracts. She wears bifocal glasses and has lots of eye appointments. I asked whether the little girl had normal vision, and the mum said as well as anyone else who wears glasses, I don't know what you can see without your glasses.

I therefore have a feeling that most people don't notice the lenses of people's glasses and simply presume that you need them to see.

I hope that this will help.

I'd get the glasses if you notice the difference. They are your eyes and it is your choice. If anyone does comment on the small prescription, you can just say that they stop eye strain and headaches, whether this is the case or not. Nobody wants headaches, and this sounds a perfectly reasonable explanation even if you aren't really getting headaches.

Best wishes


Billy A 29 Jan 2018, 03:00

Glasses with this RX will look like plano (fake) glasses...

Likelenses 29 Jan 2018, 00:57


You could bump the sphere part up by -.50 for each eye, and order the glasses online.

Leave the cyl part of the prescription as it is .

The glasses will look like a normal prescription, and you will have the benefit of super sharp, high definition vision.

CH 28 Jan 2018, 18:20

Hey there,

I recently had an eye exam because I felt that my left eye was weaker than my right one. My prescription turned out to be: L Sph -0.25 Cyl -0.25 and R Sph 0.00 Cyl -0.25 (I don't know the Axis values right now but I can look them up if it is important).

As there definitely was some noticeable improvement even in my right eye, I do consider ordering glasses.

However I have one question: Will the power of the lenses be visible to other people? The reason I ask is that I wouldn't like everyone around me to think I'm wearing non-prescription glasses for fashion reasons or whatever. I wonder if especially the Sph 0.00 Cyl -0.25 lens would look like it didn't have any optical power at all when I wear the glasses.

Your help would be greatly appreciated,


High Myopic 23 Jan 2018, 13:08

What do you think is the Rx of these glasses.

Lip 22 Jan 2018, 18:24

Cactus Jack

Thank you !

Cactus Jack 22 Jan 2018, 12:30

Oops, last post was from me, intended for Lip.


 22 Jan 2018, 12:11



R Sp +0.25 Cyl -0.25 Axis 80 Prism 5 BI

L Sp +0.50 Cyl -0.50 Axis 102 Prism 5 BI

PD 66

BI Prism will cause the inside edge of the lenses to be thicker. It will cause your eyes to turn outward about 3 angular degrees for distance.

If you want glasses for close work, with the +2.50 add incorporated in the Sphere, try.

R Sp +2.75 Cyl -0.25 Axis 80 Prism 5 BI

L Sp +3.00 Cyl -0.50 Axis 102 Prism 5 BI

PD 63

The lens maker should adjust the PD for the Prism

Note: I added the - sign for the Left Eye Cylinder.

No guarantees about comfort under all conditions. I suggest ordering the lowest cost frames and lenses with minimal options. Only consider the low cost A/R coating.


Lip 22 Jan 2018, 07:56

Cactus Jack

I posted a request(under Lenses) on 17 January for some help with Prism glasses, wondered if you could please help?

Lip (Leo in Perth.

Lou 22 Jan 2018, 02:50

Hi Weirdeyes

All sounds pretty possible and reasonable.

Take care


Weirdeyes 21 Jan 2018, 10:48


I’m pretty sure my right eye sees 20/30 without correction. Not terrible, but not too sharp. Since the axis is a bit wrong and I could still see 20/20 maybe I can see 20/15 with the correct axis. I’ve been told my left eye can see 20/20 by a few optometrists. I think the drops made my left eye need a bit more plus which made me not see 20/20 at the time. It just looked too high contrast to see properly which is a sign of too much minus or not enough plus. When my eyes are very strained my left eye sees a bit more sharply. Maybe I have a BCVA of R 20/15 L 20/20 which could confuse things. Visual acuity testing isn’t as precise as people think anyways.

Lou 21 Jan 2018, 06:03

Hi Weirdeyes

I fully understand. I have 6/6, equivalent to 20/20, vision in both eyes, but how my optician explained it, is that 6/6 is considered minimum normal human vision, and for some people 6/6 is their best correctable vision, but many people can be corrected to 6/5, and some 6/4. She said that if your eyes are capable of being corrected to greater than 6/6 but you are only seeing 6/6 owing to a refractive error, the refractive error can cause eye strain, owing to your eyes trying to correct the refractive error. She said that small amounts of astigmatism commonly cause eye strain in patients who have 6/6 vision and are capable of seeing 6/5 or even 6/4 with their astigmatism corrected. This is the case with me. I have 6/6 uncorrected vision in both eyes, which can be corrected to 6/5 + 1 in both eyes with glasses.

It sounds like your vision in your right eye is along the same lines as both my eyes.

Thanks very much for the clarification regarding the accommodation tests.

I'm not sure of the general view regarding cycloplegic exams on adults. I've never had or been offered one.

Regarding doing your job, I think that you need an optometrist rather than an ophthalmologist, and I'm not sure that there is any particular indication that you really need a dilated exam, just a good thorough exam from someone who is willing to discuss your changes in prescription and work with you to find a good accurate prescription that works well for you on a daily basis. Personally I would not wear you contact lenses for 24 hours of so before the exam, in case they are temporarily effecting your prescription for a period after removing them.

I'm not surprised you are concerned regarding he accuracy of your eye prescription, as you seem to be getting a lot of variation.

Best wishes


Weirdeyes 21 Jan 2018, 04:49


I guess they thought I didn’t need glasses because I could see 20/20 with glasses on with my right eye and my autorefractor reading was low. They think I can get by without glasses because of how perfect my right eye is. I guess I can, but I don’t care for double vision or terrible depth perception. I did some rough accommodation tests by measuring how close I can focus with my distance rx. Based on charts it seems like I’m on the upper end of end of normal for my age. This is assuming I have no latent hyperopia. What I mean by being grouped with 30 year olds is that some people think it’s pointless to do cycloplegic exams on adults. They consider me an adult. I wouldn’t have to do self-diagnosing if people did their job. I have a fairly simple overbite no one ever really has trouble dealing with, so I never self-diagnose issues with my teeth. If my eyes were that simple I’d probably have a bit of interest, but no OCD obsessions about my eyes.

Billy A. 21 Jan 2018, 03:10

Such a beautiful lenses, very interesting and unbelievable. Who the hell needs -21 cyl?? I'm wondering, how the eyes must look like behind this lenses. Any ideas?

Lou 21 Jan 2018, 02:49

Hi Weirdeyes

I fully understand what you are saying, and it should be perfectly possible to find an eye care professional who cares. I think that you should ask around friends and family for recommendations of a good optician, who seems genuinely interested in doing their best to help their patients.

I agree that your glasses prescription is complicated.

I think that your left eye values and big difference between your eyes mean that you do need glasses, but I'm not an eye care professional.

Sorry, I have no idea how well tropicamide is supposed to work, never having had a dilated exam.

Also, I'm sorry but I have no idea about your accommodating ability and how it compares to most 21 years old. I'm 44 and still have enough accommodation to have to wear a very small prescription full-time, otherwise I get bad eye strain accommodating over it, and my eyes find it hard to fully relax when I put my glasses on for the first time later in the day. It could maybe be argued that if I was younger my eyes could maybe relax their accommodation quicker when I first put on my glasses, but that I still don't need a reading add at 44, suggests to me that I still have a reasonable amount of accommodation left.

I think one problem, without meaning any offence at all, is that you do a lot of self diagnosing. How do you know that your ability to accommodate is more similar to a ten year old than an adult? I'm not being rude or unkind and obviously do care, considering the amount I've written trying to help you, I'm just querying whether you have the evidence to back this idea up, or whether it is just your presumption because you can still focus quite well with dilation drops. My intention is to try to help you to evaluate your thoughts, and separate those you know to be the true from ones that are presumptions and guesses.

I wouldn't have thought that an eye care professional would group a 21 year old with 30 year olds. Why would they, as it makes no sense?

Take care


Weirdeyes 20 Jan 2018, 13:41


I notice a lot of people value efficiency over accuracy. They just don’t care. I want to find someone that does. It really sucks to have OCD and a complicated glasses prescription. You really can’t tell what’s what. A lot of people don’t even agree on whether I need glasses or not. They think tropicamide is good enough for me. I could still accommodate pretty well with it! Like a lot. I could still read my phone screen if I help it arm’s length. The “problem” I have is that my ability to accommodate seems more similar to a ten year old than an adult. I’m only 21 anyways. They seem to be grouping me with 30 year olds.

Lou 20 Jan 2018, 13:29

Hi Weirdeyes

Thanks very much for the further clarification.

I still think that an accurate prescription needs to be found for you, as they vary too much in my opinion.

I would be interested in other people's opinions of how best for you to proceed.

All the best


Weirdeyes 20 Jan 2018, 12:34


I’m currently wearing R +0.75 -0.75 L +4.25 -1.50. The interesting thing is that the autorefractor readings in the left eye dropped to +4.50 -1.50 when I went without the +3.25 contact lens. So my left eye seems to accommodate a lot without correction. Which might explain why my first prescription is R 0.00 L +1.25.

Lou 20 Jan 2018, 12:11

Hi Weirdeyes

Thanks very much. I meant your recent autorefractor reading along with the prescription you are currently wearing, which was unchanged at your eye test before your ophthalmologist appointment.

However what you are posting is very interesting. If I understand correctly, with a +3.25 contact lens in your left eye, the autorefractor result from several years ago was equivalent to the following without glasses/contacts:

R +2.25 -0.75

L +5.50 -1.50

This is very different to your recent reading without glasses/contacts, which when converted to minus cylinder form is:

R +0.50 -0.25

L +3.50 -0.75

I think that these different readings plus your right eye glasses prescription values also continuing to decrease, are reason alone for an optician to be happy to see you to help to explain what is going on.

I wouldn't keep putting this down to anxiety. You are receiving very different results in the period of only a few years, and this needs looking into.

Good luck with getting this sorted.

Best wishes


Weirdeyes  20 Jan 2018, 10:16

Here are my autorefractor results I got several years ago. With a +3.25 contact lens in my left eye I got.

R +2.25 -0.75

L +2.25 -1.50

My recent reading without glasses was

R +0.25 +0.25

L +2.75 +0.75

I know for sure my astigmatism is pretty much the same.

Weirdeyes 20 Jan 2018, 10:08


I have heard autorefractors vary a lot on cyl. I think this one overminuses and undercyls. I definitely see better with -0.75 cyl. Without it a lot of text is unreadable. I could read the 20/20 line with it and the doctor assumed my right eye naturally has 20/20 vision naturally because of the low autorefractor reading. But I know I definitely can’t see the 20/20 line without correction.

Lou 20 Jan 2018, 05:21

Hi Weirdeyes

Obviously I can't be sure of the reason for your eye strain.

If I was in your situation, I would be concerned that the autorefractor at your last eye test gave a prescription that differed quite a lot from your last eye test. I fully understand that the autorefractor is just a starting point, but the cylinder values in particular, were significantly different in my opinion. Now I don't personally know much about autorefractors, having only looked into one the first time I went to my current Opticians (Specsavers) in around 2010. My last two eye tests have been by one of the directors. I was booked into see her originally because I was having some slightly non standard issues, and I requested her the second time. Anyway I digress. Going back to autorefractors, I wouldn't have thought that one would have given such a different prescription to your last prescribed one.

I'd be interested in other people's opinions in whether your last autorefractor and eye tests results are too different. Would you therefore mind please re-posting the two prescriptions one after the other, for this purpose, thank you very much.

Yes, I agree with not wearing extra plus. I feel that a lasik consult should finally get you an accurate prescription, but feel that you shouldn't have to go to this extent, unless you are definitely considering lasik to get rid of your glasses/contacts.

In your situation, I'd take your previous prescriptions and the autorefractor results to a recommended optician, and ask them to please determine your accurate eye prescription, as you have become very worried that you may be wearing the wrong prescription. I think that any reasonable eye care professional could understand someone being worried by differing prescriptions, and a patient's desire to have an accurate prescription.

Good luck at finding a solution to this.

Best wishes


Weirdeyes 19 Jan 2018, 22:46

I’m trying out just wearing contacts and not wearing extra plus. I feel like I’m getting eye strain now. Don’t know if it’s OCD, not being used to my rx or latent hyperopia. Hopefully a lasik consult can solve this. While image size difference does seem to be a factor I don’t think it’s the easy explanation a lot of people immediately go to. Just like latent hyperopia might not be the easy explanation I’m looking for. I’ll mention eye strain at the lasik consultation.

Weirdeyes  19 Jan 2018, 20:42


Nice to know I’m not the only one with fluctuations in best corrected vision. Sometimes my left eye is actually clearer than my right eye. Maybe that test was weirdly done. I’ll just call my left eye borderline amblyopic. Even if it can be corrected to 20/20 my brain will still favor my right eye. I’ll be sure to research it. I’m just going for a consult. I’m also hoping for more through eye tests which will help me out even if I don’t get LASIK. Just trying to calm down my OCD.

Lou 19 Jan 2018, 16:46

Hi Weirdeyes

Sounds a reasonable way to proceed.

Take care


Weirdeyes 19 Jan 2018, 15:52

For now I think the eyestrain is due to image size differences and anxiety. I’ll just make a lasik consult and trust they can find any latent hyperopia. I’m pretty sure I do have it, but it might be mild. Maybe I’ll wear glasses when I’m older, they’ll just have a more similar prescription.

Lou 19 Jan 2018, 13:58

Hi Weirdeyes

That you were still able to accommodate a bit with the drops, does suggest that the drops were not fully effective, but rather than them being weak, it could be owing to your eyes having been straining for so long, that they cannot easily relax

That he didn't refract you, doesn't seem very helpful, especially since the reason for your appointment was I thought to check the accuracy of your current prescription, and the reason for your eye strain and near vision issues. If you don't mind me asking, what questions did you ask him, and did he give you a satisfactory explanation for your eye strain and near vision difficulties?

Regarding getting a consultation for lasik, I'm not sure even if this would fully uncover all latent hyperopia, as I believe that it if has occurred over a long period of time, that the dilation agents may only be strong enough to uncover a proportion of it, and it may be a case of prescribing a little more plus than the patient can clearly see in the distance with, wearing the prescription every waking moment for several weeks, maybe even months, until the distance vision fully clears, prescribing a little more plus and so on, until the the point is reached when the eyes cannot tolerate any more plus, and the distance vision no longer clears.

Obviously I'm not sure whether lasik is the best option for you, but you shouldn't need to have a consultation for lasik to get an accurate prescription. Any good optician, should understand your concerns that your prescription could be too weak owing to eye strain even in the distance, and near vision difficulties in a patient who is only 21 years old and has good accommodation.

Maybe if you avoid using any other technical terms, and don't appear to have researched the subject at all, you could mention latent hyperopia (maybe telling a little white lie, and saying that a friend suggested it to you when you talked to her about your difficulties, as your symptoms sound similar to those her brother previously had, and in his case it turned out to be latent hyperopia), and ask whether they think that it is a likely possibility in your case.

I do believe that your eyes are causing you anxiety, and hopefully getting your eyes sorted, will relieve your overall anxiety.

Best wishes


NNVisitor 19 Jan 2018, 13:20


You tried your best. The ophthalmologist tested your vision.

I don't know why you saw less than 20/20 in your left eye. While your situation is different than mine I have experienced variences in my best vision at dofferent eye examinations.

You can inquire about Lasik. Learn everything you can about it beforehand. It does permanently change the cornea. This is something to consider as well.

How does your mother feel about how things went at the exam? Have you discussed Lasik with her?

Hopefully you just relax for now as you've tried and the results are what they are.

Weirdeyes  19 Jan 2018, 12:38


I could still accommodate with the drops in a bit. They put the drops in after the autorefractor. They never refracted me. They just tested my acuity with glasses. I don’t know why my left eye got blurrier. It could be all sorts of reasons. Maybe this is my anxiety talking, but I’m thinking of getting a consultation for lasik. If I truly have latent hyperopia they’ll find it. If I don’t I can just get lasik on my left eye and never think about my eyes again. At least until I’m in my 40s. I’ll also consult with mental health people. Maybe lasik will improve my mental health or maybe it won’t.

Lou 19 Jan 2018, 02:37

Hi Weirdeyes

Sorry for the delay in replying to you, I had rather a busy evening.

Re.: Lou

It went horribly. He was a nice doctor, but didn’t know shit about refractive error like I expected. The autorefractor also sucked. It said I’m R +0.25 +0.25 L +2.75 +0.75. They also used weak dilating drops that never totally relaxed my eyes. My mom had a lot of faith in him just because he’s an ophthalmologist. Since they tested my corrected acuity as my drops were starting to work my left eye couldn’t see the 20/20 line. I know it got 20/20 before. The drops definitely blurred my left eye more than my right eye.

I'm really sorry to hear this. To try to understand better what happened, do you mind if I ask you a few questions. When you were tested by the autorefractor, was this before or after the dilation drops, or both?

You mention the dilating drops being weak and not fully relaxing your eyes. Please don't take this the wrong way, but did the Ophthalmologist say that the drops were weak, if not how can you be sure that they were, and how do you know that they never totally relaxed your eyes? Is this because you were still able to accommodate well after your eyes were dilated? Did the drops blur your left eye more than your right simply because your left eye has more refractive error? I think that there are three possibilities, that you have no latent hyperopia to uncover, that your eyes are so strained that even if the drops were sufficiently strong for most people, they didn't work very well for you, or that the drops were too weak.

When you say that they tested your corrected acuity as the drops were starting to work and this resulted in your left eye not being able to see the 20/20 line, sorry I'm not sure what you mean. Surely if the drops were starting to work, it would be a case of finding your refractive error with your eyes in a semi-dilated state. I'm not sure why the ophthalmologist checked your visual acuity when the drops were starting to work. I would have thought that he would have done a refraction before and after to see whether the drops uncovered any latent hyperopia. Whatever, surely it would have been possible to correct your left eye to 20/20, since it has been corrected to 20/20 before. If you are saying that after dilation, your left eye could not see 20/20 with the prescription determined by the autorefractor before dilation, wouldn't this be the very thing the ophthalmologist is looking for, evidence that in its dilated state, the eye needs a stronger prescription. However since I don't know all the details, I'm just guessing.

Did he give you an actual prescription, or just autorefractor readings?

Converting the autorefractor reading to minus cylinder, they are:

R: +0.50 Sph -0.25 Cyl

L: +3.50 Sph -0.75 Cyl

I fully appreciate that you are more than capable of doing this for yourself.

These are clearly lower than before, and presumably you feel that these readings are not correct.

Did you ask the optician for an explanation for your bad eye strain and near vision difficulties? If so, what please did he say?

If the above is your new prescription, I'm just not sure what to say. It contradicts that you feel that you can see better in your right eye with 1.50 Cyl than none at all, and your previous comments that your left eye could not be corrected to 20/20 until they increased the cylinder.

I'm not really sure what to suggest doing next. If I was you, and I have no idea of the costs of eye tests in the US where I presume you live, I would give up with the idea of dilated exams, finding hyperopia, trying to work it all out for yourself, and would ask for recommendations from friends and family of a good optician, who has prescribed glasses that they are very happy with, and make an appointment.

When you arrive for the appointment, I would say that you are worried that you may have been subjectively choosing the wrong lenses in recent eye tests, as you end up with a prescription that causes you bad eye strain even in the distance, and near vision difficulties. I would ask therefore if after testing your eyes in the conventional manner, he/she could please independently check your prescription via a retinoscope to see whether they would have prescribed the same prescription if you had been unable to communicate.

If there a difference in the two prescriptions, I'd ask him/her to show you the two prescriptions via the trial lenses, so that you can see the difference between what you have chosen and what the optician would prescribe for you if you were unable to communicate. If the lines of the letters look narrower and more defined with his/her choice, it may be that you have been choosing the option when the lines look wider, mistaking a line that looks slightly wider because it is slightly blurred, as being bolder, and that you are choosing what you perceive as bold or dark, rather than sharp and well defined. I'm not saying for one moment that you are doing this, just suggesting this as a possibility from something you said in a previous post about choosing the darkest option.

I'd ask the optician to test your visual acuity with both prescriptions, to see whether it differs, and if it is about the same with both prescriptions, it may be worth asking if you can try his/her prescription determined via retinoscopy for around a month, since you are having bad eye strain with your current prescription anyhow.

Please don't be offended, but rather than a series of poor opticians/appointments going wrong, you may inadvertently be choosing the wrong prescription, and having a prescription determined for you as if you were unable to communicate, may be what you need, as again meaning no offence, I feel that you have analysed your own vision so greatly, that it may be better to now step back and trust someone to do it for you, as your last two appointments have not been very successful.

I really hope that you are not offended by what I say. I have no intention of upsetting you, and wouldn't have wasted my time replying to you all the time, if I wasn't genuinely interested in helping.

I feel that a lot of the issue is that you have analysed your own vision so greatly and come to so many of your own conclusions, that it is now confusing the issue.

With me personally, I can see better under corrected than over corrected because even at the age of 44, I have enough accommodation to add a little bit of extra plus, whereas there is nothing anyone can really do to take away too much plus.

Being only 21, I'd imagine that you could quite easy add the extra plus if you are under corrected. I fully appreciate that you mention bad eye strain, which suggests that you are working hard to add extra plus, but since you have become so anxious regarding your eyesight, maybe you are just straining because you feel that your vision is blurred/your prescription is too weak, and not because you are genuinely straining to add needed extra plus. So much of vision occurs in the brain, and the human brain/emotions are so powerful, that for all of us, it just isn't always easy to work out quite what is going on.

I'm not suggesting for one moment that your concerns are not genuine or all in your head, only sharing my experience gained from many years of playing the trumpet, that a lot of the time you are not doing what you think you are doing, and over analysis leads to paralysis.

I am again very sorry that things didn't go as you hoped.

My very genuine and heart felt best wishes to you.


astigmaphile 18 Jan 2018, 18:53

I have to wonder why any one would have 21D of cylinder error. Sounds like some kind of corneal problem like keratoconus or pellicid marginal degeneration.

Weirdeyes 18 Jan 2018, 12:04


It went horribly. He was a nice doctor, but didn’t know shit about refractive error like I expected. The autorefractor also sucked. It said I’m R +0.25 +0.25 L +2.75 +0.75. They also used weak dilating drops that never totally relaxed my eyes. My mom had a lot of faith in him just because he’s an ophthalmologist. Since they tested my corrected acuity as my drops were starting to work my left eye couldn’t see the 20/20 line. I know it got 20/20 before. The drops definitely blurred my left eye more than my right eye.

Lou 18 Jan 2018, 07:20

Hi Weirdeyes

Hope that it goes well for you.

Best wishes


Weirdeyes 18 Jan 2018, 06:45


Still a few hours away. I’ll see what I can do.

Lou 18 Jan 2018, 06:31

Hi Weirdeyes

Presumably this is the day of your dilated eye exam.

Please update us at your earliest convenience.

Best wishes


Weirdeyes 18 Jan 2018, 06:21


Same with me. I kind of have an idea though. I knew this guy at school who wore high plus glasses. One of his eyes looked noticeably like a different shape. So I assume he has bad astigmatism in one eye. It definitely wasn’t -21, but probably worse than average.

Savian 18 Jan 2018, 05:16

Wondering how the eye appears behind such a lens.

Weirdeyes 17 Jan 2018, 19:22

I guess this is the astigmatism equivalent of a myodisc I was asking about.

-21 cyl lenses

The glasses

astigmaphile 17 Jan 2018, 18:57

Crystal Veil,

I could not find the really high cylinder. My cylindermania is going berzerk just thinking about it. I have never heard of prescriptions that high.

High Myopic 17 Jan 2018, 16:51

Can make me some -40 diopter or higher eyeglasses? I really want to have a stronger myodisc pair than my -38 diopter pair. Whats the strongest rx they can go to?

Weirdeyes 17 Jan 2018, 16:39


Great Instagram. Especially for my cylindermania. I’m curious what people look like wearing high cyl. I saw some -21 cyl on there!

Crystal Veil 17 Jan 2018, 16:31


amazing to see a lens with astigmatism of +17.25 on that site. Thanks for posting!

LikeGlass 17 Jan 2018, 15:43

Guess the link would help!!!


LikeGlass 17 Jan 2018, 15:42

Crazy high Rx, hope they show the finished product, lenses in frames.

Lens prep -36d

Lip 17 Jan 2018, 15:39

Cactus Jack


My PD is 66.


Lip 17 Jan 2018, 09:11

Cactus Jack,

Can you please help me with rx for Prism glasses ?

Not sure what zenni offers,I think the highest is 5 ,base in or out.(hope that's correct)Iwould prefer where the thickness of the lense is in the inside.

This is my Current rx, without the add (2.50 )Zenni only do Single Vision Prism Glasses

R sp +0.25 Cyl -0.25 Axis 80

L sp +0.50 Cyl 0.50 Axis 102

Over the years you"ve explained to me about Prism Glasses ,I understand , and would Like to Try the highest available on Line.

Regards,Lip (Leo)

Maurice 12 Jan 2018, 18:26

Many thanks for the suggestions on purchasing lined trifocals online. I start perusing those sites this weekend.

Curt 12 Jan 2018, 06:31

JEMoptical also sells lined trifocals online. I have two pairs from them.

EyrTri 11 Jan 2018, 17:29


Yes trifocals (with lines) are available online. SimplyEyeglasses and LensesRX will do that for you.

I am very fussy about the height of my trifocal segments, so what I prefer to do is purchase a frame that I want to use. When I get the frame I measure where I want the segments to be and use one of the internet lens replacement companies to put trifocals in that frame. Recently I used Replacement Lens Express to make lenses for several pairs of glasses. They made them just as I asked, the prescription was accurate and the turnaround time was short.

Any questions let me know.

Soundmanpt 11 Jan 2018, 17:04


Just to be sure I went into Zenni ( and yes lined bifocals are still available. With Zenni if you were to choose Say #220421 glasses it cost of single vision would be $12.95. It would bean additional $17.95 to make that same pair of glasses into lined bifocals.

Maurice 11 Jan 2018, 15:45

Quick question---are lined trifocals still available? Who sells online?

Weirdeyes 14 Dec 2017, 04:08


I don't actually have a lazy eye. Just smaller image size in my left eye. When they were testing my left eye when I first got glasses I noticed the letters looked too small for me to see. It wasn't obviously blurry to me. The 20/40 line looked like the 20/15 line. When they uncovered my left eye I was shocked at how big that impossibly small line actually was. I don't know what my best corrected acuity was at that point. Maybe 20/50. I had no cylinder correction. Eventually it improved to 20/30 and I had -0.50 cylinder. At that point I was sick of being the freak with the lazy eye, so I just willed my left eye not to be lazy anymore. During my next eye exam when they were testing my left eye with a +3.25 contact lens in I noticed a pretty big line on the eye chart was unreadable for me. It was smudged looking. So I had 20/50 vision with that contact lens and felt like a failure. Bu then I discovered my left eye actually needed -1.25 cylinder. After that it could see the 20/20 line. So either my efforts worked or my left eye wasn't lazy to begin with. As a kid I remember loving 3D movies. I think my relatively good depth perception kind of hints at me not really having a lazy eye. It's also interesting how my left eye's acuity seems to be correlated with how much cylinder it needs. The 20/20 line looks pretty small to me, but I have that problem with both of my eyes. It's like they're both lazy.

SC 14 Dec 2017, 03:05


It makes sense that plus contact lenses magnify less than glasses as they are closer to the eye.

I don't know what the factors are for image size bare-eyed. My eyes are not the same. The lazy eye image is smaller than the good eye image. I don't know whether this is what leads to lazy eye or is as a result of it.

My Rx is not quite as diverse as yours OD +1.75 OS +4.5 but I've never got the left eye fully corrected so just have +2.0. There seemed no point @4.5 I still only get 20/50 or 20/60 and my brain only uses the image for peripheral vision anyway

Weirdeyes 12 Dec 2017, 12:38

Is it normal to NOT experience image size differences when you wear glasses with a difference in prescription? They're currently R+0.75 L+4.25. I actually notice things look smaller through my left eye when I wear contacts.

Cactus Jack 11 Dec 2017, 17:15


Many years ago Optical4Less had a special makings department that would make specialty lenses. I don't think they do that anymore, but you might shop around some.

From an optical standpoint, it really does not matter how thick the lens is in the center, the power of the lens is the difference between the curve of the front surface and the curve of the back surface AND the Index of Refraction of the lens material.

For example a -7.00 lens might have a front curve of +1.00 and a back curve of -8.00. Typically, a lens of around -8.00 power will have a front surface curve of 0.00 (flat) to minimize the curve of the back surface and minimize edge thickness.

Low Index safety glasses have thick centers for safety reasons. Because of its strength, a Polycarbonate lens can be a lot thinner than a CR-39 lens.

The biggest disadvantage of glasses with very thick lenses is the weight on your nose.

You might think of a reason for wanting some very thick lenses in your glasses. One possibility i that you are to have a part in a play where the character is very nearsighted and wears extremely thick glasses.

Another way is to consider GOC with a high prescription.


Billy A 11 Dec 2017, 14:16


Ice cubes? No :) -7 will be about 7-8mm thick (low index)

ZR 11 Dec 2017, 11:33

What do you consider thick for rimless/semi-rimless? I'm a -7.00 and am thinking about getting a semi-finals with a 53 width. Will they look like ice cubes?

Glasses Lover 01 Dec 2017, 13:33

Anonymous poster below...

Please elaborate more regarding reducing PD distance to get prism to effectively get thicker lenses. I've never heard of this and am very interested.

 01 Dec 2017, 05:58


Get as large frame as possible. Reduce your PD distance which effectively introduces prism correction

NNVisitor 28 Nov 2017, 22:02

A thin coating that can turn prescription lenses into night-vision glasses using invisible infrared light based on nan-photonics technology is being developed by a team at Ben-Gurion Universty in Israel.

I, Glasses 25 Nov 2017, 15:12

I am about to get new glasses, and I want them to be as thick as possible with my actual Rx, which is -4 sphere, with some additional correction for astigmatism. Aside from the lens material being CR-39, what other optical 'tricks' will increase their thickness. I intend to get rimless, by the way, vintage-look Artcraft-Rimway. Thanks.

Weirdeyes 25 Nov 2017, 07:32

I was bored so I asked some people on this app if my glasses look fake. 64% said they look fake and I was showing the distortion from my +4.25 eye. I guess most people don't notice, but one commenter said he noticed the distortion but they didn't look as strong as his glasses. No clue what his rx is supposed to be.

High Myopic 18 Nov 2017, 17:26

What do you think is the rx of these half rimless myodisc glasses? Minus 15 or more diopters?

astigmaphile 14 Nov 2017, 09:55

I'm =2.50 at155 in my left eye and the lens isn't thick, especially the pair Zenni made with high index lenses that I did not specifically order.

Weirdeyes 14 Nov 2017, 01:38

This may be a dumb question, but here it goes. Are high cylinder lenses thick? Like maybe +2.00, -4.00. +2.00 and -2.00 aren't exactly thick lenses, but would they be thick in this case?

Lou 10 Nov 2017, 10:51

Hi guest

In minus cylinder form, your prescription is:

R: -1.25 Sph -0.75 Cyl Axis 45

R: -1.25 Sph -0.50 Cyl Axis 165

Although not a strong prescription by any means, yours is hardly the weakest and I wouldn't have thought that it would look like plain glass.

My prescription is:

R: +0.50 Sph -0.50 Cyl Axis 92

R: +0.25 Sph -0.25 Cyl Axis 85

Only to other eye issues, I wear mine all the time. I'd say that my prescription is very weak. You can't really see any prescription in my glasses when I wear them, but if I take them off and look at them, you can clearly see that they are prescription, particularly the right lens.

Nobody has ever asked me about my prescription, so I don't think that the majority of people take much notice.

I hope that this will help.


Soundmanpt 10 Nov 2017, 10:10


This comes up often. Most people,with the exception of those in this forum, don't pay any attention to another persons glasses except for looking at the frame of the glasses. You're prescription is more than enough for full time wear and anyone trying on your glasses will understand why you wear them. So it's not like you have a really weak prescription that others may not even notice if they were trying your glasses on.

guest 10 Nov 2017, 07:26

I'm very slightly short sighted and therefore have a very low prescription. The lens I have look almost like zero power, like plain glass. I don't like wearing them since they look fake but they do seem to make a tremendous difference to the sharpness of my vision.

My prescription is L-2.0

+0.75 @ 135 and R-2.0 +0.50 @ 75

Can you tell me if its possible to get lens made thicker than they would normally be in CR39 1.50 ? I'd really like to have lens like the thickness of -4.


aviator -oo- 26 Sep 2017, 02:14

Thanks, 30calcat . It is not so uncommon to see RX lenses in large sunglass frames, so it is good to know that 75mm is not always the limit. I'll do some searching for suppliers of 81mm.

aviator -oo- 26 Sep 2017, 02:14

Thanks, 30calcat . It is not so uncommon to see RX lenses in large sunglass frames, so it is good to know that 75mm is not always the limit. I'll do some searching for suppliers of 81mm.

aviator -oo- 26 Sep 2017, 02:14

Thanks, 30calcat . It is not so uncommon to see RX lenses in large sunglass frames, so it is good to know that 75mm is not always the limit. I'll do some searching for suppliers of 81mm.

30calcat 25 Sep 2017, 18:34

When you look at lens blank catalogs 75mm is very common, though some are 81mm, especially for sunglasses

aviator -oo- 25 Sep 2017, 05:27

Can someone tell me what diameter un-cut CR39 lenses come in as stock items, prior to being crafted to fit in a particular frame. I have some large frames which I want to have fitted with rx lenses (around -4) and would like to know what the limitations are. I appreciate that PD has to be taken into account. I recall going into an optical store some years ago with some large sunglass frames and the assistant said they would require a non-standard larger size of lens. I assume these were still CR39.

High Myopic 20 Sep 2017, 17:46

What do you think is the rx of these two pairs of myodisc glasses?

First pair.

Second Pair.

NNVisitor 06 Sep 2017, 21:57


I have worn contact lenses for many years. More than thirty years. Prior to wearing contact lenses I wore glasses full time for about ten years. Prior to that I avoided wearing glasses much of the time until my vision was utterly awful. I really did not like to wear glasses in public. About 1970 some people then many were wearing tinted prescription eyeglasses. Some blue tint. Some grey tint. Some brown tint. I broke my glasses one day and they couldn't be properly fixed. My prescription went up again to -8 with some astigmatism as well. I got my first metal frames then and my glasses were tinted. A woman with a similar prescription to mine once commented to me that my glasses were slightly stronger than hers. A good friend of mine thought I was wearing sunglasses. This shows how different an observer's perception could be.

Some people are good at guessing someone's prescription. Others are clueless and can't tell minus lenses from plus lenses.

I have never had polished lenses and I never will. Our perception dictates what we prefer when it comes to eyeglasses. Some of us are acutely aware of the power of and the look of glasses prescriptions. Others don't give much thought to it and can be quite clueless about prescriptions and how lenses look.

This can all be explained by the psychology of perception. The fact is that we all filter out some aspects of what we see. That's why some of us remember exactly what someone was wearing and others can't remember.

astigmaphile 06 Sep 2017, 21:31

Cactus Jack,

I wear plus cylinder lenses and notice that they also have so called power rings.

SoCal 06 Sep 2017, 20:16

Thanks Cactus! I was just curious. I noticed the difference when I was holding my specs outside and compared them to their look inside and it had me wondering. I rarely wear my specs but I'm finding myself wearing them more and more lately as my contact lens tolerance is going down. Anyway, thanks for the info!

Cactus Jack 06 Sep 2017, 20:13


I suspect the sunlight effect you asked about is caused by sunlight brightly illuminating the edge of the lens and making it more visible in the reflections.

I want to try using a black marker on a frosted lens edge to see if that affects the power rings on an old lens, but have not tried it. I might try it first with a dry erase marker, which might be removable. A permanent marker might react with the lens material and really be PERMANENT. It should not have any effect on the refractive power of the lens.

Let me try it first on an old lens.


Cactus Jack 06 Sep 2017, 20:02


What some people call "Power Rings" are actually internal reflections of the outside edge of MINUS lenses. Frosted edges appear white from the front of the lens. Polished Edges can also be seen, but they tend to appear as a mirror like surface. You can demonstrate this effect by licking your finger (for good contact) and holding it against the outer edge of the lens while looking from the front.

The internal reflections can be minimized by using a very light tint in the lens.


SoCal 06 Sep 2017, 18:06

Why do lenses appear thicker in sunlight if you don't have polished edges? Is it the material used and is the whiteness something that can go away in the sunlight by having polished lenses? Just curious.

HighMyopic 29 Aug 2017, 15:41

Have you found the Indian manufacture of these +64 diopter glasses yet?

HighMyopic 18 Aug 2017, 08:50

How much did you pay for the glasses? Can they be shipped to the USA?

Ian 18 Aug 2017, 07:43

High Myopic

I cannot seem to find a photograph of the glasses, I will keep looking.

Yes the lenses were thick. It looked like they had a small glass marble at the centre. They were not suitable for walking around.

HighMyopic 18 Aug 2017, 06:10

You have a pic of your X16 glasses that you mislaid? The lenses were very thick?

Ian 18 Aug 2017, 06:01

High Myopic,

A couple of years ago I bought some magnifying spectacles for close work. I have mislaid the glasses but they were magnification X16 with an Rx of around +64D. They were only suitable for very close work. I will try to find the company's name, I think they were based in India.

astigmaphile 17 Aug 2017, 20:04

I have never seen so much high cylinder in one place. Twenty one diopers is just unbelievable. The whole thing is making me drool.

HighMyopic 17 Aug 2017, 18:59

Can this company make high plus lenses that are over +48 diopters? I now want to have a pair of glasses that is over +50 diopters. perfectly +60 or more diopters. My +48 diopter glasses are still very nice to wear but i now want stronger plus lenses.

LikeGlass 17 Aug 2017, 18:11

Interesting lens work at this shop. -31 ??? Yikes

Soundmanpt 08 Aug 2017, 08:21


Anytime you come across a pair of glasses and after wearing them a short time if they don't feel right you need to take them off right away. I know sometimes you can tell if they have prisms by the edge thickness but its no so easy if it is only a small amount of prism. But even a small amount could damage your eyes. You have experimented with enough glasses with many different prescriptions to what feels right and what doesn't. Are you still working at the landscaping business? You don't wear glasses during the day at work. You only wear your strong glasses on the weekend and in the evenings. But since you moved are you comfortable wearing glasses around your neighborhood on weekends and evenings now? You had found a nice pair of progressives that you seemed to like quite a bit because they had a nice minus prescription for distance and the add allowed you to read small print comfortably as well. Are you still wearing them at times or have you found other favorites you like better. I'm sure you have added to your collection considerably since you last posted pictures of glasses you have bought. I look forward to seeing pictures of some of those glasses.

María 07 Aug 2017, 05:39

Thanks for the clues, Cactus Jack. Nice to know there's those ways, but it really seems hard. I'll look for the test you mentioned.

Antonio, Soundmanpt, don't worry. I only wear for prolonged periods the glasses whose prescription I know for sure. I don't want to hurt my eyes either, so if any of my glasses give me some discomfort, I don't wear them for more than a few minutes.

Cactus Jack 06 Aug 2017, 15:50

Assuming both eyes have the same prescription and a VD of 10 mm, It would be very close to:

OD Sphere -7.00, Cylinder -2.25, Axis 180

OS Sphere -7.00, Cylinder -2.25, Axis 180


NNVisitor 06 Aug 2017, 15:47

-6.50 contact lens would be -7.00 in eyeglasses. The astigmatism correction should be the same. In some soft contact lens brands the astigmatism correction is in -.50 increments thus when converting to contact lenses from an eyeglasses prescription it's the same if not available go .25 lower. In contact lens astigmatism correction. The contact lens axis may only be in increments of 10 ot 20 degrees in some soft contact lens available for astigmatism correction. Only an eye exam by a qualified ECP can confirm your exact correction requirement.

 06 Aug 2017, 15:02

Any general guess as to what the following contact RX would translate to in glasses???

sph. cyl. axis

-6.50 -2.25 180

Soundmanpt 05 Aug 2017, 17:55


It has been a long time since you last posted. It seems that you're still buying used glasses. If those glasses in anyway don't seem right you shouldn't wear them. It doesn't take too long wearing glasses with prism to completely ruin your eyes. I'm sure you don't want to be seeing everything in double vision or cause your eyes to become cross eyed.

Cactus Jack 05 Aug 2017, 15:09


It is not always easy to tell if glasses have prism. It depends on how much prism and which direction the base of the prism is oriented

Here are a few clues:

1. Compare the edge thickness on opposite sides of the lenses, both horizontally and vertically. The thicker edge is the Base direction. A difference is not an absolute guarantee that the lenses have prism. It is common for inside edges (next to your nose) to have thinner edges in Minus lenses that do not have any prism. It depends on the width of the lenses.

2. Sometimes you can tell by looking at the lenses from the front. Lenses with prism will have different looking edges as viewed from the front of the lens.

3. If you can see pretty well with them at a distance of 3 or 4 meters (10 to 15 feet, you might consider doing the Simple Prism Test as described on the Vision & Spex site.


antonio from lenschat 05 Aug 2017, 15:01

Please Maria don't wear glasses with prism correction,

i heard if yiu do so you get very fast dependent on the same prism correction, if you don't wantvto see double images your whole life. Don"t know that's true, but please don't try

Best regards antonio

María 05 Aug 2017, 14:13


Long time no see, and here I am, looking for an answer. Damn me! haha.

I wanted to ask... is there a sure way of knowing if a pair of glasses have any prism prescription? I bought a used pair that feels... a bit strange and I fear they do have it. How can I know just by looking at them?

Thanks in advance,


30calcat 30 Jun 2017, 06:43


Jack 29 Jun 2017, 11:39


Your glasses look really fantastic. The photography shows them off to the extreme. They really interest me. Your eyes must look very small behind those powerful lenses.

What are the lenses made of to make them look so thick?

30calcat 28 Jun 2017, 18:12

No prism

Jack 28 Jun 2017, 17:01


Any prism?

30calcat 28 Jun 2017, 16:11

-16.25, -15

Jack 28 Jun 2017, 16:00


What is you full prescription?

30calcat 28 Jun 2017, 15:21


Most people would not consider your glasses thick. I wear these much thicker glasses in a semi-rimless frame every day:

I am comfortable wearing them and they have never attracted negative attention. The very occasional questions I get are probably from a fellow OO.

Mel 28 Jun 2017, 13:59

Thanks for the input, Paul. You bring up an interesting point, though I can't say that I fully agree: as an OO, I've always preferred semi-rimless to rimless, especially in a high-prescription, as a semi-rimless somehow "defines" the thickness of the lens more, whereas a rimless kind of melts into the face, regardless of the prescription.

In any case, since I have a life outside of my fetish, my goal was to figure out whether my glasses (here is an updated photo: look ridiculously thick. I'm in college and my prescription is still rising steadily, so I anticipate something like a -1 increase to a -7.75 at my next exam. I'm trying to figure out at which point I'll have to bite the bullet and go for full-rimmed.

Paul 26 Jun 2017, 19:21


I think rimless and semi-rimless should NOT be grouped together for your question. With rimless, a little thickness looks good because thin rimless glasses just disappear on a person's face...the thickness, in effect, serves as the "frame" and I think it's a positive effect (even from a non-optic-obsessive perspective) up to a reasonable thickness (like 1/4" or 7mm maybe).

I feel completely differently about semi-rimless, which are typically a very "dainty" or lightweight frame that is easily overpowered by lenses more than a few mm thick (in my opinion).

My $0.02 only. And I agree with others that most people don't notice lenses regardless. For example, I went from wearing -3 glasses to -8 full time and no one ever said a thing or seemed to notice at all.

HighMyopic 26 Jun 2017, 18:33

What do you think is the rx of these lenses? They look like myodisc lenses.

NNVisitor 24 Apr 2017, 09:17


I just checked the image you posted. I think the glasses were well chosen and do not look very thick. Mine are several D higher and I have astigmatism as well. I don't know what index has been used on my glasses other than that they're high index glass lenses. I know that there is a 1.9 index zeiss glass lens available which is the thinnest that I know of. This type is very expensive and I'm sure mine are not that lens type.

Rayray 23 Apr 2017, 00:52

Hi Mel, for your prescription and the index of lens you have (1.67) your lenses are about normal - I have a prescription of about -8.5 so my glasses are very similar. If you don't want the thickness to be noticeable a thick plastic frame is the best option - rimless or semi-rimless will just draw attention to your lenses. A lot of people are very unaware of glasses lenses however and still won't think your glasses are thick.

Maxim 20 Apr 2017, 16:15

To Anonymous No. 1, No. 2, No.3 ..... No. 99

I must admit, you are right. Stealing is forbidden, that starts in the Holy Bible and continues in our legislative systems.

Not a good idea.

Believe it or not, during our school years, we collected old glasses for experiments in the physics lessons, optics. Then we learned about the camera, the human eye, the telescope and the binoculars, and camera lenses, not to forget the microscope, and much more.

Mel 20 Apr 2017, 15:15

NNVisitor, Antonio,

Thanks for the advice. It seems that I did pick a frame that is way too large, and that's why the lenses are so thick.

Could you give me an example of a semi-rimless frame that would minimize thickness? And what ET do you think would be acceptable in a rimless/semi-rimless?

?!?!?!?!?!?!!! 20 Apr 2017, 14:05

maxim What Are You Talking About? Stealing is Stealing is Stealing. With Your Logic, I Ask Is it Better to Steal from A Person or a Bank? Some Logic You Have There, Little One. The Other Anon Poster Is Absolutely Correct.

High Myopic 20 Apr 2017, 10:38

I cannot even see peoples heads let alone their faces. I am totally blind as a bat.

LiP 20 Apr 2017, 05:51

High Myopic

Did you miss my post 14 April? Thanks.

Still trying to work out ,how are you able to wear +48 glasses without using contacts (GOC)?

Can you see properly, if yes , how, Please?

HighMyopic 19 Apr 2017, 20:39

I have not got them in the mail yet. They should come next Monday.

30calcat 19 Apr 2017, 20:18

Yes they look as thick as my 17mm thick lenses. I am surprised the lab edged the lens with so much of the thickness on the back side. Do the nose pads even make contact or does the inside edge dig into your nose? Or do you wear them further down your nose - they look like reading glasses?

HighMyopic 19 Apr 2017, 18:07

You think this 15+ base in prism glasses pair has half inch thick lenses?

NNVisitor 19 Apr 2017, 15:18


Correct. I have been very careful to not get large frames. Also I have high index lenses in them. Costs more for them but worth it. Compared to 1.50 index lenses which I had years ago before I was told about the thinner high index lenses. Smaller frames with high index lenses have resulted in lenses as much as 50% thinner.

Maxim 19 Apr 2017, 14:48

I compare these photographs to the pictures of lenses with 8 prism diopters, that I remember.

I would say, yes, 15 prism diopters or more.

HighMyopic 19 Apr 2017, 14:38

You think there is at least 15 base in prism in these glasses?

The lenses look like super thick wedges with rounded fronts.

The back of the very thick wedges

Maxim 19 Apr 2017, 14:27

To his Eminence, the Right Hon Mr Anonymous:

.... and Greenpeace or the Red Cross, or UNICEF or the Churches?

They are collecting penny per penny, cent per cent, from poor people in the street, and their Directors, or Bishops, or whatever tehy are called, are living in big houses, tehy are art collectors, and they are chauffeur driven in fine limousines.

Which problem is worse?

 19 Apr 2017, 13:37

@MAXIM = your sense of logic seems impaired. imagine it was cars for charity. what if you picked up 8 cars with a tow truck, and kept 3 cars for yourself. how is that ethical. i think you no the answer. it is larceny.

antonio 19 Apr 2017, 12:44


smaller glasses would help them

not to get that thick

in general,

best regards, antonio

Mel 19 Apr 2017, 12:15

Interesting, Jared. My glasses are only around -7, fairly high index (1.67), and yet the edges still look like ice cubes (link if you're interested:

What am I doing wrong?

Jared 19 Apr 2017, 11:14

Hi Luke-

You ever on ES chat? Would be happy to exchange info with you there.

JP 18 Apr 2017, 13:38

Thanks Maxim.

I'd enjoy playing around with lenses to work this out, but would like the confidence of a lensometer assessment of the prescription, particularly as I'm interested in a pair of (minus) lenses with cylinder and add.

Luke 15 Apr 2017, 16:20

Jared and Patrick B

Can you please share any pictures of the amazing glasses.

Patrick B 15 Apr 2017, 12:41

I agree with Jared. Most dispensing opticians don't have the expertise when dealing with high-minus prescriptions and aren't aware of the available options. My prescription is -26, and I have lenses which are approximately 4 mm thick in 1.8 high-index lenses. They are, of course, blended myodiscs set in negative carriers. Cosmetically they look pretty good and most people aren't aware of the strength of the lenses unlike my other pairs of glasses which have conventional full-frame lenses. My last pair are in a small 47mm frame and are 9mm thick at the beveled edges. They look so much stronger than the myodiscs especially since they are heavily biconcave. I've been counseled against rimless/semi-rimless frames because they don't provide as much support for glass lenses and are thus more fragile. Still, I might just try them for my next pair.

Today I saw a guy who probably had -12s in a frame that was perhaps 50/52mm in width. I'd guess he had the 1.74 high-index lenses. The combination of the frame and the lenses meant that they were relatively thin and the frame covered the edges perfectly. That said, there was on getting away from the fact that his lenses were quite strong when viewed dead on. He also had that classic high-myopic body language meaning that he always turned his head whenever he wanted to view something off to the side.

Jared 15 Apr 2017, 09:37


Arbitrary means let's not deal with this and suggest a non semi-rimless frame. My brother's best friend is an optician and he sees this daily. When customer is advised that a -6 or more will be somewhat thick lens and wants semirimless then told a high index lens, at additional cost would cut down on the thickness. He said most of the time they opt for a different frame. My brother's Rx is -25 and he wears semi rimless which are 4mm thick.

So a viable option is available for hi myopes who want semi-rimless without thick lenses. Just ask!!!

30calcat 15 Apr 2017, 04:27

You can also use a lens clock to approximate the lens power yourself

Maxim 15 Apr 2017, 00:43


What to say to the optician?

Tell him/her, you would donate glasses via a collecting organisation. But attention - many opticians are part of such projects - you must keep them!

You could also collect and donate glasses - see Google: "donate glasses".

If you collect e.g. 20 glasses from family and friends, donate 15 and keep 5, it would ne morally alright ????

Maxim 15 Apr 2017, 00:23

We did the measurement of lenses in school, in physics / optics.

Did you get plus (magnifying) or minus (minifying) lenses.

For plus lenses it is quite easy, even with astigmatism.

Again it is easier, when you are used to the metric system, than to the inch / foot etc system.

Measurement of a plus lens (e.g. readers):

Go in front of a white wall with day daylight (ideally a sun beam):

A plus reader of + 1.00 makes a focus spot in 1 meter distance.

A plus reader of + 2.00 makes a focus spot on the white wall in 1 meter divided by two = half a meter = 0,50 meters or 50 cm.

A plus reader of + 2.50 makes a focus spot in 1 / 2.5 meters = 0,40 meters = 40 cm;

Plus reader +3.00 1/3 = 0,33333 = 33 cm;


Astigmatism lens, e.g. a +2.00 sph / + 2.00 cyl equal to + 4.00 sph / - 2.00 cyl makes two lines:

one line in 1/2 = 0,5 meters = 50 cm and

one line in 1/4 = 0,25 meters = 25 cm.

If you're interested, buy one or two cheap readers (here sometimes at 1,00 Euro = 1,== $, and try these experiments.

Minus lenses can be calibrated with a magnifying glass. Thoe magnifying glasses are very often at 10 diopters = + 10 - that means, their focus point is at 1/10 meters = 0,1 meters = 10 cm.

If with the magnifying glass + the unknown minus lens to be tested the result e.g. is a line or a focus point in 0,2 meters = 20 centimeters, then the result is 1/0.20 = 5 (= five diopters), the unknown minus lens has "weakened" effect of the +10 lens (magnifying glass) to +5.00. That means, the unknown minus lens has a power of -5.00 (minus 5 / nearsightedness).

The complete general formula is=

D = 1/f + 1 1/l -- in words:

The power in diopters (D) is the result of

1 meter divided by the measured focus distance in metrs or centimeters,


1 meter divided by the distance of the light source (e.g. sun) from the lens

You can do the same measurement in a dark room with a small lamp, with the same results.

JP 14 Apr 2017, 23:50

I have recently purchased a pair of used glasses and am really pleased with their style, fit and how well I can see with themy. I would like to know their exact prescription. I wonder whether any of you have experience of obtaining a prescription from a pair of glasses? What would you say to the optician?

Thanks everyone.

Trent 14 Apr 2017, 10:53

Mel, Jared,

Of course -6 is arbitrary. I'm just judging from my own response from Opticians. Edge thickness is a function of the eye size of the frame and the lens material being used. You can put lenses as thick as ice cubes in any frame, its really up to the end user.

Mel 14 Apr 2017, 10:29

Well, "cutoff" is obviously arbitrary" - but I guess I'm asking at what edge thickness they become very prominent.

Jared 14 Apr 2017, 08:39

Really Trent?

I wear semi-rimless -30s.

Trent 14 Apr 2017, 08:03

Hi Mel,

Usually -6 diopters is the cut-off for semi-rimless frames.

LiP 14 Apr 2017, 07:23

High Myopic

Still trying to work out ,how are you able to wear +48 glasses without using contacts (GOC)?

Can you see properly, if yes , how, Please?

antonio 14 Apr 2017, 03:51

hi Mel,

this should depend on the index of refraction

rimless glasses are made in:

Normal glas or cheap plastics might have n=1,5

which leads to thick glasses for the same strength of

let´s say -5 diopters.

n=1,57 or even higher index (until abut n=1,83 or so in mineral glasses) cost more and more, but lead to reduced thickness of the lens

hope that helps, best regards, antonio

by the way how strong is your prescription ?

and do you want thin lenses in rimless glasses ?

Mel 14 Apr 2017, 03:23

Out of curiosity, what is your threshold at which glasses become noticeably thick in a rimless/semi-rimless frame?

HighMyopic 11 Mar 2017, 18:55

Is there anywhere online I can get glasses stronger than +48 diopters? VisionEnhancers.UK goes up to +48 diopters but no higher. Pat told me that his glasses are +56 diopters. I now need to get glasses for me that are +56 diopters or more!! My glasses collection now must have glasses that are +56 diopters since I thought I have worn the strongest plus glasses ever at +48 diopters. But I was wrong.

30calcat 10 Mar 2017, 15:27

SPQ, I think if you asked a random sampling of people around you if they thought your glasses are thick they would probably acknowledge it, though a 1.6 index does a pretty good job of compressing it to a common looking lens.

SPQ 10 Mar 2017, 11:49

Interesting. Would you say 6.5 or so in a semi-rimless is enough to reach coke bottle status/make the glasses look truly thick?

30calcat 07 Mar 2017, 19:18

SPQ, based on lens calculators, you will probably get another 1mm of thickness, but some other unknowns may vary your results, such as aspheric lens curves. In theory, going from 1.67 to 1.6 will cause your lenses to look about 12% stronger in the same power, so your -7.25 will look like a -8 in 1.67 all else being equal.

SPQ 07 Mar 2017, 17:35

Thanks for the feedback, calcat. Yes, I do plan on using these frames, I like them a lot and I think they expose the thickness really well.

If I have a -.75 increase or so, that will bring my prescription up to -7.25 or -7.50 (I also have -.75 of astigmatism).

I'm thinking of doing 1.60 index -- if my current glasses are 5.5 mm or so thick on the edges in 1.67, what do you think the new thickness will be? Ideally I'd like to hit the sweet spot of 8 mm but not go over 10.

30calcat 07 Mar 2017, 05:24

SPQ, I think a lower index will look great. I have worn lenses much thicker than that without anyone taking enough notice to say anything. Are you going to get the thicker lenses filled in these frames?

SPQ 06 Mar 2017, 20:46

Out of curiosity, would you say these edges are thick?

These are my current glasses (-6.50 or so), definitely need a small increase and am trying to figure out whether a lower index would look ridiculous.

Like most here, I'm turned on by thick glasses but I want to strike a balance.

Would appreciate input on whether these would attract attention :)

Aubrac 05 Mar 2017, 03:36


Thanks for the info CJ.

The Axis is R 0.90 L 0.92

Despite the 2.50 cylinder I can see well at close and distance,maybe I have acquired some more cylinder in the right eye!

 01 Mar 2017, 20:27

It appears they have some Base Out prism in the 5 BO range.

HighMyopic 01 Mar 2017, 17:30

Are these thrift store glasses prism glasses?

Top down view.

Front View.

Cactus Jack 01 Mar 2017, 09:31


The partial prescription in - Cylinder notation is:

OD (Right) -4.50, -2.50 x ?? Add +2.50

PS (Left) -4.50, -0.75 x ?? Add +2.50

The Cylinder in the Right eye is pretty significant. I suspect you are primarily using your left eye because it is closer to your actual prescription. The Axis is important in the Right eye and less so in the Left because the Cylinder is less. The higher the Cylinder, the more important it is that the Axis be accurate.


rafa 01 Mar 2017, 02:24


I think that first you should go to any optical store and ask them to check out the prescription of the glasses for you. It would take them a minute and normaly they don't charge for that.

The chances are that, as you say, the sphere isn't as high as that. It wouldn't be the first time that the prescription alleged on Ebay isn't right.

Aubrac 01 Mar 2017, 02:15

A question I think for Cactus Jack.

I bought some great Silhouette rimless glasses very cheaply on Ebay.

My prescription is now about -4.5/4.75 both eyes with a little left eye cylinder and +2.50 add, and by luck I find the glasses absolutely fine for me, and the varifocal lenses useful.

In the case is a printed prescription that reads R -7.00 sph +2.50 cyl add +2.50, L -5.25 sph +0.75 cyl add +2.50.

Now the sphere cannot be -7.00 as I would not be able to see with them, and I remember a while back CJ saying that in some notation the plus cylinder can be subtracted from the minus sphere, so in this case what would the normally written prescription be, and why is it sometimes written in this way?

Any comments CJ gratefully received.

 26 Feb 2017, 09:45

Rafa and others

Did you made any new experiences ordering glasses over -20 desciption from ?

I want to order over -20 but ha en't got any experiences. Thank you

 26 Feb 2017, 09:42

Rafa and others

Did you made any new experiences ordering glasses over -20 desciption from ?

I want to order over -20 but ha en't got any experiences. Thank you

HighMyopic 22 Feb 2017, 17:27

I am Trying to order a pair of Coil Aspheric Hyperocular Microscopic 12x Magnifying Spectacles.

I am trying to buy them from the UK and have them mailed to the USA. The UK based website does not recognize Virginia. It says that it is NA instead of VA for Virginia. Then when you go back to edit the order, it cancels the order. I saw on eBay that the price would be 199 dollars if I bought them there instead of 65 dollars plus shipping. That is for the +14 diopter pair. I am trying to buy the +48 diopter pair.

Here is the pair that i am trying to buy.

Cactus Jack 22 Feb 2017, 07:37


I am pretty well convinced that most people don't notice differences in lenses, unless the appearance is radically different. They seem to notice frame changes, much more quickly. That is why we often suggest that people who are seeking to Induce Myopia order several pairs of glasses with increasing prescriptions, at the same time, all with the same frame. Once they get past the initial glasses comment period, they can change glasses without any further comment or notice.

The same thing applies to GOC if the first GOC combo is not a huge increase in the glasses prescription.


HighMyopic 21 Feb 2017, 18:39

Where can you buy glasses with +20 diopter lenses for cheap? Zenni only goes up to +12 dioters. I have +15 diopter glasses currently and want +20 diopter or more glasses. I have plenty of around -20 diopter myodisc glasses.

30calcat 21 Feb 2017, 11:44

Has anyone else here ever experienced that just changing the frames you wear is an effective way to draw attention and invoke conversations about your glasses? I usually wear these thick glasses into the office:

Last week I switched to these glasses, but no one said anything:

This week I decided to change things up with my browlines

I got some of the expected "are those new glasses?" questions that are fun to answer, but I also had multiple people asking about my lenses all of a sudden. "How strong are your lenses?" "Don't they have ways of making lenses thinner now?" This is interesting given that my "new" glasses are not thicker than what I usually wear, and are in fact more hidden behind the full-rimmed frame versus rimless. Perhaps these people have always noticed my thick glasses, but had no "excuse" to bring up the topic, especially if they were meeting me for the first time, but now that we are more familiar colleagues, the change in frames provided an opportunity. Do you all seize on these opportunities?

Another theory I have is that the bolder frames, or perhaps even just a change in frames, directed people's attention towards my glasses in general and they started noticing my lenses for the first time. Do the "new" glasses make my lenses look thicker?

minusglassesguy 19 Feb 2017, 04:03

Hi Edward & Myodiscs

I would really like to see what your glasses look like. I would really appreciate it if you sent me a picture. I wouldn't share on my tumblr blog unless you asked me to.

My email is

HighMyopic 18 Feb 2017, 14:49

Edward, Do you have Facebook? I'll friend you. I love to wear and collect very strong glasses.

Edward 18 Feb 2017, 12:41

Inglasses 18 Feb 2017, 09:21

Hi Edward

Not very often that I have seen a myodisc wearer here, would like to ask a few questions about them via email if poss?

Cactus Jack 17 Feb 2017, 04:44


I don't know why the lenses were experimental. Maybe a new manufacturer of the lenses seeking FDA approval.

The young man I mentioned, is a church organist and a teacher in a parochial school. I don't think either one pays a lot.

He lives in a city with a large medical school and teaching hospital. He was able to have the surgery at very low cos, if any, by agreeing to participate in a study that is part of the FDA approval process.

I may see him tomorrow and I will ask him why the lenses were experimental.


Ric 17 Feb 2017, 00:35

That s the worst thing, at first, i could not stop to look by the sides. Getting used to contact lenses, i felt clumsy and dizzy. Was pretty worried thinking on the amount they costed...

Edward 16 Feb 2017, 12:49


I know it seems daunting now but you will soon adapt to wearing myodiscs. When I was 16 I was devastated at the thought of wearing them, I deliberately chose to make the change as I moved from secondary school to sixth form college. Students were older, the teasing stopped and I just moved on. Yes people must notice my glasses but comments are few and far between. The myodisc lenses are thinner and the edges much thinner, just the edge of the bowls gives them away.

Like Patrick I wore blended but found the area between the bowl and carrier was a distraction. Now with regular lenses in a plus carrier I have learned not to look outside the central area, also plus carriers give very thin edges.

Cactus mentioned internal implants. They are not an option for me, as my Rx soared due to a quickly elongating eyeball my retinas became a problem, now no surgery unless it is absolutely necessary.

You have many choices of the type of lenses. You can chose.

astigmaphile 16 Feb 2017, 10:30

Cactus Jack,

I had cataract surgery on my left eye on 27 January 2011. There were IOLs with cylinder in them back then, but I would have had to pay for it myself. The monofocal IOL that I got was paid for by Medicare.

Cactus Jack 15 Feb 2017, 21:41


ICLs and IOLs go inside your eyes so dry eye is not a factor. Normally, IOLs do not correct Astigmatism. However a 30 YO acquaintance, who has diabetes, developed Cataracts and had surgery on both eyes in the last 3 weeks, He was offered was offered some experimental IOLs with Cylinder correction for his Astigmatism. Because they were single vision IOLs, he needs glasses to focus close. I spoke to him today and he is thrilled with the results.

The reason IOLs with Cylinder can correct Astigmatism is that the Axis of the Cylinder can be molded into the lens very accurately and the lens can be positioned in the Crystalline Lens Capsule very accurately. I don't know what his description was prior to the surgery, but hope to speak to him on Saturday.

I think you should strongly consider myodisc glasses and I urge you to learn as much as you can about vision and optics. You are going to be dealing with vision issues for many years in the future and you should take an active role in its management.

There are amazing vision developments occurring all over the world. IOLs with Cylinder correction is just one of them.


Myodiscs 15 Feb 2017, 20:46

Thank you all for responding. When it comes to contacts, my eyes really cannot tolerate them at all. I have really dry and sensitive eyes. I have tried contacts a few times, and it never ends well. It seems I really am headed to myodiscs.

Patrick B 15 Feb 2017, 16:28


I think you will enjoy wearing myodiscs in the future. My prescription is -26 with an insignificant amount of astigmatism, and my corrected vision is about 20/30, like yours. My corrected vision with contact lenses is around 20/25. Because myodiscs are thinner, they can be fit closer to your face which helps overcome some of the problems associated with vertex distance. They can also accommodate larger more fashion forward frames because they're thinner. To minimize their somewhat unusual appearance, I always get a negative carrier and have the myodisc bowl blended into the carrier. Most people don't notice them as being different unless they really take a look and actually consider what it is that makes the lenses different. Frankly, they're better-looking that my conventional lenses in their 45mm-wide frames, 1.9 high-index glass lenses and heavy bi-concave lens fronts. Good luck and let us know you get on with myodiscs when the time comes.

Ric 15 Feb 2017, 01:43

For not contact lenses wearers, sure would be easier to get used.

NNVisitor 14 Feb 2017, 16:31


Contact lenses can be uncomfortable when first trying them on. They have to be properly fitted for your eyes by an expert contact lens fitter. I've worn RGP lenses for years and typically only felt them on my eyes upon insertion. It takes time adapting to them. Uncomfortable at first which should go away within two weeks. If you do not have a problem with dry eyes then it's quite possible that you can adapt to them.

Edward 14 Feb 2017, 15:53


Do not be concerned about changing to wearing myodiscs. I had a very similar Rx to you before I left secondary school. Seven years further on my Rx is still increasing albeit at a slower rate now. The myodiscs are lighter to wear and as suggested there is a choice of styles, type of carrier and blended or regular. Once my Rx got even higher I chose a plus carrier and have got used to the refractive effects around the outside. As Cactus suggests looking through the centre of the bowl is best.

I cannot wear contacts due to prism correction and refractive surgery has been ruled out therefore I will have to wear this type of glasses. I see well enough but as time passes I cannot make out the distance detail as well.

Cactus Jack 14 Feb 2017, 15:20


I am not surprised and I understand. You may have tried Toric contacts that correct astigmatism, but they are very hard to get right. My prescription was and is nothing like yours. I tried several types of contacts, but could not tolerate them very well. I did not have much trouble with Sphere only Disposable, Daily Wear, soft contacts, they are very thin.

I have esophoria where my eyes want to cross and I wear glasses with Base Out (BO) prism. The optical characteristics were not very good, when I needed more than about 10 BO om each eye. I discovered that if I wore a +1.00 contact with my trifocals (with prism), I could see acceptably.

I'm 79. A few years ago, I developed dry eye problems and had to give up on the contacts and have to use clip-on +1.00 reading glasses to see OK.

You might be able to use either Internal Contact Lenses (ICL), that go between your Cornea and your Iris or the Visian ICLs by Staar Surgical that goes between your iris and your crystalline lenses. Both are implanted surgically through a tiny incision in the side of your cornea and they can be removed and replaced if needed.

The surgery is very similar to modern Cataract surgery where Intra Ocular Lenses replace your Crystalline Lenses, except the Crystalline Lenses not disturbed. Cataract surgery is scary to think about, but modern cataract surgery is almost a not event. I have had cataract surgery on both eyes and it took about 10 minutes for the actual surgery on each eye, it was totally painless. I was scared when I had the first eye done. The surgery and the results were so amazing, my first question, when the doctor checked my first eye, was "when can we do the other eye?". He said: Two weeks, to make sure there are no problems". I instantly said, "Please schedule it". That was 15 years ago and I have never regretted it for an instant. The IOLs for cataract surgery are permanent and can't be changed.


Myodiscs 14 Feb 2017, 14:22

I cannot wear contacts. My eyes fo not tolerate them. As for math and physics, I have taken up to Calculus 1, and no physics.

Cactus Jack 14 Feb 2017, 11:19


Yes, at some point, just increasing the prescription won't help. It may improve the sharpness of the focus, which you want, but the human eye cannot resolve image elements that are smaller than a certain size.

Other animals have better resolving power than humans. I saw this explanation on Wikipedia:

It is hard for us to image an animal seeing better than we do. But, many do. Raptors, or birds of prey, including the eagles, hawks and falcons can see up to 8 times more clearly than the sharpest human eye. A golden eagle for example can see a hare from a mile away.

Remember the biggest factor in image minification is the distance from the eye to the lens. At high prescriptions, a little bit goes a very long way because of the exponential power (square function) of Vertex Distance effects. The closer you can get the corrective lens to your eye's lens system, the less the minification and the better you can see.

It is possible that Myociscs may improve your VA, but the only way to tell is to try them. However, the Cylinder and Add in your prescription may complicate making Myodiscs.

May I ask if you have studied Math and/or Physics in school?

Myopia and Hyperopia are caused by a mismatch between the total power of your eye's lens system and the length of your eyeballs - distance from your Crystalline Lens to your Retina. Typically, Myopia means that your eyeballs have grown too much. The distances are pretty small, about 0.3 mm per diopter. If you need -22 glasses, your eyeballs are about 6.6 mm too long. Unfortunately, that places serious stress on the attachments of your Retina to the back of your eyeballs. If you do experience a Retinal Detachment, it can usually be repaired using a laser.

Astigmatism is usually caused by uneven curvature of the front surface of your Cornea. It is likely that the physical stress on your Cornea by the excess growth of your eyeball caused your Astigmatism.

I suspect that your ECPs are reluctant to do much more than change your glasses prescription, until your Myopia stabilizes in a few more years. Correcting part of your Myopia with a contact lens does not involve anything that cannot be reversed, but it does require a little imagination.

BTW, I am not an ECP. My background is Electronic Engineering and Computers. Fundamentally, I am a problem solver. My knowledge of Vision came from trying to find a solution to my own vision problems. My problems were much easier to solve than yours.

Here is a link to a paper you might find interesting.


Myodiscs 14 Feb 2017, 09:11

Cactus Jack

Okay, so just increasing my prescription won't help me see better?

I am 18, and I kind of live in both USA and Canada.

So, will myodiscs be a good option for me?

Ric 14 Feb 2017, 01:04

As Cactus Jack said, i found my AV improved, but i had long time to get used.

Cactus Jack 13 Feb 2017, 21:34


I need to get a bit technical to answer your question about your Visual Acuity (VA) with your new glasses,

I suspect you are encountering several problems with very high minus glasses.

Vertex Distance (VD) (the distance from the front of your Cornea to the back of the glasses lens) cause the majority of the minification effects of high minus glasses. The resulting elements in the images on your Retina much smaller than normal. While your Retinas have about 100 million Rods and about 6 million Cones, your optic nerves have only about 1 million individual nerve fibers. Most of the Cones are concentrated in the central area of the Retina, called the Fovea, where your HD vision occurs. The Retina does some image processing (compression) to combine the signals from the millions of Rods and Cones on to the 1 million optic nerve fibers.

As the elements of the image get smaller and smaller as a result of VD effects. Some image information may be lost during the compression process and your practical VA decreases.

Also, because of VD effects the effective prescription in your glasses varies very significantly as the VD changes. VD effects are the mathematical Square of the glasses power. In your case, it is more than0.50 diopters per mm.

Unfortunately, your significant Astigmatism makes the situation worse because your Cylinder prescription adds to the Sphere prescription in the Axis that is 90 degrees from the Long Axis of the Cylinder, listed on your prescription.

There is really nothing that can be done about the VD effects because they are dictated by the laws of Optical Physics. However, there may be a trick that might improve the situation. The trick is actually a variation on Glasses Over Contacts (GOC). The technique is actually used by one our local Ophthalmologists when preparing a High Myopic patient for Cataract Surgery to eliminate VD effects in determining the strength of the Intra Ocular Lens to be installed.

He temporarily fits the patient with a Contact Lens of enough Minus power to be able to use low power trial lenses in say the -2 to -3 range to complete the refraction. VD effects of glasses less than about -4 are almost insignificant.

It might be possible to correct most of your Myopia using Sphere Only Contact Lenses or most of your Myopia and some of your Astigmatism with an Internal Contact Lens or one of the Visan lenses that go behind your Iris. Of course another possibility is to consider an IOL as is fitted in modern Cataract Surgery.

Unfortunately, many Eye Care Professionals (ECPs) are rigid in their thinking and something innovative like I described above, may be "impossible" to contemplate.

May I ask your age and where you live?

Myodisc lenses are high Minus lenses where the prescription is ground into the back AND occasionally into the front of a "carrier" lens blank. The prescription part is called the bowl and the diameter of the bowl depends on the lens power. The higher the power, the smaller the bowl. The Power of the carrier can be Minus, Plano, or even Plus. Many people who wear Myodiscs find their VA improved with them. You have to learn to always look straight ahead thru the center of the bowl. If your eyes stray outside the bowl, you are looking thru the carrier and the sudden loss of correction can be disconcerting.

Hope the above is clear and is helpful.


Myodiscs 13 Feb 2017, 18:33

Cactus Jack,

My new prescription is -22.5/-5.25/110/+1.00

And -21.25/-5.25/135/+1.00

Cactus Jack 13 Feb 2017, 18:11


May I ask your prescription?


Myodiscs 13 Feb 2017, 15:18

I had an eye exam last Friday, and something the doctor said cought my attention. At the end, after checking my vision the doctor told me my prescription went up, and with my new glasses I will see, 20/30. He then went on to say, "Next time, we will look into fitting you with a pair of myodiscs." I have two main questions.

1. Why did he not correct me to 20/20?

2. Why myodiscs? I looked a little into then online, but could not find much about them.

Astra 30 Jan 2017, 22:13

Yes I did not count those surrounding the edges. I tend to have some minor scratches near the edge of lenses easily when I touch the frame

Astra 30 Jan 2017, 22:04

30calcat, Scratches do have some varieties, if minor enough they do not affect much. I have some pair of plastic lenses made 15 years ago. There are some deep scratches because I somehow scratch the lenses by my nails. Right in the middle of lens, so I understand it can be very noticeable at that position. But currently in question is, I receive some scratches on both of 6 year plastic lenses that appear to be less deep across the middle of lens , I can only find the scratches on the presence of light .

I frequently receive heavy smudges on my lenses which clears easily by cleaning machine, but scratches on plastic lenses I am less familiar. I do receive many scratches on my frames but that has less impact than now I have some on the middle part of lenses. I still considering whether to discard the lenses, because otherwise I see no major defect on these lenses

Astra 30 Jan 2017, 22:04

30calcat, Scratches do have some varieties, if minor enough they do not affect much. I have some pair of plastic lenses made 15 years ago. There are some deep scratches because I somehow scratch the lenses by my nails. Right in the middle of lens, so I understand it can be very noticeable at that position. But currently in question is, I receive some scratches on both of 6 year plastic lenses that appear to be less deep across the middle of lens , I can only find the scratches on the presence of light .

I frequently receive heavy smudges on my lenses which clears easily by cleaning machine, but scratches on plastic lenses I am less familiar. I do receive many scratches on my frames but that has less impact than now I have some on the middle part of lenses. I still considering whether to discard the lenses, because otherwise I see no major defect on these lenses

30calcat 30 Jan 2017, 12:08

The effects of scratches on lenses is as subjective as the effort of dirty lenses. Any measurement would have to be subject to a number of observed factors. One of my favorite lenses developed a tiny scratch that is hardly measureable, but it is right in the middle line of sight. When you look at a computer screen, the light hits it just right so that it is noticeable and hard to ignore. It is more of an irritation than an inhibitor, since it really has no effect on visual acuity. On the other hand, I can have numerous larger scratches near the edge of a lens and never notice it.

Astra 30 Jan 2017, 02:00

My lenses are plastic mr8

Astra 30 Jan 2017, 01:58

Now I have some enquiry about scratches.

How much scratches are considered "not suitable for wearing" ?

Are there any criteria for scratches, how much scratches are tolerated ?

I have read your posts dated 20161212 . Currently I have several pairs of plastic lenses exceeding 3 years . So I can safely assume my plastic lenses are all brittle now. The newer pairs have been used for 1-5 years are scratch free .

But one pair have been used for 6 years. Now I tend to use this pair in bathroom or some locations because this is the pair I intend to discard. I inspect the lenses today 20170130, both lenses show minor scratches , mostly on the posterior face, not easily noticeable when wearing . I am not certain how much scratches that can be tolerated . I lack the experience because I managed to keep some pairs of lenses scratch free for 1-5 years.

Should we check the reflection of the lenses ? When reflection from scratches exceeds a level, it is time to discard the lenses?

Cactus Jack 12 Dec 2016, 21:52


Depending on where you live and your prescription you may want to consider some new glasses from Zenni Optical. Their glasses are excellent quality and the cost can be very reasonable.

Fundamentally, the cost depends on the frame, the lens material, the complexity of the prescription, and any protective coatings you want. They offer glasses here in the US for as low as US$6.95, but the frame selection is limited. I often suggest ordering a low cost pair to see if you like the results and then ordering a more expensive pair with more frame choices. I recently helped a friend order some trial glasses for $6,95 + 4.95 (Anti Reflective Coating) and $5.00 shipping. The total was $16.90 and he received them in about 2 weeks.

If you are rough on glasses, I think they offer an anti scratch coating.


Soundmanpt 12 Dec 2016, 12:31


Very simple answer is that there isn't anyway to remove scratches form your glasses lenses. They have advertised a product that claimed to remove scratches but it has been proven that it doesn't work and those ads no longer run on TV. You need to replace the lenses provided the frames are still in good shape. If they are plastic and more than 3 years old the frame may even be too brittle to swap lenses.

Stepti 12 Dec 2016, 02:01

Hi. Does anyone know of a way to remove scratches from lenses?

Stingray 07 Dec 2016, 09:45

30calcat: Yes, I ordered them with anti-reflective coating. But you may be right. That coating could have worn off I guess from cleaning the lenses over a period of a year.

30calcat 07 Dec 2016, 08:14

Stingray - Do you have any coatings on the lenses? They could have gotten smudged/scratched/worn out over time compared to the other pair that has not see as much wear.

Stingray 06 Dec 2016, 14:00

Recently while driving at night, I notice that oncoming headlights have a starburst effect. I wear glasses with progressive lenses and was a little alarmed by this event. Right away I thought it was my cataracts ripening. Last year I ordered 2 pairs of glasses from glasses in one of their buy one get one free promotions. One of the frames I ordered was black with blue on the inside of the frame, the other a brown plastic frame. When I showed the new glasses to my wife,she remarked about the black and blue frames, "those are women's glasses". I decided never to wear them unless the other pair broke. Just as an experiment, I wore the black and blue glasses while driving at night and the starbursts were gone. Makes no sense. Both glasses were made by the same company, same prescription at the same time. Why would this be happening? Other than the starbursts on headlights and tail lights, my main pair of glasses are fine. Does anyone have an explanation?

Soundmanpt 04 Nov 2016, 15:55


You seem to have a pretty good understanding about vision and how the eyes work. I agree with you that it would seem like he might see better with the addition of some prisms added to his glasses. But I wonder why if he has mentioned this problem twice when getting his eyes examined and the doctors did nothing why they didn't do that? If he only got an eye exam recently it might not hurt for him to go back and again explain the problems he is having. If it wasn't that long ago they shouldn't charge him for a re exam. This time he should just come and ask about prisms with the doctor.

Probably not advisable for him or you to try ordering glasses with prism without knowing how much is needed.

eyescener 04 Nov 2016, 12:29

Wonder if anyone has any ideas on what to do here. My boyfriend age 29 has pretty strong astignatism correction in his glasses. With his glasses he sees pretty well except his right eye turns out at times. He says its most bothersome when trying to see signs or distant things. This was mentioned on his last 2 eye exams at different places. They offered no help. Wouldn't a prism help in this case in the problem eye? He is even afraid to drive. We dont have money or insurance for surgery. Also wonder if we could add a prism on our own. Any help or thoughts appreciated.

Mark 04 Nov 2016, 09:57

They allow you to place an order with high prescriptions however they then contact you to let you know what it actually costs, which is far higher than displayed.

Owlish 04 Nov 2016, 03:32

hyperaficionado I just did a check through at +14 and the price was excellent. Do they boost the price later or insist on high index lenses for high Rx glasses? Are they easy to work with or do unexpected complications crop up?

rafa 04 Nov 2016, 02:43


Thank you!

Have you tried them? Are they any good? Do they do regular lenses or myodiscs for that kind of prescription?


hyperaficionado 04 Nov 2016, 00:33


They go up to +/- 30 dpt!



rafa 03 Nov 2016, 04:18

Does anyone know of an online retailer that do lenses for prescriptions higher than -20?

Zenni only does to up to -20.

Likelenses 22 Oct 2016, 21:05

An interesting application of minus lenses for children.

30calcat 05 Oct 2016, 20:33

I got my Adlens variable focus glasses today and it turns out the explanation in the link I posted earlier is totally backwards. Slide it towards "-6D" and you see that it is actually a double-convex lens, which is of plus power +3. (Each side of the lens is about +1.5 I suppose). Slide it the other way and the high minus area of the "wave" lens overlaps the convex plus area to produce a net of up to -6.

In full minus mode, they are essentially -6 myodiscs with a plus carrier:

I need way more minus that what these glasses provide by themselves but they are still fun to play with. They are effective when piled behind glasses with old prescriptions that are a few diopters short of what I need.

30calcat 26 Sep 2016, 17:21

Great find Cactus! The same product seems to be sold as Adlens and the website has a nice interactive widget showing how the sliding lenses produce the range of powers:

Cactus Jack 25 Sep 2016, 19:04

I was shopping this evening and was looking at a display of OTC glasses. Included in the display was some glasses called Dial Vision glasses. They are adjustable from -6 D to +3 D. They were only US$20.00 so I bought a pair just to check them out.

They are pretty flimsy, but they work for Sphere ONLY in the above range. It is very interesting to watch the image size and sharpness change as you adjust them through their range. In a pinch, they are probably better than nothing.

They can't correct Astigmatism, but might be useful at the beginning stages of Inducing Myopia.

Google: Dial Vision if you want more information.


Crystal Veil 21 Sep 2016, 14:58


fascinating rotations. Thanks for posting!

til 21 Sep 2016, 12:21

Hi guys,

Does anyone have experience with aspherical lenses? I'm thinking about changing my everyday glasses from -3.50 (1.6 index) into -6 and would of course like to avoid questions. Same frame of course but still there is quite a bit of a change in outer appearance even to the 'untrained'.

Any input is greatly appreciated.

Owlish 03 Sep 2016, 23:14

Very interesting presentation of extreme lenses by an optical lab. After clicking on a lens be sure to hover on the pic to see it rotate.

JES 27 Aug 2016, 22:26

Gor my new glasses yesterday. I was very happy placing my order on the internet, where I could choose the thickest possible lens, index 1.50. I only have mild myopia -3.50, but I wear a large aviator frame to get as thick a lenses as possible. 20 years ago I had a similar, same size frame with a prescription of only -2,50. These old lenses were thicker than the new ones, even though they had a weaker prescription. Seems to me like even the thickest lenses on the market have become thinner..

GreginColo 25 Aug 2016, 21:07

Thanks Trent, interesting to watch a pair of high minus Rx glasses being made. In the days before the computer aided manufacturing, it must have been quite an art to make glasses, especially high RX ones.

Trent 24 Aug 2016, 10:19

Seiko Az 1,74 lenses -16.00 diopers

Inglasses2000 20 Aug 2016, 13:05

Hi Brian

You can email me at


Brian 20 Aug 2016, 12:04

Inglasses2000...sure give me your email address....

Edmund 20 Aug 2016, 09:55

I was similar to Brian where I started at 2 BI and now am at 8 BI.

Here are pics of my first 8 BI glasses:

Inglasses2000 20 Aug 2016, 06:30

Would it be possible to email me if I provide my address?

Brian 19 Aug 2016, 16:59

Inglasses2000....the times I've tried to log on I always seem to have issues with the forum...what would you like to know?

inglasses2000 19 Aug 2016, 16:10

Thank you for responding. Do you ever use the 'lenschat' site? would love to ask more about your situation

Brian 19 Aug 2016, 15:56

Was having double vision from time to time while reading and on the computer prior to getting prisms in my glasses. Had it slowly introduced and a gradual increase from 2 prisms in each eye around 7 years ago to 6 prisms in each eye now.

Inglasses2000 19 Aug 2016, 15:21

Nice lenses Brian. What issues were you experiencing prior to your prism add?

Brian 19 Aug 2016, 15:06

I have 6BI prism in each eye, here is what they look like up close, I uploaded a couple of images.

I first got prisms about 6 or 7 years ago.. Started out at 2BI, slowly increased to 5BI, was steady there for a few years and jumped up another prism this year.

Patrick B 19 Aug 2016, 04:27

Hi Sam 12744 -- Thanks for the input. I'd thought of getting the plano carriers at some point. Maybe my next pair. I wear contacts almost exclusively and probably have never got 100% used to looking straight ahead through the bowls when I'm wearing my glasses. I'm glad to hear that it can be done.

sam12744 18 Aug 2016, 17:48

I've only ever used plano or plus carriers, because I find it distracting to be able to see anything outside the bowls. My brain concentrates solely on what is in focus through the bowls, rather than on something blurry, but discernable as being less blurry than without any correction through the carriers. Mine are -30 in both lenses.

 18 Aug 2016, 08:58

Hi Sam 12744 -- Thanks for the information regarding myodisc prisims. I don't need prisim correction, but it's nice to know that it can be done. My prescription is -25/-26 with 25mm bowls and negative carriers. Have you ever used the negative carriers? I've always like them because the plus carriers are quite distracting and the cosmetic difference between the negative bowl and the plus carrier is so dramatic. What is your prescription?

 18 Aug 2016, 08:58

Hi Sam 12744 -- Thanks for the information regarding myodisc prisims. I don't need prisim correction, but it's nice to know that it can be done. My prescription is -25/-26 with 25mm bowls and negative carriers. Have you ever used the negative carriers? I've always like them because the plus carriers are quite distracting and the cosmetic difference between the negative bowl and the plus carrier is so dramatic. What is your prescription?

sam12744 17 Aug 2016, 17:44


I do not have a reading add and suspect that would be difficult to achieve in myodiscs. I can read happily in myodiscs, but I would slide them fractionally down the nose, if it were a problem. They are unblended with a plus carrier.

Doubledouble 11 Aug 2016, 20:36


Thank you for clarifying that. What do you do for reading? Do you need an add? Do the myodiscs have an add? Or do you have seperate glasses for reading? Also, last question, what type of myodiscs do you have?

sam12744 11 Aug 2016, 18:21

Patrick B and doubledouble,

I have myodiscs with 11 BO in each lens, so, yes, it can be done.

Cactus Jack 11 Aug 2016, 10:51


There is a company in New Jersey, USA called Rx-Safety Glasses. They offer some very high quality Clip-On Magnifiers (Readers) in different powers from +1.00 to about +5.00. They cost less than US$15.00 plus shipping. They will clip on most glasses and are very handy. I have several powers to help with various close work tasks. They flip-up out of your vision when need to look at something more distant.

Their web address is Look under Magnifying Products and then Clip-on Magnifiers. The come in two lens sizes. They may be on sale right now at 20% off.

Let me know if you have any trouble locating them.


Doubledouble 10 Aug 2016, 14:01

Thank you for sharing, Patrick.

Cactus Jack,

The pare where you staryed talking about add and magnifiers.

Patrick B 10 Aug 2016, 13:49

Hi Doubledouble -- You've certainly been the recipient of some excellent advice re your visual situation. My sphere prescription at -25/-26 is very close to yours without the prism and astigmatism corrections. That makes mine "easier" to fabricate than yours. Nevertheless, I also have problems with minification and generally wear contacts most of the time which provides me with a very good visual correction of about 20/30. I have had biconcave myodisc lenses for a long time and do like them both for their better cosmetic appearance and their ability to provide better acuity. The bowls are only 25mm which is typical for lenses of this sort and cannot accommodate a reading add like other eyeglasses which don't have the necessary height to accommodate multifocal lenses. I don't know if a prism correction can be ground into myodisc lenses but rather doubt it. Maybe that's why you have never been prescribed myodisc lenses. (I don't think an astigmatism correction poses that sort of problem.) I'd see if you can do what DS suggested and see if you can get contacts for the bulk of your prescription with the prism correction handled independently with glasses. As you probably know, a prism correction can't be handled by contact lenses so you will always be wearing glasses which shouldn't be a problem for you at this point. If your prescription has stabilized, there are other options such as IOLs. That, of course, is within the purview of a medical doctor and not a layman like myself. Let us know how things go at your next exam. I'm sure you would like to improve your visual acuity and need to find a specialist who thinks outside the box.

Cactus Jack 10 Aug 2016, 12:33


Which bit did your mean?

I am not particularly concerned about privacy except when it comes to sharing private contact information. I don't think that should be posted on a public forum. Over the years I have developed a procedure that seems to protect everyone's privacy. I never share contact information without specific requests and permission from all parties involved.


Doubledouble 10 Aug 2016, 09:50

Cactus Jack,

Thank you for sharing. Could you elaborate some more on the last bit. There is also a site that I found, we could chat on there if you want privacy.

Cactus Jack 10 Aug 2016, 09:10


Here is a link to a paper on the eye that you might find interesting and educational.


Cactus Jack 10 Aug 2016, 09:07


My latest prescription is:

OD Sphere-0.50, Cyl. -0.75 x 95, Prism 13.00 BO, Add +3.00 Trifocal

OS Sphere+0.75, Cyl. -1.00 x 80, Prism 13.00 BO, Add +3.00 Trifocal

but that does not really tell the whole story. I am almost 79 and have been dealing with double vision problems for the last 30 years. I have had cataract surgery that worked and eye muscle surgery that didn't. It is a long story, that I don't have time to relate, right now. Suffice to say, that when I am very tired, 13/13 BO is not nearly enough prism to keep images fused and i have to wear glasses with substantially more prism, but reduced VA or an eye patch.

I have some thoughts on your situation that might help some. I suspect that you have probably been able to avoid Physics, so far, in your educational pursuits. I will try to not get too deep into that, but I think it would be in your interest to study a little Optical Physics and Vision so you can be a knowledgeable active participant in your vision care.

Your prescription is very complex, but the idea offered by DS of using a combination of Glasses and Contacts could pay dividends in the VA department by increasing the image size on your Retina. The basic idea would be to wear very strong, Sphere ONLY, MINUS contacts and the rest of your prescription in your glasses. Because of Vertex Distance effects, CLs in the -16 to -18 diopter range could correct most of your Sphere. The key question is, could you wear the CLs and be able to deal with inserting and removing them.

It sounds like your Myopia increases are slowing. One of the things we don't know is the actual source of your Myopia. Myopia is caused by a mismatch between the Total PLUS power of your eye's lens system and the length of your eyeball from the back of the Crystalline Len to the Retina. Usually, Myopia is caused by excessive eyeball growth, but it can be caused by too much PLUS power in eye's lens system or a combination of both.

There are two types of Myopia. Axial or True Myopia that involves eyeball growth. It is considered permanent. Pseudo or False Myopia that is caused by failure of the Ciliary Muscles to fully relax to minimum PLUS power in the crystalline lens. Even fully relaxed Crystalline Lenses have a lot of PLUS. A person can have both types of Myopia, simultaneously, and the effects are additive. Pseudo Myopia is considered to be temporary, but temporary can be a long time.

Long term over correction can cause Pseudo Myopia and people with high Myopia often will choose lenses that over correct, in an attempt to improve VA.

You are on the right track with the Add, but it might be beneficial to minimize focusing effort to hopefully slow increases. Have you ever considered some Clip-on magnifiers (reading or computer glasses). They are inexpensive and available in powers from +1.00 to +5.00, if I remember right, from RxSafety Glasses. Let me know if you are interested.

That is enough for now. At some point, it might be useful for us to chat privately or on the phone. If you have any interest, please contact me at


Stingray 09 Aug 2016, 11:36

Is there a way to remove the sunglass tint from plastic lenses by using some homemade method?

Doubledouble 09 Aug 2016, 09:07

Cactus Jack,

Thank you for your response.

1. It was -26.25 and -22.25

2. 6 months

3. Yes.

4. I have been alerted ahout the possibility.

5. America

6. I am in graduate school for business.

I cannot believe you also have prisms. I have never meet anyone else who needs prisms before. What is your prescription?

Cactus Jack 08 Aug 2016, 15:36


Thank you. That is very helpful. I have taken the liberty of expanding it for easier reading.

OD: Sphere-26.50, Cyl. -6.00 x 120, Prism 17BO, 5BU, Add +2

OS: Sphere-22.75, Cyl. -5.50 x 85, Prism 17BO, 5BD, Add +2

I have a few more vision questions.

1. What was the Sphere correction in the prescription before this one?

2. What was the time interval between that prescription and the one above?

3. Based on your history, do you expect to need an increase in Sphere at your next exam?

4. Have you had any problems with Retinal Detachment or been alerted that it is a possibility.

Some other questions that help me know how to phrase my comments and offer suggestions.

5. Where do you live (country)?

6. May I ask your educational background?

Speaking from a purely optical standpoint, you have a very complex prescription. It may be very difficult to make “wearable” glasses using Myodisc lenses, particularly bi-concave Myodiscs.

There are many factors that affect Visual Acuity (VA) with corrective lenses. You have significant minification with your glasses. That means that the image details projected on your Retina are very small. While there are many millions of Rods and Cones (pixels) in the central part of the Retina, where you see detail, the signals from those Rods and Cones get compressed into about 1 million nerve fibers. If an image detail is too small, it may get lost in the compression process. But even before the image gets to your Retina, the light has to pass through the lenses in your glasses.

The “sweet” spot in a pure, sphere only, lens is the Optical Center (OC), where you get the least possible distortion and chromatic aberrations. The higher the lens power the smaller the “sweet” spot. Ideally, the Central Axis of Vision (CAV) will pass through the optical center and it is very important that the CAV impinge or strike the surface of the lens at a 90 degree Angle of Incidence (AI) (more about that in a moment). One of the things you learn with high power lenses is to not let your eyes stray very far from the “sweet” spot. That is particularly true with Myodiscs. When you introduce significant Astigmatism correction (Cylinder) that makes looking through the “sweet” spot even more important for the best VA. Then, when you introduce significant Prism into the prescription, it is very difficult to make sure that CAV passes through the OC of the lens and that the AI be as close to 90 degrees and possible.

If you need significant Prism correction as you do (I also have to wear significant BO prism) it is almost impossible mount the lens where you get the AI even close to 90 degrees and at the same time have the CAV pass thru the OC. The result is apparent induced cylinder which causes VA to decrease as Prism increases. Been there and done that, unfortunately, there is no tee shirt!

There may be some ways to improve your situation, but it is going to take some creative problem solving and few Eye Care Professionals have the time or inclination to be very creative. In general, they are trained to NOT be creative, but do what they have been taught. There are also limitations on what can be done without risk to your vision, which is a major consideration. The Oath of Hippocrates applies to all of this: “First, Do No Harm.”

Please remember that I am NOT an Eye Care Professional. My background is Engineering and Problem Solving. All I or any of us can really do, is offer some ideas and suggestions. Some suggestions will likely be impossible to implement. I try to limit my suggestions to what is practical in your situation.

If you feel you would like to discuss any of this privately, please feel free to contact me at

I note that DS has responded while I was writing this. DS is an Eye Care Professional and not as long winded as I am. Combining Contact Lenses and Glasses is one of the things I thought would be worth exploring, if you can wear CLs. Pay more attention to DS' suggestions than mine.


Doubledouble 08 Aug 2016, 15:10

Thank you for all the help and kind welcome so far. DS, thank you for the contact and glasses duo suggestion, I will ask my doctor about that.

DS 08 Aug 2016, 13:22


I hope you have found a good optician that has a real relationship with a lab. Your glasses will require better-than-average optics knowledge. You will be looking at myodiscs (whether "intentional" or ground to control weight and edge thickness) or double-concave designs. Double concave should provide a wider field of view.

One thing you may want to discuss with your doctor is the possibility of wearing contact lenses that contain the bulk of your prescription combined with a pair of glasses that can provide astigmatism and required prism correction. We don't have anywhere near the information to know if this is a possibility for you, but if this is a possibility I think you would enjoy the larger image size that is possible and full field of vision.

GreginColo  08 Aug 2016, 12:39

Double double. Thanks for the additional information you provided. That should help CJ or others better answer your questions. If Patrick B reads your post he might also be able to better answer about the benefits of myodisc glasses is that it allows the viewing area to be loser to your eye and thus clearer vision. Sharing a bit more about your vision history might also help gain some better answers and insights to your questions. I would presume the add for reading is a more recent development.

Doubledouble 08 Aug 2016, 10:31

Cactus Jack,

My current prescription is

OD: -26.5/-6/120/17/BO/5/BU/+2

OS: -22.75/-5.5/85/17/BO/5BD/+2


I am 24, and wear glasses only.

Cactus Jack 08 Aug 2016, 09:39


Welcome to Eyescene. Your questions about myodiscs are beyond my knowledge and experience, but we have a number of members that wear myodiscs and several members who are Eye Care Professionals (ECPs).

I believe it would be very helpful if you would supply your complete current prescription. Without that, your questions are not really answerable.


GreginColo 08 Aug 2016, 09:36

Hello double double. There are very knowledgable and helpful people on this site who make a very good effort to answer the questions you have posed regarding your vision and correction thereof. Since they are much more knowledgable in this area than me I will leave specific answers to them. But typically there is some additional information they might need to provide the best answer possible such as:

1) your most recent prescription.

2) your age

3) where you live

4) your occupation

5) whether you always wear glasses or sometimes contacts for vision correction

Getting some of this additional information posted may help others get a response for you more quickly

Also there were some recent discussions on the new glasses thread of two guys who wear myopia can glasses. So maybe there are some insights for you there as well. Hope this helps in some small way. Regards, Greg

Doubledouble 08 Aug 2016, 08:02

Hi, I have an eye doctor's appoimenr coming up, and have a question for before it. I require prisms in my glasses to correct my double vision, but I am also very nearsighted, and have some astigmatism. Also, thanks to the minimixation caused by my high RXed lenses and ny age I need an add to help me read small to medium sized print. I recently heard of myodiscs on wikipedia. I understand they are for people with higher myopia. Also considering the prisms, astigmatism and reading help, I am wondering if I am anle to get myodiscs? If I am are they a good choice? If nor what type of lenses do you guys recomend? I also juat heard of biconcave?

I know I said one question, but I have another I hope someone in this site can answer for me. How and why is it that my visual acuity goes down everytime I get a new prescription? I hinestly do not see why I wven hi to an eye doctor if yhat is the case. Can they not jusg give me some more (-) to better my acuity?

Thank you to anyone and everyone who tries to help me out.

Cactus Jack 06 Aug 2016, 08:17


"Cut In" is an optical phenomenon caused by the minification seen by others when they look at a person wearing minus lenses. The amount of minification is related to the minus power of the lens, the lens distance from the face (vertex distance), and the angle of view. It generally relates to the apparent inward displacement of the edge of the face as seen through the lenses and the actual edge of the face outside the lens. That is called "Cut In".

A similar effect occurs with a PLUS lens where the edge of the face appears to be displaced outward as a result of magnification. That is called "Cut Out". It is generally not as noticeable because the magnification of the face behind the lens moves the apparent edge of the face outward so that the edge of the face is not seen through the glasses.

Incidentally, prism correction can also cause "Cut In or Out" depending on where the base of the prism is located. The image displacement is AWAY from the Base (thick part) of the prism correction.

Wide or large lenses make the Cut In or Cut Out more noticeable.

If your MINUS prescription is high enough, you should be able to see the optical displacement of the edge of your face, through your lens, when you look in a mirror.

May I ask your complete prescription?

Also, please consider using a unique nickname so we can direct serious answers to you as having asked a serious vision or optical question seeking knowledge and understanding.


 06 Aug 2016, 00:24

What exactly is lens cut in? I am pretty nearsighted, double digits, and my lenses do not have any cut?

Cactus Jack 26 Jul 2016, 18:35


Everyone is different. As far as the lady you talked to, there is no way to speculate why she was wearing significantly different powers in the lenses of her glasses. It is a waste of time to try analyze her vision without actual knowledge of her situation. There are just too many possibilities.

These days, there are many things that can be done with refractive surgery. It is considered so safe that in some locales, Some eye surgeons even offer what is called, clear lens replacement where they remove a clear Crystalline Lens and install a multi-focal IOL to avoid "dreaded" bifocals or trifocals. Vanity is a very powerful force. The side benefit is that actual cataract surgery will never be necessary because it has already been done. It all depends on your needs, desires, what the surgeon is willing to do, and what you can afford.


Cara 26 Jul 2016, 16:42

So if it's not cataracts that's just the way it is then. So if you only need one eye doing they just leave the other one and if your shortsighted you have no choice to wear glasses because the prescription is so high? If your shortsighted and have cataracts done can you remain shortsighted with the same prescription?

Cactus Jack 26 Jul 2016, 13:43


It could have occurred naturally or she may be in the process of having cataract surgery.

The eyes actually develop and grow semi-independently and it is common for there to be a difference between their individual refractive powers. Usually it is less than 5 diopters difference, but nothing says it can't be. Sometimes, one eye needs PLUS correction and the other needs MINUS correction. The biggest problem caused by a big difference is the difference in the corrected image size on the Retinas.

When a person gets to the point where cataract surgery is needed on both eyes (also not absolutely mandatory for the two eyes to develop cataracts simultaneously), most eye surgeons prefer to wait some time between the two operations. As safe as modern cataract surgery is, it is still surgery and there is some small risk of infection and vision loss. When I had cataract surgery, the wait was two weeks. The shortest wait I have heard of was 1 week.

Most eye surgeons will offer a cataract patient the option of selecting their approximate prescription after surgery. Intra Ocular Lenses are available in a fairly broad power range (in 0.50 increments) and the eye dimensions, which are measured with an ultrasound probe, determine the actually power needed. You can have both about the same or as I selected an intentional difference called Mono Vision. The goal was to correct my Left eye to about 20/20 for distance and my Right eye to about -1.50. I still need glasses for the best vision because of astigmatism, but I can function and even legally drive, without my glasses.

Unless multi focal IOLs are used, it is very likely that bifocals, trifocals, or reading glasses will be needed after cataract surgery, depending on the final prescription.


Cara 26 Jul 2016, 12:22

I was talking to a lady today she was nearly 60 and wearing glasses for shortsightedness but only one of her lenses had cut in when was looking direct at me. Is -6.00 and -1.00 is that normal? or would of she had catract surgery so she has not much prescription in one eye?

How would she see without glasses still blind?

John S 13 Jul 2016, 14:46


I have always preferred a hard design over a soft design for a progressive lens. A Sola VIP was one of my favorites. Since I have to deal with the distortion anyway, I like it to come on strong, and give me a larger intermediate and reading area. Depending on the lenses and frame, the pantoscopic tilt can really make a big difference in the size and the distortion of the reading area.

Due to my lifestyle and accommodation problem, I grew up wearing an unusually strong add for my age. At 15, I could basically turn off my reading muscles at will, and need a +2 add.

When I got into my late 30s, I started wearing a +3.50 add full time in a PAL (I was wearing a +3.00 before that). It felt very natural to me. To use a pun, 20 years later and I have never looked back.

DS 13 Jul 2016, 09:49


The lenses in regular, lined multifocals will provide better overall vision at distance or at near in terms of field of view.

Progressives must compromise the field of view in order to accomplish their task. They provide an accurate correction only along a narrow corridor. The rest of the lens is a "blending" area that creates astigmatism. A much smaller area of the lens is actually useful for vision correction. With the lined versions, except right at the line all of the lens is useful for either distance OR near.

As the add increases, so does the distortion outside of that corridor. That is the price of the continuous range and no line.

There are many progressive lens designs, and they make different trade-offs between have larger useful distance or near areas, wider corridors and shorter transition zones for smaller frames and less head movement.

Thom 12 Jul 2016, 19:52

Is the optical quality of standard single vision or lined bi/trifocal lenses noticeably superior to progressive lenses?

I recently ordered a pair of glasses online and got regular bifocals instead of progressives as an inexpensive spare pair. While I understand the drawbacks, I am taken aback by the superior clarity of my distance vision, particularly at night.

As I am a mild hyperpope (+1.25 in each eye with very mild astigmatism, add +1.50) with still-good distance vision, I sometimes have difficulty at night. Sometimes I have to dip my head and look over my glasses with low light, to get better clarity of faraway signs. On the other hand, I get terrible headaches if I don't wear the glasses. This problem virtually disappears if I wear those bifocals.

inglasses 26 Jun 2016, 05:59

Hi John

How long have you worn myodiscs for?

John 22 Jun 2016, 13:35

Two years ago I paid £380 for a pair of 1.7 index blended myodisc lenses from Specsavers. I declined the offer of 1.9 index lenses that were £420. So I guess that the earlier post would be a similar price.

My prescription is -18 and -3.5 for cylinders.

gwgs 22 Jun 2016, 07:46

Interesting pic Trent, great find!

Dave 22 Jun 2016, 06:46

Yes, Trent, those are blended myodiscs with positive carriers. They probably cost her a pretty penny.

Trent 21 Jun 2016, 14:24

Blended myodisc I think

Cactus Jack 21 Jun 2016, 10:07




Carrie 21 Jun 2016, 09:30

Bit of a random question this.

Is it possible to have a prism prescription without sphere or cylinder also in the lenses?

No reason, just curious that's all.


Likelenses 01 Feb 2016, 16:38


I definitely like the rectangular ice cubes in a frame.

HighMyopic 01 Feb 2016, 15:47

30calcat can you PLEASE let me have those round framed glasses to wear fulltime? Or get me a pair just like those? I would love to wear those ALL the time!!

30calcat 01 Feb 2016, 14:00

Curious what other people here who like thick lenses think: Do you like rectangular lenses, or round lenses? I've been wearing these rectangula frames because I like the way the thick lenses have sharp corners at the edges:

Yesterday I got lenses in a pair of retro round frames:

They look a little thinner, but I can't decide which ones I like more. What do you all think?

jk45 09 Jan 2016, 09:14

found some more pics of Orbison's glasses. Perhaps around a +10 in his right eye and a +8 in the left? Some cylinder as well?

 09 Jan 2016, 09:09

Hey there,

I was recently visiting Wink TX and went to the Roy Orbison museum where the kind lady curator let me try on Roy Orbison's actual glasses. They were just about the thickest lenses I have ever seen which lead me to be curious as to what his rx might have been? The lenses were also definitely made of some kind of plastic and not glass and were from the 80s. The curator only knew that he was extremely farsighted and had a severe astigmatism in his right eye.

Just wondering what all you experts think his rx might have been just by looking at the lenses - found some pics below:

Puffin 18 Dec 2015, 09:19

I've got a floater in my right eye, noticed it about 2 years ago. Most of the time I don't notice it unless I'm looking for it. It does seem to be dissolving - getting steadily smaller - and moving to the right.

At first I was alarmed, then irritated, then forgot about it.

Feeling Powerless 16 Dec 2015, 21:19


Thank you for sharing your wife's positive experience. :-)

Feeling Less Powerless

Feeling Powerless 16 Dec 2015, 21:17

Cactus Jack

I'm grateful for the thoughtful response. Thank you.

Age 70, Before +5, After -1, Los Angeles, CA

The google search was informative in describing the procedure, etc. I'll continue searching, and reading.

I intend to move slowly in making any decision. At least, though, I'll be able to ask questions, and use terms the OP community is familiar with. :-)

Feeling Less Powerless

KL 13 Dec 2015, 10:34

Feeling Powerless - my better half had a vitrectomy about five years ago now. It wasn't exactly enjoyable, and she was definitely scared beforehand, but all went well and she hasn't had a floater since. She's ecstatic at the result, and I'm pretty much 100% certain she'd do it on the other side too if necessary.

Cactus Jack 13 Dec 2015, 09:37

Feeling Powerless,

I understand how annoying floaters can be. I have a few myself, but fortunately they don't seem to affect my overall vision very much. My most annoying one is a black dot that looks a bit like a fly near my face and my natural reaction is to try to swat it away. Fortunately, it seems to be affected by gravity and it will gradually drift down and out of my field of vision.

You have to be careful about forming opinions about things that occurred in the world of vision surgery 35 years or even 5 years ago. I really have little knowledge about procedures to remove floaters, but I did a Google search on "vitrectomy floaters" (without the ") with lots of results. You may have difficulty separating the wheat from the chaff.

I wish I could offer more information, but you didn't give me much to go on. Things like your age, where you live, and your prescription before and after your cataract surgery. I think you should get a 2nd opinion from a different Ophthalmologist and perhaps an Ophthalmologist who specializes in problem with the Vitreous humor. The important thing to remember when selecting an ECP is that they may advocate a procedure they learned rears ago and have not kept up. Also, you may not want to be a guinea pig for the very latest techniques, unless there is significant proof that it works.


Feeling Powerless 12 Dec 2015, 23:41

Cactus Jack,

Had Cataract surgery in August, and September. All went well, mostly.

Now I have large active floaters in one eye. They move with my eye when I'm reading which drives me crazy, and they sometimes 'fog' up my distance vision as well. I'm told by my physician that it takes the brain a good six months to adapt to them, so he scheduled an office visit in six months. Seemed very reasonable.

I've heard there is an operation to remove them. However, one guy told me his dad had the operation in the 80's when it was a new procedure, and regretted it for the rest of his life.

Would you happen to know anything about it?

If you're able to shed some light on it I'll be forever grateful

Likelenses 12 Dec 2015, 22:02

Some pretty heady info here.

Likelenses 12 Dec 2015, 21:28

Great technical info.

astigmaphile 12 Dec 2015, 14:53


When I was young enough to have good hearing, I could hear the sweep generator in what would now be antique TVs. The frequency was 15.75 kiloherts.

Melyssa 12 Dec 2015, 09:38

Thank you for the response, Cactus Jack. I remember "fine tuning" an old TV -- it was in the living room, and while I was at the kitchen table doing homework (yuck) or playing a game (yay), I could hear the horizontal hold go off. I would say, "Not again!" and go in and fix it, as my parents marveled at how I could tell it was off base.

Cactus Jack 11 Dec 2015, 18:34


Not much to remember. Before the exam, just ask the examiner if they will let you "fine tune" the axis on your cylinder correction. Most will.

At the appropriate point they will need to guide your hand to the Axis adjustment knob and you can rotate the knob back and forth a bit, for the clearest image. It usually does not take much rotation.

It is sort of like "fine tuning" an old TV.


sam12744 11 Dec 2015, 17:33


Try, under 'special making'.

High Myopic 10 Dec 2015, 15:26

30CalCat, if you still have the two pairs of glasses that are too distorted from the other lab, can you let me have them to wear? I collect eyeglasses and like to wear very strong glasses. You can mail them to my house so I can use them and enjoy them.

30calcat 10 Dec 2015, 15:00

So I had to go on a quest again recently to find a lab that still knows how to do thick lenses. 3 years ago I was still able to get good lenses from my local optometrist but it appears they either switched labs or the lab quit doing them. Either way, the last two pairs I got had heavily beveled edges, and they claimed "that's just the way they come out of the machine." To add to the injury, one pair used a material with so much distortion they are unwearable.

I remember getting a fairly useable pair from Walmart before. It was over 10 years ago, but I gave it a try, plus at their prices it is not a big gamble at all. When the lenses came back I was thrilled! They did the lenses exactly as I wanted - no roll, bevel, and polish, and the material used offers the best optics I have ever had in a pair of glasses. Distortion and chromic abberation are virtually nonexistant, even with the front curve dished in for a biconcave lens. Walmart's labs have obviously made some huge improvements! It literally brightens my day every morning to put on these pair of glasses and be able to see so well.

Pictures of the beautiful lenses for you all to enjoy as well:

astigmaphile 09 Dec 2015, 17:10

Cactus Jack,

Thank you for the explanation. I misunderstood you. You meant understanding the optical principles involved.

Melyssa 09 Dec 2015, 13:51

Cactus Jack,

Thank you for the accomplishment compliment. It did take me lots of hard work and lots of study time to get my degrees, sacrificing my social life to finish my necessary education at age 32, just 4 years after going back for computer science. (Bookkeeping wasn't going to earn the big bucks.)

Maybe it was my drop-temples and cat's-eyes that made me such a genius. :)

I found out about astigmatism the hard way, a month before my 8th birthday. I should read up on the "fine tuning" of cylinder axis before next year's eye exam, because information overload probably will keep it out of my memory before then.

ThickL 09 Dec 2015, 07:57


Is there a place where they create thick lenses with small prescriptions? (Around -3)..



Cactus Jack 09 Dec 2015, 07:01


Trying to understand how lenses work to correct astigmatism and Myopia or Hyperopia, for that matter, messes with some people's mind. Trying to explain it in easy-to-understand terns messes with mine. I have done lots of basic optics and GOC calculations, but occasionally I get confused when trying to develop a mental picture of all the various lenses and effects involved, particularly Vertex Distance effects.

Speaking of mental things, WOW!. Congratulations on your accomplishments. I know it took lots of hard work and study to achieve what you have. Imagine how much harder it would have been, without vision correction.

Unless you understand how lenses and vision correction works, it is very hard to get your mind around the fact that two (apparently) very different prescriptions, can yield one pair of glasses and both be correct.

With that much Astigmatism, it is pretty easy to tell when the axis is not quite right. Have you read my suggestion on how to "fine tune" the cylinder axis during an eye exam? It mostly benefits people with low cylinder requirements.


Melyssa 09 Dec 2015, 05:48

My astigmatic cylinder is +3.00. I am a two-time, two-time, Magna Cum Laude college graduate, I have been a computer programmer for 25 years, and I root for the Philadelphia sports teams. So yes, my mind is definitely screwed up. :)

Cactus Jack 08 Dec 2015, 22:56

OOPS! It is getting late here and I should have addressed the two posts below to Astigmaphile. Sorry about that. It also would have helped if I had put on my glasses instead of enlarging the text.


Cactus Jack 08 Dec 2015, 22:54


I should have mentioned that trying to understand how some prescriptions work can mess with your mind. Plus Cylinder is one of them. Another is to keep in mind that Glasses or Contacts NEUTRALIZE or CANCEL OUT existing refractive errors. A person who has too much PLUS power in his eyes needs MINUS correction and a person who does not have enough PLUS power in his eyes needs some more PLUS.

As I mentioned in other posts, Astigmatism is typically caused by uneven curvature of the front surface of the Cornea. The Cornea typically has a lot of PLUS power, typically +30 to +40 diopters. If there is some Astigmatism, the Cornea may be say +40 in the long axis and +41 in the short axis. If you are doing a refraction with a + Phoropter, you would need to wind up +1.00 Cylinder in the long axis to balance the two powers. If you were using a -Cylinder Phropter, you would need -1.00 in the short axis to balance the two powers. In both instances when you got to the Sphere part of the exam, the patient would select the appropriate Sphere lens power to see the 20/20 line clearly, even though the selected Sphere lens would be different depending on which type Cylinder lens was used for refraction and the specified Axis would be different. The end result with either type Phropter should hopefully provide comfortable vision.

May I ask your prescription?


Cactus Jack 08 Dec 2015, 22:30


Your prescription may have been written with + Cylinder, but I can almost guarantee that the lens maker converted the + Cylinder to - Cylinder and made the glasses. The conversion procedure is very straight forward and it works in both directions.

1. Algebraically add the Cylinder to the Sphere

2. Add or subtract 90 degrees from the Axis angle so that the result is between 0 and 180 degrees.

3. Change the sign on the Cylinder.

For example lets say that your prescription is as follows:

OD Sphere -3.50, Cylinder +1.00, Axis 75

OS Sphere -3.25, Cylinder +0.75, Axis 85

The conversion to - Cylinder

OD Sphere -2.50, Cylinder -1.00, Axis 165

OS Sphere -2.50, Cylinder -0.75, Axis 175

Typically, MDs use + Cylinder Phropters or Trial lenses and ODs use - Cylinder Phropters or Trial lenses. It does not really matter because the end result is optically identical.

Occasionally, there will be a panicked post from a person who has been getting eye exams from an ECP that uses - Cylinder and then goes to an ECP that uses + Cylinder. They think they have had a massive change in their prescription when in reality, there has been little change.

I read somewhere why MDs tend to use + Cylinder and ODs use - Cylinder. I seem to recall that refraction technique was easier to teach using + Cylinder, but I am not sure. The use of - Cylinder for lens making is because typically, material is being ground away from the middle of the blank to generate a - lens. To make a + lens, you have to grind away a little material from the center of the blank and a lot from the edges.


astigmaphile 08 Dec 2015, 16:49

Cactus Jack,

Why would plus cylinder screw up your mind? I wear plus cylinder, so I am curiuos.

Cactus Jack 08 Dec 2015, 13:26


I apologize for not being clear. -1.00 in sphere and -1.00 in Cylinder have the same refractive power, but the Cylinder lens refractive power varies depending on the axis. In the Cylinder lens, the long axis has 0.00 refractive power and the -1.00 power only occurs on the short axis which is 90 degrees to the long axis. By tradition Ophthalmic Cylinder lenses are specified by the direction of the long axis. Looking at the patient, the 0 or 180 axis is Horizontal. The numbers increase in a counter clockwise direction with 90 degrees being vertical. Traditionally, Cylinder axis are only specified from 0 to 180 degrees.

In the case of a sphere lens if you hold the lens up in front of you and rotate it through 360 degrees, you will see that its effects on what you see through the lens does not change as you rotate the lens. It has -1.00 per in all axes

If you do that with a cylinder lens you will note that the image is not altered on the long axis, but is substantially changed in the short axis which is 90 degrees to the long axis. The Cylinder lens has 0.00 power on the long axis and -1.00 power in the short axis and its refractive power varies with the axis, which makes the images look distorted

If you combine a Sphere and a Cylinder lens into a glasses lens the power of the combined lens would be -1.00 on the long axis of the Cylinder and -2.00 in the short axis of the lens.

The Sphere part of the lens corrects the Refractive error caused by the mismatch between the power of the eye's lens system and the length of the eyeball. The Cylinder part of the lens corrects the uneven curvature of the Cornea (Astigmatism). Astigmatism screws up the image delivered to the retina, but he brain corrects it the best it can. Unfortunately, there is no way to correct astigmatism except wth external lenses or reshaping the cornea.

What will screw up YOUR mind is a prescription with PLUS Cylinder. We will save that explanation for another day.


Stingray 08 Dec 2015, 12:42

Cactus Jack: I think you missed my point. What I was asking was what would the equivalent sphere power be to a cylinder power? For example: would a -.25 cylinder be the same power as a -1.00 sphere? Would a -1.75 cylinder have the same power as say a -3.00 sphere or whatever? I once heard from an optician that the real power of your glasses was the sphere and the cylinder added together. Just wondering. No big deal.

Cactus Jack 06 Dec 2015, 17:22


You could do the same thing in glasses by adding 1/2 the cylinder power to the Sphere power, but what would be the point when you can achieve the best correction by just making the glasses with the correct cylinder and axis.

There is a post on the Astigmatism thread asking why there is a difference between VA with glasses and contacts. Even a Toric lens is a compromise whereas correctly prescribed and made glasses are not.


Cactus Jack 06 Dec 2015, 17:16


Sphere power and Cylinder Power are really the same thing, The difference is in the physical shape of the lens.

A Spherical lense is like a slice off the side of a clear glass (or plastic) ball. Its ability to bend a light ray is the same in all axis. It does not matter how a Sphere glasses lens is mounted in an eyeglass frame. It is easy to image a PLUS lens this was, but It is harder to imagine a minus lens in this way. Think of a minus lens as having had a plus lens carved out of a flat lens blank and you will get the idea.

The actual power of a Sphere lens is the difference in curvature of the back and front surface of the lens

A Cylinder Len is a little harder to picture, but imagine a round clear glass or plastic rod. You could slice the rod into disks or you could cut off a slice lengthwise and you would have a rod that is curved on one side and flat on the other. That becomes a cylinder lens. If you were to measure the curvature if both sides of the lens in the long (axis) direction they would both be 0.00. Therefore, the cylinder power in that direction would 0.00. However, if you were to measure the curvature around the curved side, it would be PLUS something, but the flat side in the same direction would be 0.00. The result is a PLUS cylinder lens. For Ophthalmic purposes the long axis of the lens is the "axis" in an optical prescription. MINUS cylinder would occur if you scooped out enough of the flat side of the cylinder lens to overcome the PLUS power of the front side.

Cylinder can be prescribed as either PLUS Cylinder (MDs) or MINUS Cylinder (ODs) with consequent effects on the Sphere and the Axis. There is a simple formula to translate from one to the other and the optical results in the glasses are identical. Lens makers convert from PLUS Cylinder to MINUS Cylinder and make the glasses. The reason for this is that lenses are ground by removing material from the lens blank.

Sometimes Cylinder power is compromised in Contact Lenses to avoid fitting Toric lenses. The way this is done is to Add 1/2 the Cylinder Power to the Sphere Lens prescription.

Hope this helps.


Stingray 06 Dec 2015, 14:32

I have a question about cylinder lenses for astigmatism that I hope someone can provide an answer for. What would be the minus sphere equivalent of say a minus .25 of cylinder? Can they be compared to each other. If one has a cylinder correction of -1.75, what would be the equivalent minus sphere correction? Like is a -1.75 cylinder the same for example as a minus 3.00 or more or less sphere?

 01 Dec 2015, 16:38

I was talking to a middle aged women maybe late 50s that was wearing glasses and noticed she had one lens with not much correction maybe none and the other lens she had cut in when I was looking straight at her. How nearsighted would that be? I woundered if she was always shortsighted in just one eye or had eye surgery on the other? Would glasses be uncomfortable to wear?

Likelenses 22 Nov 2015, 16:18

I wasn't sure where to post this,but this seemed most appropriate.

With thanksgiving coming up this week Cheryl and I are traveling out of town to visit her mother,and family.I have not met them,but Cheryl has told me that her mom has all of her glasses,and prescriptions since her first pair.

She has said that she had several large increases in prescription when she was young,so I hope to see her visual history.

Her mom knows that she had a small increase in her myopia,and now wear bifocals as of last spring,but Cheryl has not told her about the myodiscs that we had made up for fun.

She said that she may walk into moms house wearing the myos,but will make that decision last minute.

gerry 11 Nov 2015, 05:53

Why do we guys love to date ladies wearing high RX glasses, most guys prefer ladies with a high -rx i prefer a high plus rx. also why do some ladies object when you tell them they have nice frames, are they shy about their glasses. I must admit i,m shy to admit i find ladies with high plus rx very attractive, would love to b in a serious relationship if it were possible. I appreciate this is not a dating site. To all you lovely glasses wearing ladies have fun take good care xx

dave 23 Oct 2015, 04:52

hello,do you know any online retailers that do contacts above +20 as I cant seem to find any ,cheers

Melyssa 22 Oct 2015, 04:47


If she tried on a monocle she would probably keep the other eye closed to keep the monocle in place, as Sgt. Schultz did when he wore one in an episode.

If Cheryl does consent to wear one, she will also need a riding crop (like Klink), along with a purple top hat, a tuxedo, and an advanced-weapon umbrella (like the Penguin). LOL

Astra 22 Oct 2015, 01:33

Re: antonio 21 Oct 2015, 10:26

Typical MR8 or MR7 lenses can act as a UV blocker capable of blocking 80% of the UVA-UVB that is quite suitable for winter season. With monocles the covered area is too small. Apart from correction I would like to have my eyes partially covered by the plastic frame and the MR lenses . The world inside the MR8 or MR7 would be beautiful.

Astra 22 Oct 2015, 01:22

Re: Likelenses 21 Oct 2015, 16:19

you can simply put one of her own lens of her glasses turned 90 degrees, placing in front of her eye (right or left) . it is not exactly a monocle but can give you the monocle sensation, and if you can explain you are not going to hurt her eyes , Cheryl can probably appreciate the fun for that.

Likelenses 21 Oct 2015, 16:19


Yep, that is the case with Cheryl,or even myself.

I like to push her buttons though to see what reaction I will get.She is really funny,and the things that come out of her mouth crack me up.

I think that a monocle on her would be interesting,as when she takes her glasses off ,there is no squinting,just an empty look in those unfocused eyes.I wonder if only the the monocleed eye would perk up,and the other have the empty look,or if the other eye would squint out or sympathy.

Melyssa 21 Oct 2015, 12:02

I would not (and I cannot) wear a monocle either, and not because Colonel Klink of "Hogan's Heroes" and the Penguin of "Batman" wore them. If I did, the other eye would say, "I see nothing! Nothing!"

antonio 21 Oct 2015, 10:26

Hi Astra,

so nice to see a message of you :-)

yes, monocles aren´t very practical if one need our strength of glasses, right ? .-)

cu best regards, antonio

Astra 21 Oct 2015, 01:47

Re: Likelenses 19 Oct 2015, 00:55

monocles are probably not comfortable to wear , and unable to cover both eyes.

Astra 21 Oct 2015, 01:47

Re: Likelenses 19 Oct 2015, 00:55

monocles are probably not comfortable to wear , and unable to cover both eyes.

ric 21 Oct 2015, 01:10

In the blended lenticular lenses, the transition between the lens zone where is the prescription and the carrier lense, is soft blended, so are less notticeable. In the regular ones, the edge of the prescription zone, is clearly notticeable. Next time i would like to get the blended lenticulars better tan my current high idex regular lenses.

MKX 20 Oct 2015, 16:44

Hi, everybody!

Can someone explain to me the difference between blended and non-blended myodiscs? And how to distinguish or identify each one of these lenses?

Thanks in advance.

Aubrac 19 Oct 2015, 01:35


My wife has a plus prescription with 3 degrees base out prism. Looking at her lenses from the side you can see what appear to be minus power rings but are the prism correction.

I saw a young lady a while age with the popular large black geek frames. I thought they were plano but noticed some slant probably from cylinder correction, and when she sat down there appeared to be power rings at the bottom of the lens but which may have been due to base down prisms.

Likelenses 19 Oct 2015, 00:55

Monocles are making a comeback.

I showed Cheryl this article,and her response was," if you think that I am going to wear one of those,you are nuts ".

Likelenses 15 Oct 2015, 17:13


Cheryl wanted,and I concurred the thickest possible look,and to keep the cost down went for the myos without her add included.

When she wears them,it is mostly for fun,and if she can not discern something close she loves asking me to read it for her.When she wears the myos she has fun playing the dependent role.

She has become very adventuresome about glasses.Recently I told her about GOC,and now she has been talking about perhaps trying that.

gwgs 15 Oct 2015, 09:40

Thanks for the response guys - this was my initial thought but having never seen lenticulars before I didn't know what they looked like.

These sorts of sightings seem to happen so rarely in London that I've only ever seen myodiscs once, and now lenticulars once in about 15 years!! I can only hope that I bump into this extreme hottie again in the local area as she was certainly memorable (daydream time).

Soundmanpt 15 Oct 2015, 08:17


Just curious, when you Cheryl and you ordered her her lenses for her vintage glasses and was given the choice of a plus or minus carrier for her myodisc's she chose to get the minus carrier based on looks. But since she has a need for an add which I don't believe is all that strong wouldn't getting the plus carrier worked well for her add?

thebrit 15 Oct 2015, 02:00

GWG......As has been said by G for E it is almost certain that the lady wearing plus prescription glasses with very thick outer edges will have had some significant Base Out prism in her prescription hence the thick outer edges.

Regrettably it is not possible with a plus prescription & base out prism to get the outer edges thinner. However, I think it is easier to thin the edges more if it is a minus prescription with base out prism by going the myodisc route?

Likelenses 14 Oct 2015, 23:08


I am thinking that she was wearing the plus equivalent of myodiscs,which I believe are called lenticulers..

When we ordered Cheryl's myos she had to choose the type of carrier,plus,or minus.They both have their advantages,and drawbacks.The important part of the lense of course is the bowl.

Cheryl likes the minus carrier because it is more becoming to match the hi minus bowl,although the edge,and actual lense thickness are about the same.Her bowl is flat on the front,and REALLY scooped out on the backside,giving it an incredible deep look.

Perhaps the young lady you saw wanted the lense thickness ,and the bowl to be somewhat the same.

glassesforeveryone 14 Oct 2015, 02:25

Hey Plus Tony,

Glad you like your new glasses. Welcome to the club!

glassesforeveryone 14 Oct 2015, 02:22

gwgs, the most likely reason would be that she has a significant amount of base out prism in her glasses due to strabismus.

I have plus lenses and base out prism, so my lenses are thicker on the outside than in the middle.... nothing like you describe here, but the principle is the same.

gwgs 14 Oct 2015, 01:40

I've copied this from the sightings post as I realised I may get more of a response here - this has had me baffled for several days;

An amazing sighting at the weekend. I was in line waiting at the cashpoint when I saw a stunning blonde girl probably in her mid to late 20's standing in the next line. She was tall and skinny and I was immediately surprised and perplexed by her glasses.

Her lenses appeared to be of a rather strong plus prescription as her eyes were very magnified, but the thing that threw me was I could see the polished edges of her lenses protuding out of the edge of the frames which should indicate a strong minus prescription!! She was standing sideways to me but obviously I wasn't being that unsubtle in admiring her as she may have noticed I was looking at her as she turned her head to look at me, and smiled. Her magnified lenses refracted the morning sunlight off her thick lenses.

To those that know a lot more about lenses than I do, can they please explain this sighting, as plus lenses obviously increase in thickness in the middle of the frame, not the outside, so how were her lenses thick at the outside edge?

Plus Tony 03 Oct 2015, 06:17

just realised I got my eyes wrong way round in earlier post not that it makes a difference (on paper anyway). Left is +1. Right is +2.

Plus Tony 03 Oct 2015, 02:49

I am a new wearer with R +1.00, L +2.00 and I immediately opted for full time wear. I'm very happy about my quality of vision and was amazed at how quickly everything near and far snapped into focus. Admittedly after the initial excitement wore off I had to admit that very far distant objects were a little blurry but now they are coming back I'm even more happy because I can tell that the glasses are doing their job.

I absolutely love the slight magnifying effect of the lenses but my partner says my right lens looks odd. She says I should get a thinner lens for that eye so they match in terms of magnification. Personally I think the difference is barely perceptible but I want her to support my decision to go full time and would appreciate the thoughts of more experienced hyperopes and the experts here about what to do.

bracesfan 28 Sep 2015, 23:25

Not myodiscs but regular lenticulars are made from -8 up.

bracesfan 28 Sep 2015, 23:25

Not myodiscs but regular lenticulars are made from -8 up.

specs4ever 28 Sep 2015, 07:54

Charlie, in the past with regular plastic lenses I have had myodiscs made up as low as -10D. But they normally started around -15 or up. Now, with the higher index lenses myodiscs are not normally used until around -20D although I have seen some as low as -18D. Hope that helps.

charlie 28 Sep 2015, 02:02

hi,i was wondering if any of you guys can answer my a couple of questions,1 at what rx do minus lenses become myodisc lenses ,2 if I have myos in a low index lens will they still be myos in a high index lens,thanks

Iamhacked 13 Sep 2015, 00:09

Cactus Jack,

I don't think it is rotating too much because my vision doesn't change every time I blink. However I do occasionally get better vision when I close my eyelids tight for a moment. So you might be right.

Cactus Jack 12 Sep 2015, 20:55


Your astigmatism is a very significant element in your prescription. 2 degrees axis difference is not very significant even with your cylinder. I doubt the blurriness has any thing to do with the contact lens solution. If you recall, my earlier post where I said the Toric Contacts are very hard to fit because it is sometimes very hard to keep the axis correctly oriented on your Cornea. The contacts may be rotating as you blink. If the axis of the cylinder correction does not match the axis of your astigmatism very closely, your vision will be very blurry.. If your contacts are rotating, you vision with change as you blink. Occasionally, your vision will be sharp and clear, but mostly blurry the rest of the time.

I don't have as much cylinder correction as you do, I tried wearing toric contacts as part os a research program, but could not wear them because they rotated and moved around out of alignment. The optometrist was very experienced fitting Toric CLs and he tried a number of tricks to try to stabilizing on my cornea. Nothing worked and I had to drop out of the research program.


Iamhacked 12 Sep 2015, 10:59

Oops, forgot to add that I have a follow up appointment on Monday. What should I tell the optician?

Iamhacked 12 Sep 2015, 10:58

Cactus Jack,

Thank you for your advice. I went to a local optician and got fitted with Air Optix for Astigmatism after doing some tests on the machine. I don't know my test results, but this one has a BC of 8.7 and a DIA of 14.5 and it fits pretty good.

My glasses prescription was:

OD SPH -1.00 CYL -2.25 AXIS 008

OS SPH -2.25 CYL -2.00 AXIS 180

The contact prescription seemed to be a pretty direct translation of the glasses prescription. except for my left eye, cylinder was -1.75 (because it's in 0.50D increments) and for my right eye the axis was 10 instead of 8.

My vision with the contacts is pretty good except the astigmatism. I'm a 19 year old student and text can get quite blurry and fuzzy during class. I'm not sure if it's because of the wrong astigmatism axis, or my contacts solution.

Cactus Jack 06 Sep 2015, 16:01


Maybe, but I strongly suggest that you should not try it without an Eye Care Professonal's (ECP) help, particularly for a first fitting of Toric Contact Lenses.

With your significant Cylinder, you will need what are called Toric contacts. Toric Contact Lenses are notoriously hard to fit and very hard to keep in place on your Corneas. Contacts need to move around when you blink and unless the Cylinder and Axis (which always go together) part of your prescription is correctly positioned on your cornea, the resulting vision is worse than your vision without glasses. Also, your vision can change every time you blink.

If you can be successfully fitted with Toric Contacts, you will have the Brand, Diameter, Base Curve, and Prescription to search for Toric Contacts with more Sphere correction if that is what you want.

We may be able to offer some alternative suggestions, but we need more information.

1. Your complete Prescription?

2. Your age?

3. Your Occupation?

4. Where you live?

5. Why do you want Contacts with a stronger prescription?

If you prefer, you may contact me privately at


Iamhacked 06 Sep 2015, 14:23

What kind of contacts can I get at -2.00 and -2.25 cylinder? My prescription is -1.00 and -2.25. Can I get daily disposable soft contacts? I've never tried contacts before.

Cactus Jack 02 Sep 2015, 08:07


I suggest CR-39 or similar low Index lenses. They will be a little thicker than Polycarbonate. CR-39 has the least Chromatic Aberration (Abbe) of any plastic lens material and the best optical quality. All lenses have some Chromatic Aberration because their job is to bend the direction of light rays, but the amount of bending varies with the color of the light. Normally, you don't notice the Aberration, but it does make your vision with even a perfect prescription just a tiny bit fuzzy. Also, the higher the prescription the more noticeable the Aberration. There are ways to eliminate the Chromatic Aberration but they are complex and expensive. That is why high quality photographic lenses are big, expensive and contain multiple lenses.

Anyone who thinks someone who has a prescription of Sphere -1.25, Cylinder -0.75 doesn't really need glasses. is stupid and does not understand Vision or Optics. The -1.25 means that anything beyond 80 cm or 31 inches is increasingly blurry and the 0-.75 cylinder makes it even worse. Astigmatism, corrected by Cylinder affects vision at all distances and makes small text hard to read.

Remember, you don't wear glasses for the benefit of others and you DO NOT require their approval or permission to see well. If they think you don't need glasses, suggest they try on some +1.75 or +2.00 reading glasses to get an idea of what your vision is like without your glasses. The +1.75 or +2.00 is a Sphere approximation of your vision without glasses.

IF you just want some stronger or thicker glasses, we can tell you how to do that. May I ask your age?


Soundmanpt 02 Sep 2015, 07:53


Aside from what you already have done by ordering your lenses be made in 1.50 lens thickness and the possibility of finding a bigger frame which like "Millhouse " said should cause your edge thickness to be a bit more noticeable. Also a rimless or semi-rimless frame will expose the edges of your lenses much better as well. Actually I think your being far more concerned than you need be about your lenses not looking very strong. If you look your sure to find that most everyone glasses look about the same as yours. Most with much higher prescriptions often go with hi index lenses so they don't look as thick or they wear contacts. Your prescription isn't very strong but as said your glasses make a big difference to you. But between your distance and your astigmatisms you should be more comfortable wearing your glasses full time. There are people with a weaker prescription than you that wear their glasses full time. Also remember that 99.9% of people have no idea about judging how strong ones glasses are. They only notice the frames on someone. As i'm sure you already know, anyone trying your glasses on can easily see that you need to be wearing them and they probably feel strong to them. So don't allow others to cause you not to wear your glasses. If your glasses look nice on you and fit your face well that is all they are going to really notice and your lenses probably look very nice in your frames.

Melyssa 02 Sep 2015, 07:44


I agree with what Millhouse and Specs4ever said. Most glasses in my ab-fab collection are very large, and all pairs have CR39 lenses in them. Granted, at -9.00 my prescription is a lot stronger than yours, so my lenses are quite thick on their own.

specs4ever 02 Sep 2015, 07:38

You are correct with the thoughts of a larger than normal frame size, but I would suggest regular CR39 plastic with what they used to call safety lens thickness, where the center thickness is 3.0mm instead of the normal 2.2mm used in the USA.

Millhouse 02 Sep 2015, 05:02

- Guest,

Ask for a standard polycarbonate lens and choose a larger wider frame style , the wider/ deeper the lens, the thicker they will appear from a side view or with "Cut in" from a front view.

As long as your ok with the idea of outsize frame designs.

This depends on your own looks, sense of style and inner confidence.

Others here will no doubt also have suggestions to help you.

guest 02 Sep 2015, 02:54

I have a patheticly low prescription, sph -1.25 cyl-0.75 both eyes, my glasses look like plain glass, so thin and I dont like wearing them since they dont look like they are necessary! (they do make a huge difference to my vision)

Where can I get lenses made that come out with a much thicker edge thickness compared to the nornal 1.50 lens which are so thin with such a prescription? Im sure Id like wearing them more if they looked more agressive!


guest 02 Sep 2015, 02:54

I have a patheticly low prescription, sph -1.25 cyl-0.75 both eyes, my glasses look like plain glass, so thin and I dont like wearing them since they dont look like they are necessary! (they do make a huge difference to my vision)

Where can I get lenses made that come out with a much thicker edge thickness compared to the nornal 1.50 lens which are so thin with such a prescription? Im sure Id like wearing them more if they looked more agressive!


Mo tard 21 Aug 2015, 19:38

This category seems closest to this post. The screw came out of the right side arm on my -9.25 glasses today. When that happened they come off my face and hit the concrete floor chipping the right lens in lower outer corner on the inner edge as outer edge was protected by the frame. I'm going to attempt to cosmetic repair it. I know the chip repair area will not be optically correct but will cosmetically disappear I'm hoping. I'll let you know the results after the weekend when I can procure supplies needed. Maybe put together a write up procedure and maybe photos to go along if I can post them some where here

Andrew 18 Aug 2015, 00:15

When I run out of prescription contact lenses before my regular supply arrives, I use the Internet. I've never been asked for my prescription, which is just as well, as I don't have it, but I can get the correct lenses by reading what the labels say on the boxes.

Rimpopper 17 Aug 2015, 21:06

Any ideas about where to get contacts without having to present a prescription? I need a pair of plus lenses to continue with GOC.

Cactus Jack 16 Aug 2015, 19:57


A bit more information is needed to calculate the difference in lens thickness in plus lenses of the same prescription and size between Indexes of 1.50 and 1.57. The 1.50 will be a little thicker in the center of the lens, but probably not very much. May I suggest checking out (Google):

The have a very handy lens thickness calculator on line. Give it a try and tell us what you discover.


Stingray 16 Aug 2015, 13:21

How much of a difference is there between 1.50 and 1.57 index lenses in regards to thickness on a plus prescription?

30calcat 14 Jul 2015, 15:56

Likelenses 13 Jul 2015, 22:41


Are those your glasses that you posted a photo of. If so, can you post a few more photos of them at some different angles.

Are you A guy,or a girl?

30calcat 13 Jul 2015, 13:25

Thanks for the info Soundman. I admit I've never tried talking to an optician about drilled rimless and I just assumed no one was willing to take time to try to make it work.

Patrick, if I was sensitive about my thick lenses I would wear contacts or thick plastic frames that hide the lenses. I like the look of a strong thick lens, so when people comment it could be that they share my interest. I wonder if anyone has ever connected with another OO this way. However, if I were making a comment on someone else's glasses, I would try to be more tactful and start with something like "I really like your glasses."

Soundmanpt 13 Jul 2015, 11:28


If you find the right lab person that really knows their stuff they can make your exact lenses for a rimless frame. What they need to do is on the edges simply use a tool that cn dig out where the screws are to be placed. It takes time but it can be done. In other words just where the arm (temple ) needs to attach is where you route out the plastic that way the screw can be attached.

About 20 years ago I had a sizable collection of the old Art Craft 3 piece style frames that was held together by the lenses. In other words you had the 2 temples and the bridge with the 2 lenses. Anyway they were all from the donation boxes I picked up from. I once asked what they did with those types of frames and was told that because they were made of gold they melted them down for the gold which at that time amounted to about one dollar. That was why I started to just hold on to them because I knew they were far more as antique glasses. But I didn't need so many so after holing them a few years I started showing them to some of the younger opticians. If I could tell that some one really had an interest in them I would give them a pair. I remember one young lady wanted a pair to put on a big stuffed bear she had. Several of them were wanting to put their own prescription in them so they could wear them. One wanted a pair to make a display with an old book opened up and the glasses laying on the pages. Anyway one young lady wanted them so she could put her prescription in them. Now unlike rimless where all you need to do is drill the holes these glasses were made in such a way that the lenses slide into an opening of the temples and the opening was very small. These old glasses were in the days when lenses were glasses and if you dropped your glasses they would shatter in many pieces. Her prescription wasn't quite -20.00 something but more around -10.00 but this was before hi index came out. This gir was not a lab person but she knew what needed to be done if she wanted to put her rx in them and it meant hand cutting a notch on both sides of each lens (total of 4) It took he r a while and she finally had her glasses she loved them because they were so light.

Patrick B 13 Jul 2015, 09:11

Hi Calcat:

Yes, those are some pretty thick lenses. I've seen thicker but only on the rarest of occasions and then, I think, when someone had a very strong prism prescription in addition to his myopic prescription.

I don't know what your prescription is but mine is -22/-23 and I have always tried to minimize my prescription by wearing small frames (46/47mm) and the highest index lenses available which are the 1.9s for a full aperture lens. (I also have blended myodiscs with 23mm bowls.) The 1.9s are approximately 8 - 9 mm thick and biconcave. Anyone who knows something about glasses can still see that they are really strong. First of all, my eyes are quite small behind the lenses and the frame, frankly, is a bit too small for my face. I usually wear contacts and one friend of mine who is -12/-13 actually asked me if I needed to wear correction full time. Funny that someone with severe myopia wouldn't be able to spot my own myopia which is twice his.

Let us know what your prescription is and thanks for being upfront about your own myopia. People really shouldn't ask such insensitive questions but do. Oh, well. I get asked every so often when I need to push my glasses up against my eyes to see better in the distance. I do it without thinking and sometimes it has been noticed.


30calcat 13 Jul 2015, 05:17

My frames are semi-rimless too, but the lenses dominate over the frame:

I would try true rimless if I could, but I don't think they make drill posts long enough for the drilled rimless style

thebrit 13 Jul 2015, 01:31


I found your mail concerning remarks made about your glasses very realistic. I too have the outer edges of my lenses at 14mm & get similar questions.

My glasses are semi rimless or full frames, but I have always wanted some rimless glasses.

Your post & attitude in wearing rimless glasses with 14mm lenses has inspired me to join the club...thanks!!

 10 Jul 2015, 15:09

"Another comeback that I have used is. Yeah,they are pretty strong,but at least I don't need them for driving.

Or I have said,I had to get these after the rigorous study required to be an airline pilot"


Likelenses 10 Jul 2015, 13:55

Another comeback that I have used is. Yeah,they are pretty strong,but at least I don't need them for driving.

Or I have said,I had to get these after the rigorous study required to be an airline pilot

Nick 10 Jul 2015, 13:41

@ Jarred

Yeah used to the usual stares long ago,couldn't really care,often find some people coming back in close proximity to get another look,maybe it's something they find fascinating

Likelenses 10 Jul 2015, 13:38


You could come back with,these are not glasses ,they are ice cubes in a frame.

I have used that comment, regarding my -10.5s and is is a real ice breaker. No pun intended.

Jarred 10 Jul 2015, 13:02

Although not quite on the scale of a -20 prescription, I did have 20D of prism 'pre op' which resulted in lenses about half an inch thick at the outside edges. No one ever commented directly, although I did notice some odd looks when in a crammed lift or other such close quarters.

If someone did comment, I'd like to think I'd be quick enough off the mark to say "Who said that?"

Nick 10 Jul 2015, 10:46

Having severe myopia too at -20,I only wear glasses,as battle with glasses are blended myodiscs tinted @ 75% grey with antireflective coatings.i often get asked questions along the same lines,I just confidently reply "think how strong my eyes must be to be able see through these things"rarely get another remark about them.

30calcat 10 Jul 2015, 07:43

Question for other wearers of thick glasses: How do you respond to people who blurt out to you "Those are the thickest glasses I have ever seen!"

I enjoy wearing my 14mm thick lenses, completely exposed in a rimless frame. I get this comment every now and then from all sorts of people I know to people I meet for the first time. Every time I end up at a loss for words to respond. In my mind I take it as a compliment and want to just say "Thanks!" but I wonder if it might seem unexpected and strange to everyone else. What I don't want to respond with is something that solicits pity, as I can function normally, see 20/20 with my glasses, and do not want people to consider it a handicap. So I refuse to go with common responses like "I'm totally blind without them."

In the end the silence is awkward and the person changes the subject, embarrassed at what they said. Perhaps what I should say is "Thanks, I like these glasses" and open the door for a conversation about glasses if they happen to be an OO.

Fake Myope 09 Jul 2015, 23:19


I'll never discuss GOC with them. They know I'm obsessed with glasses because I'm bad at hiding my obsessions. I'm not sure if my vision field is affected that much. I don't notice much of a difference when I wear contacts. I wear pretty big glasses, I hate small glasses. I also notice that things look smaller in my left eye when I'm bareyed.

Likelenses 09 Jul 2015, 22:43

Fake Myope

I think that you would benefit from GOC,in that your + 4.25 eye would have much better visual field. You are probably not aware of how restricted that eyes field of vision is,but by use of a minus glasses lense over a plus contact you could have a normal ,or better than normal field.

This is perhaps an avenue to run by your parents.

Fake Myope 09 Jul 2015, 11:39


I actually have worn contact lenses, but I've only worn dailies. I used to wear aquacomfort plus, but I changed because of astigmatism. I live with my parents, so I won't do GOC until I live alone and in another city. My prescription fluctuates a lot. My current prescription is R: sph +1.00 cyl -0.75 axis 174 L sph +4.25 cyl -1.50 axis 10. I looked at the prescription range for aquacomfort plus and it only went up to +6.00. That means I'll only get to wear about -1.50. If I'm going through the trouble of GOC I don't want to wear a feeble prescription like that. I'll probably get fitted for monthlies one day and use the same brand.

Soundmanpt 09 Jul 2015, 09:13

Fake Myope

If you prefer your look wearing minus glasses then you should give a try at GOC If you provide your full prescription and the prescription you would feel comfortable wearing in public. There are more than enough people in here that can then provide you with a good combination for the GOC.

Since you have probably never worn contacts the first step would be to call for a contact lens eye exam as if your wanting to order colored contacts. This will get you the base curve and diameter you need so you can order the contacts you will need for GOC. Getting the glasses you want is even easier.

You only need to ask for help and it is here.

Fake Myope 09 Jul 2015, 08:50

Thanks. I don't want to induce myopia. I get enough eyestrain already. My worst eye is just over +4.00, so I probably won't be able to induce myopia. The most I might do is taking pictures of myself wearing thick minus glasses or GOC.

Likelenses 09 Jul 2015, 01:35

Fake Myope

You look really cute in those minus lenses.

You are quite young,so most likely you could induce some permanent myopia,by wearing minus lenses full time.

Ask,and we can tell you how to do it.

Fake Myope 07 Jul 2015, 23:58

I'm female. This is what I look like as a myope. I was trying on glasses at a second hand store for fun. Didn't end up buying them. My actual glasses are more in style. I like the smart and humble look the minus glasses give me. I look too sexualized when I'm not wearing minus glasses.

Likelenses 07 Jul 2015, 23:21

Fake Myope

Are you a male,or female,and could you provide us with a link to your photos as a myope?

Fake Myope 07 Jul 2015, 22:50

I'm not sure where to post this, but here it goes. I'm farsighted, but I like the clean and smart look of minus lenses. I don't do GOC so I just wear my real prescription in real life. On the internet I show people pictures of myself wearing strong minus glasses. I quite like being a fake myope on the internet. I feel less sexualized and people seem to criticize me less. Anyone else have this experience?

Roy 07 Jul 2015, 07:57


Thanks for your reply. I agree it's a difficult problem to resolve. I recently bought a pair of glasses with this new prescription from a high street optician. I had new lenses fitted to an existing frame (replacing 19 dioptres shared base-out prism lenses with the new prescription of 22 dioptres). The dispensing optician measured the PD, and marked the optical centres, with the old lenses in, and got a PD reading of 62mm. If I had bought new frames and she had marked the plain display lenses she would have got a reading nearer 68mm. The new glasses are OK, so I assume the 62PD is the correct one to have used. (But perhaps it should have been reduced slightly to allow for the increased prism from 19 to 22 dioptres).

I think the problem is that prescribing prisms is quite rare these days, so the skills are not widely known. My optician said she rarely comes across prisms and mine was the highest prism prescription she had ever seen. (I also have 2 base-up and 3 base-down.)

I am very pleased with the end result though, especially as the prisms are combined with myopia, astigmatism and progressive lenses. The resulting edge thickness of nearly 1/2" is a price well worth paying for good vision.

More thoughts from any contributors would be appreciated.

Cactus Jack 06 Jul 2015, 13:55


I have to admit that I have wondered a bit myself about how to ask the lens maker to apply the correction or not apply it. The amount of correction is derived from Prentice's Rule but you don't want to do the direction twice as in "too many cooks".

Perhaps Soundmanpt, who has experience as a Dispensing Optician, can assist. I suspect a note on the order, to please adjust the PD for the prism correction would alert the lens maker that the PD is with both eyes looking straight ahead would be a signal that PD correction is needed, but I need to defer to someone with more practical knowledge and experience.

As you may know, I often need more BO prism than you do and it is high enough that no online retailer will touch it. I have also found few Dispensing Opticians who know how to order glasses with a significant prism correction, The result has been glasses where the sweet spot with the best VA is nowhere near where my eyes are pointing. Ideally, the Optical Center of the lens is coincident with the Central Axis of Vision of each eye. Prism itself does not have an optical center, but Sphere and even Cylinder correction do and it needs to be right. If it is not, my experience has been that it introduces unnecessary sphere and cylinder distortion, which reduces VA.


Roy 05 Jul 2015, 13:32


I wonder if you can help me with a prism query. I need to order a spare pair of glasses online. I have 11 dioptre base out prism in each eye. I am not sure how to enter the PD. If I remove my glasses and shut one eye at a time I get a PD of 68mm. Wearing my glasses with the 22 shared base-out prism the PD is 61mm. Is this the PD I should enter on the online form and, if so, should I add a note to confirm that I have compensated the PD to allow for the prisms?

Trent 02 Jul 2015, 09:09

David A quick search came up with five results, you will have to check if they can re-lens your glasses:

The only one I have experience with is Clearly Contacts. Depending on your Rx they can be expensive. Sometime it is cheaper just to buy new frames and lenses.

David 02 Jul 2015, 07:24

Hi there,

Is there an online glasses re-lensing shop you would recommend where I could mail in my existing frames in Canada?

Cactus Jack 23 Jun 2015, 14:15


Incorrect PD causes Induced Prism and possibly some Induced Cylinder. The amount depends on the basic prescription in the glasses. PD too wide Induces Base In prism, which causes the eyes to try to turn outward or diverge. PD too narrow Induces Base Out prism, which causes the eyes to try to turn inward or converge. You might check out Prentice's Rule to get an idea of the amount.

I believe there was a discussion about Prentice's Rule on Opticampus a while back.

Wearing unneeded prism is not considered to be a good thing, but small amounts are probably harmless.


EyeTri 23 Jun 2015, 13:39

Two days ago I posted a question about the effect of wearing glasses with an incorrect PD, and to date have received no answers. Does anyone have any thoughts on this problem?

I know that I can send the glasses back and have the lenses remade, but this is two or three week turnaround and aside from the PD problem the lenses are fine.

Aubrac 22 Jun 2015, 04:23


There are many UK online glasses retailers doing good quality but cheap eyeware.

Select Specs in Westgate, Kent, does glasses complete from £6, although you can add thin lesnes, transitions, tints, etc, which will put the price up.

You could order a spare pair with transition lenses which can double up as sunnies.

I bought a spare pair of glasses from China at an amazing £2 including postage - they had moulded hinges and certainly wouldn't take rough handling but the lens quality was ok and available up to -6.00.

EyeTri 21 Jun 2015, 09:39

A few days ago I received a pair of glasses that I had sent out to an on-line company that does lens replacements. The new lenses are 8x35 flat top trifocals.

I was looking at these glasses this morning and noticed that the trifocal segments appeared to be too far apart. I measured them, and the near PD in the new lenses is 4mm wider than I had specified (66mm instead of 62mm). I have no way of measuring The diatance PD, but I assume that it is 4mm wider also.

Is there any problem with wearing glasses with a wider than specified PD?

Soundmanpt 17 Jun 2015, 15:27


Just as you said glasses and contacts and such can be very expensive if you buy them at the optical shops. But like "SC" suggested it is a much better idea to buy your glasses on line. You can also buy contacts on line but to be honest the savings isn't all that much from your local optician. The glasses is where they really rake in the money. There are quite a few good quality on line retailers. I have dealt with a few of them and they are all good. The main reason I prefer Zenni is because they never use overstock frames. Nothing wrong with overstock frames except i need to keep samples to show people and if I am showing samples that quickly are no longer available then that doesn't work for me. But other wise for you they are fine. So I know Zenni quite well and know that the quality of glasses is every bit as good as any glasses you can buy at an optical shop. Alos something that not all of the on line retailers do is that soem of them charge you $5.00 or more for shipping fo each pair of glasses you order even though you maybe ordering 3 or 4 pairs at one time. Zenni only charges one shipping fee and that is for one pair or 100 pairs. Only $5.00. So if lets just say you decide to order 2 pairs of glasses one being regular glasses and one being rx sunglasses with shipping and all you should still be under $50.00.

The suggestion that you should have a spare pair of glasses is something you should consider. You could probably get by with your old pair if your inside but for driving not the best idea because they would be a little too weak for your eyes.

I think there are many in here that will agree with me that once you start buying your glasses on line you wont ever buy glasses from a local optical shop again. I can tell you I have tons of friends and family now that never even consider getting their glasses from a local store anymore.

SC 17 Jun 2015, 10:26


Yes it is expensive - you can get things cheaper online: Zenni is very cheap but there are also UK companies such as Glasses Direct.

Some countries such as France, insist that you have a spare pair of glasses in the car for driving an may fine you if you don't

SC 17 Jun 2015, 10:26


Yes it is expensive - you can get things cheaper online: Zenni is very cheap but there are also UK companies such as Glasses Direct.

Some countries such as France, insist that you have a spare pair of glasses in the car for driving an may fine you if you don't

Nichola 17 Jun 2015, 07:52

I've got normal glasses and contacts shortsighted -5.00 should I get prescription sunglasses? I've just paid £150 for new glasses lenses £25 eye test and pay monthly £32 for contacts. The prescription sunglasses I want are £200. Is it best the get them or wear normal sunglasses with contacts? I was thinking of cancelling my contacts and wearing glasses more. It's expensive being shortsighted how do all other people afford it? Some people just have the same glasses all the time but I don't want this. They also said because of my prescription I should have another pair of glasses is case they broke and that was another £120

Soundmanpt 15 Jun 2015, 17:10


Unless your gf's prescription makes a really big jump, which isn't very likely to happen, then i completely agree with Crystal Veil that any high index lenses would be a waste of money. Her Prescription isn't that strong. If your really curious before she goes for her eye exam go to a store that sells over the counter readers and they are clearly marked and find a pair of say +2.00 or +2.25 glasses and even with a small increase that is about as thick as her lenses are going to be.

Nichola 15 Jun 2015, 15:44

Here in the uk you don't even need a eye exam all you have to do I read a car number plate. Amazing people fail that and need to go to the opticians for glasses then you have other people that get glasses after they have been driving for a few years! So if you didn't need to go to the opticians you could never have your eyes tested. I dont mind spending money on glasses because they are worth it when you wear them all the time. -5.00 now so bad but half of people are shortsighted so I'm in the unlucky half.

Soundmanpt 14 Jun 2015, 13:24


The optician was correct in telling you that with your change in vision driving with your current glasses would be unsafe not only for you but others on the road as well. If your increase had only been -.25 or maybe even -.50 your vision with your glasses would have still kept you better than 20/40, but with an increase of -.75 your vision with your glasses would not be that good.

Yes I am sure that there are far too many that need their glasses changed or don't even have glasses. It might be slightly better here in the US because most of the states require you to renew your driver's license at various times. In my state it is every 6 years. The renewal includes an eye exam and your vision with or without correction must be at least 20/40 to pass. Interesting that they did that test in the UK by stopping drivers and having them take a vision test. If I am correct you only get an eye exam when you first get your drivers license and never again.

Crystal Veil is correct that you should do better with reglazing by going on line. The other option I think which maybe even better is to just go on line to Zenni ( and buy completely new glasses with your updated prescription. I looked recently and they offer over 800 pairs of glasses for less than $22.00 and that even includes the AR coating (anti-reflective) From the time you place your order it will be less than 2 weeks for you to find your new glasses in your mailbox.

Crystal Veil 14 Jun 2015, 13:19


going for 1.74 lenses is pointless unless your gf has extreme astigmatism, say +6.00 or upwards. My advice would be to choose the frame with great care.

til 14 Jun 2015, 12:13

Question about plus glasses

I know how different lens indexes affect the appearance of minus lenses but I have no clue about plus lenses. My girlfriend (26) is hyperopic with +1.75/+1.00 and astigmatism (don't know the exact value) and will have an eye exam this week. I suspect she will either get a low increase or the prescription will more or less stay the same. She is gonna go for new glasses anyway. As I love the look of minus glasses and don't fancy the look of plus that much I was thinking about getting high index lenses (1.74 or higher) for her.

Do you guys think that would be worth the money in matters of distortion of the glasses and lens shape?

Julian 13 Jun 2015, 02:51

Galileo: longer ago than that, 1970s maybe, a chief constable, it might have been in Hampshire, ordered eye tests for all his officers, and the majority of them were taken off driving duties till they got glasses!

Crystal Veil 13 Jun 2015, 01:24


if you'd prefer to keep money in your pocket, check ciliaryblue. They reglaze your glasses for about one third of what you pay your optician and the lenses are perfect. I just received a box with three pairs, two Zennis for my partner Nel and a pair of Silhouette glasses (made in 1984) for one of my recent models. Nel is excited about her new glasses. They look as if they are -6 / -7 instead of -12. The Silhouette glasses look as if they are brand new.

Galileo 13 Jun 2015, 00:06

Hi Nicola, I remember a survey done in the UK in the 1990s in which people were stopped whilst driving and had their eyes tested. The result was that more than 50% of the people who were checked were driving with vision which was not up to the required standard. Either they had no correction and they needed correction or they had correction but it was not strong enough. You are right - it happens a lot!

Nichola 12 Jun 2015, 18:49

This must happen to everyone? After I had my eyes tested and found out they got worse I had to get new glasses. My optician says I can't drive wearing my old glasses so i got new contacts and am just getting new lenses in my glasses. Lenses only were £150 for glasses and will need changing again next year is so anoying. I got the contacts straight away went up from -4.25 to -5.00. There must be lots of people wearing not up to date prescription? Is it really that bad?

Soundmanpt 08 Jun 2015, 09:55


So actually your lenses are polycarbonate which is good quality lenses. Polycarbonate lenses is a stronger type lens and is required for children's glasses because they are pretty much unbreakable. But if you happen to play any sports having polycarbonate lenses is really much safer for your eyes. It really makes good sense because you or your friend really need your lenses made thinner. I didn't want to say anything but if they had indeed sold you high index lenses then they would have sold you something you didn't need, but using polycarbonate lenses is a very good option.

I'm sure your friend would have been more than happy to keep your glasses on the rest of the evening because your glasses provided her with very crisp vision. When she put her own glasses back on i'm certain she felt like her glasses were too weak for her eyes because that sharp, crisp vision wasn't found in her glasses. And you on the other hand even though you could see reasonably well with her glasses things in the distance were at least fuzzy if not slightly blurred with her glasses. So i'm sure you were glad to put your own glasses back on. Now if her glasses were -3.50 as you probably already know you would be the one wanting to keep her glasses because it would be you with the sharp crisp vision and she would be the one missing not having her glasses on. But it's fun tor try other peoples glasses.

After having your glasses on and seeing so well with them did she think that she may need to get stronger glasses? That would be the normal reaction. Next time you see her you need to let her know that her eyes are just fine and her glasses that anyone trying on glasses just slightly stronger than their own glasses is going to see better. Even someone with perfect vision is going to see better with -.50 glasses.

SoCal 08 Jun 2015, 09:18

Thanks for the feedback. I just looked online at the site that did my re-lensing and they use 1.59 high index lenses standard. I guess my friend just had standard CR-39 lenses from her optician. I guess that is what made the difference in strength appearance. Also, my friend did say that she saw better with my glasses on and as predicted my vision wasn't as crisp as it usually is.

Soundmanpt 07 Jun 2015, 06:30

So Cal

If your friends frames were larger than yours that will have an effect on how thick her lenses appear and of course if your lenses are high index which I assume they might be and hers are the standard CR-39's that would make her lenses look stronger than yours. But really if I was placing an order for either one of you ladies I wouldn't even recommend high index lenses since your prescriptions really aren't strong enough to warrant the added cost of high index. I have placed many orders for glasses with about the same prescription as you and your friend and their glasses always look very nice and the lenses look nice and thin. I use Zenni and for anything under -5.00 I only order the lenses as the 1.57 which are the free lenses. They do offer 1.50 lenses but these lenses are mostly for someone with a very weak prescription and they frame they are getting needs a thicker lens.

So with your glasses only being -.50 stronger than hers I would assume you both could see pretty well with each others glasses when you traded. Your friend probably even better than you because her eyes were enjoying being slightly over corrected with your glasses. Sadly for you her glasses didn't give you the same effect by being under corrected, but fun none the less.

Galileo 07 Jun 2015, 05:42

Hi SoCal, yes it could just be lens material. I have a friend who has both high index and CR39 glasses, the difference is remarkable. The high index lenses are around 20% of the thickness of the CR39 lenses even though the high index frames are bigger. The power rings look compressed in the high index and the overall effect is that she looks to have a lower Rx when wearing the high index.

SoCal 07 Jun 2015, 03:11

I was at dinner last night and I noted that my friends glasses lenses seemed thick with a decent amount of power rings, etc. I too was wearing my glasses and felt that mine didn't look as strong as hers. We got on the topic of laser eye surgery,contacts and glasses and eventually traded glasses and rx information. We found out we were close in rx strength, she at a -2.50 and me at a -3.0 in both eyes. So, my question is, why did hers seem so much strong and thicker if her glasses were actually -.50 less powerful? Could this solely be lens material?

High Myopic 12 Apr 2015, 14:35

How much cheaper are CR39 lenses than high index? I want to get a new rimless pair of double bridge aviator glasses. I want the biggest aviator pair I can get. I want to get a pair that does not fog up as much as my current pair does. I think going rimless would help that problem. I love thick glasses lenses.

sam12744 30 Mar 2015, 04:38


You could try : as a source.

Roy 30 Mar 2015, 00:41

The Brit,

Sorry but I think I was wrong about the lenticularised prism. What is your prescription? I posted my latest in the "Post my Prescription" thread.


Soundmanpt 27 Mar 2015, 07:41


There are several things you can do. First of all ask that your lenses be made with CR-39 lens material which is the thicker plastic. Bigger frames will also help make your lenses a little thicker on the outer edges. You also may want to just go on line and order glasses with a little stronger prescription than you currently wear. Nothing to drastic but even increasing each eye by -.75 should make your lenses a bit thicker and your eyes shouldn't have any problem adjusting to the stronger lenses. There are several on line sources that you can order your glasses from that don't require a verification from your doctor. Eye Buy Direct ( and Zenni ( are ones I would suggest because their prices are very inexpensive and the quality of the glasses are good as well.

jack 27 Mar 2015, 07:02

the brit,hi I have 14 BO each lens so I know about the thickness of the lenses that prisms can cause,i live in yorkshire

TheBrit 27 Mar 2015, 06:29


Thanks for your posting on the subject of prisms. Like you my prisms are ground into the lenses but with BO they have rather thick outer edges.

Lenticulerized Prisms are ground into the lenses and cut away on the outer back edge to reduce thickness & weight, a bit like myodisc lenses I suppose. If you look on the website of Chadwick Optical in the USA you will see a profile of this type of lense..unfortunately they are wholesalers & cannot supply the public. However when I find a supplier of this type of lense in Europe, I will post more info, as for high prism prescriptions it would be a good alternative choice to standard lenses.

Roy 27 Mar 2015, 03:02

The Brit

I think what you refer to as lenticularized prisms are also called Fresnel prisms. They are made of thin (about 1mm) flexible plastic and can be fixed to the back of a spectacle lens then trimmed to match the lens profile. They are effectively a lot of small prisms and viewed from the edge they look like a row of saw teeth. They can be fitted at any angle to give base up, down, in or out, or a combination of these.

I think they are mainly used on a temporary basis to evaluate a person's prism requirement before replacing with a proper ground prism lens if needed. I have had ground-in prisms in my glasses (now quite strong) for around 50 years. I have also had fresnel prisms temporarily on a couple of occasions to evaluate a new prism requirement. They work effectively as prisms to eliminate double-vision but do reduce visual acuity a bit so they are normally only fitted to the lens of the non-dominant eye. They also have a use in very high prism prescriptions where it is not possible to grind lenses with enough prism.

Trent 26 Mar 2015, 18:20

Check out Optical4Less they can make even a mild Rx look super thick.

whynot 26 Mar 2015, 16:33

Odd question - I have a low script (-.5, -1) and want to make my lenses look thicker. Any suggestions e.g. materials adding a small plus etc.?

I'm in my late 20s if that makes a difference.

TheBrit 26 Mar 2015, 09:49

I have posted to this site in the past. I see again that the subject of prisms is frequently on topic!!

Does anyone here have any experience of' Lenticularized prisms'? What are they like, & what are they like to wear.

Likelenses 23 Mar 2015, 21:57


As far as thick edges,cut in,and minification of your lenses,Wear them with pride.

A lot of us guys love to see women with these type of lenses.

Stingray 13 Mar 2015, 13:05

Calling on all optical experts regarding the glasses I wrote about. I have a +1.50 correction in both eyes. I have 2 pair of computer glasses with single vision lenses. One has a power of +3.25 the other +3.50. When I look through both glasses with the myopic glasses over them, I can see clearly. Based on that, what would the approximate sphere power of the lens be? I also noticed that the double vision is up and down rather than left and right. The top part of the lens is not that thick nor is the bottom of the lens.

bracesfan 13 Mar 2015, 00:20

The method to distinguish is simple. Just look at two parallel lines (e.g. opposite sides of monitor) both through glasses and beside them simultaneously. If both lines are moved in the same direction through glasses then prism is present.

Pushing effect in your thrift glasses needn´t be caused by built-in prism. It can be just from different pupillar distance of eyes and distance of optical centres of lenses. Then the glass gains prismatic effect (Prentice´s rule).

Stingray 12 Mar 2015, 12:37

I had my slightly myopic wife try them on (she is -3.00) and she said they make her see double and it feels like her eyes are being pulled sideways. So based on that I think there is significant prism in these glasses. The outer edges are also quick thick, at least 6mm worth.

astigmaphile 11 Mar 2015, 14:29

I have a few pairs of glasses with prism in my thrift store collection. Where the edges are thick is one way to tell if there is prism in them. BO and BI make me see double for about a second when I put them on or take them off. BU/BD make me see double, period.

astigmaphile 11 Mar 2015, 14:29

I have a few pairs of glasses with prism in my thrift store collection. Where the edges are thick is one way to tell if there is prism in them. BO and BI make me see double for about a second when I put them on or take them off. BU/BD make me see double, period.

Crystal Veil 11 Mar 2015, 13:51


one way of checking is to see if the lenses are thicker on one side than normal. It helps if you have a trial lens set to compensate for the Sph Rx. I discovered about a dozen glasses with prism that way when going through my collection.

Stingray 11 Mar 2015, 09:51

I just bought a pair of glasses in a thrift store today and think they may have prism lenses in them. I am not familiar with prisms, so is there any way I can determine if the lenses are prism or not? I know with astigmatism if you rotate the lenses and see distortion, then there is an astigmatism correction, but prisms...?

John S 08 Mar 2015, 15:25

I seem to recall someone posting they had found a lab that would sell lenses to them. I am interested in getting some uncut lenses.

If so, let me know at jsscene at sxsco dot com.


Soundmanpt 08 Mar 2015, 09:45


I agree you wouldn't think a few mm difference would make much of a difference but it does. Yes the small frames that had been so popular for so long really didn't provide much of a field of vision. I have to think the reason the bigger "hipster" style glasses have become so popular and even has made many return to wearing glasses is in large part the larger viewing area those glasses provide.

There's no doubt that your new glasses are going to give you better, clearer, vision than your contacts will. Like your doctor called it, compromising, is exactly what your doing by increasing your distance (SPH) and leaving off your astigmatisms (-.75 / -.25) But they do this because toric lenses which correct astigmatisms are about 3 -4 times more expensive than regular lenses are.

The glasses your considering is the sister of the ones that I have found extremely popular with so many. In fact I am planning on ordering a sample of both colors they come in for my sample case. The ones I have been ordering so far are #220421 and #220431 and they are the exact same size as the ones your considering.

Maggie 07 Mar 2015, 22:25

Soundmanapt, thanks. I'm surprised that just a few mm can make a difference. I really like the big field of vision I have with those glasses. Part of the reason I've almost always worn contacts is because old school small glasses are hard for me with a small area of vision that isn't blurry as hell. Now to just get myself to wear these out of the house since I can actually see very well with them. I know I will see better driving at night because they have an astigmatism prescription and my contacts don't (my doctor says that prescription is a compromise).

I'm thinking of trying a pair of the "Melissa" 283621 in high index since Zenni is so cheap. I got those for new sunglasses and they seem to have less cut in but I figured it's just hard to see that with the dark tint. I figured not to bother with high index since I like the thick plastic frames and those do hide all the thickness well.

guest 07 Mar 2015, 16:34

hmmm... all my life I thought "power rings" were something worn by the supervillain Mandarin in IRON MAN.

ann 07 Mar 2015, 12:05

soundmanpt,yes its for my left eye,i want base out

Soundmanpt 07 Mar 2015, 11:46


Okay first of all you need better information. You have indicated a prescription for your right eye twice and nothing for your left eye. I would assume that the +3.00 is actually your left eye?

As for as the prism your asking for. The highest that Zenni goes to is 5.00 and you need to determine if you want it as base in, out, up, or down? You do understand that if you don't really need prisms your going to ruin your eyesight?

There is no reason for me to enter the information for you since it really isn't that difficult to do and I will happy to guide you if you have questions.

ann 07 Mar 2015, 10:06

hi soundmanpt could you possibly arrange to buy me some glasses with prisms the higher the better,my rx is right +2.75/cyl -.50/axis 60,right +3.00/cyl -.50/axis 90,if you can we can arrange payment,thanks

Soundmanpt 07 Mar 2015, 08:49


I was just looking at the glasses you got and they are really pretty cool but they are quite big. Even the knock off Ray-Bans that they offer are only 137mm and these glasses are 141mm. Most of the young ladies I sell glasses to wear 128mm - 131mm except for the "hipster" glasses which are meant to be slightly bigger and now I have even found a miniture version of the hipster glasses and recently placed an order for 3 pairs of them. They are also from Zenni and the #293125. I'm sure the size has much to do with why your noticing the cut-in more. But I doubt anyone except you will ever pay any attention to the cut-in but instead will complement you on the glasses because they do look very nice.

Cactus Jack 06 Mar 2015, 23:13


Power Rings are actually internal reflections of the edges of minus lenses. You can prove this by touching a wet finger to the edge of the lens and noting the change in appearance of the power ring in that area. The wet finger helps fill in any roughness of the edge. A higher index lens will have thinner edges and less obvious power rings. Two things that might also help is a frame that blocks light from entering the lens from the side and or a VERY light tint that is almost invisible. The light rays entering from the side have a much longer distance to travel that light rays passing through the lens normally. The longer distance allows even a little bit of tint to reduce the brightness of the power rings.


Maggie 06 Mar 2015, 20:41

Thanks for the replies. Will high index at least make the power rings show less?

I chose frame #628221 which are almost identical to my last pair although I think they may be a bit tiny wider. It's hard to say since my last pair were stolen a few months ago and my glasses before that are really small. I hate small frames, I think the big hip ones are more stylish and flattering, but because I'm blind as a bat and wear contacts 90% of the time, I prefer to have a bigger area of usable vision and less of a fishbowl effect from bigger frames.

I actually think glasses can be really sexy on some people, but I feel really self conscious when I wear them, especially in front of people that don't usually see me in the coke bottles... It seems some gentlemen here like that look but I don't think most of the world does! I'm trying to get myself to wear them more since my eyes have been getting more irritated from too much contact wear lately and it's just disappointing how much different they look with my lenses than trying frames with plain lenses on at the shop or a virtual try-on.

motard 05 Mar 2015, 11:30


I went from -7.00R -6.00L to -8.00R -6.75L in same frame with 1.57 lenses and no one has noticed increase in thickness , cut in, or power rings. Although I do :-)

Soundmanpt 05 Mar 2015, 09:58


Going to high index will only make your lenses thinner. The power of your lenses will still be the same with regular lenses as with high index so cut-in would be the same as well. Just as Crystal Veil if you want the cut-in to not show up as much smaller frames work well for that. Your nearsighted so that means your lenses get thicker as you go out to the edges. I'm sure you have noticed when you have cleaned your glasses that the center part of your lenses is thinner than the outer edges. So if your lenses are smaller the cut-in is still there just less noticeable. But to be honest if you prefer the bigger style "hipster" frames I wouldn't let the cut-in be an issue. Remember most people are really only going to notice that you got new glasses and never pay any attention to your lenses. Crystal Veil has provided many pictures he has taken of many young ladies wearing stronger glasses than yours and these women are stunningly beautiful, so you should be as well.

Crystal Veil 05 Mar 2015, 01:27


you had an increase of -0.75 so yes, that does make a difference. The size of the eyes behind glasses looks about 1.5% smaller after your increase. This has nothing to do with high index lenses. It's also normal that you see a bit more "cut in" effect with your higher prescription. If that difference is more than you expected, it may well have to do with the choice of your new frame. Big, angular frames tend to produce more "cut in" and stronger power rings than smaller, oval frames. You are probably better off if you spend your money on a different Zenni pair with 1.57 lenses.

Maggie 04 Mar 2015, 23:20

How much of a difference do high index lenses make for getting rid of that cut in squished face look with bad prescriptions? I just got a Zenni order, this broke grad student took a chance on the free 1.57 lenses since I've those are pretty thin with Zenni. And they are really nice and thin, but I feel like my face has that shrunken in look and my eyes look smaller than with my old glasses from the opticians that were high index, to the point I feel self conscious. Should I go for higher index if I try buying again?

My new prescription is:

R -5.25 -0.75 10

L -5.50 -0.25 92

The old one was:

R -4.50-0.75 10

L -4.75

Doesn't seem like the new one should look as much stronger as it does!!!

til 19 Feb 2015, 04:32

Crystal Veil

Thank you for the reply, most likely no prism in them then.

SoCal 18 Feb 2015, 14:51


I actually got my own rx on the glasses that I sent in but sadly my rx has changed slightly and I am still not sure if I want them replaced again since it's only a -.50 change. The rx that I went off of the first time was the rx I got last year. I don't know what I am going to do. I have my new contacts so I will just wear those and think about updating my glasses. I can tell there is a difference but i don't know if it's enough to even bother.

Soundmanpt 18 Feb 2015, 13:44


Last year I took a designer frame (BeeBee) to my friend that manages a Sam's Club Vision center. She was nice enough to replace the lenses for me for a customer including the AR coating for $70.00. The prescription lenses were $40.00 plus $10.00 for using a furnished frame and the rest was actually another $40.00 for the AR coating but she only charged me half. So the real price was $90.00 and i had a legit prescription for the new lenses.

By the way this is the same manager that I was always telling about Zenni until she finally went their herself and ordered 3 pairs of glasses for herself. What was even more impressive was that she upped her own prescription by -.25 even after just getting her eyes examined and being told her eyes hadn't changed. But even with the added increase her glasses were still only -1.00, but she said she could tell the difference when she was driving at night from her old glasses.

The biggest thing about $39.00glasses is that they will make the prescription to whatever you want without any question. So when you sent your frame there and had lenses made did you get your actual prescription or did you up it slightly?

SoCal 18 Feb 2015, 13:20


Yes, 39dollarglasees will put new lenses in your existing frames. The price is actually a little steeper than I remember with AR coating but it's still less than what I paid for my OP frames by far. This was from my order I placed at the beginning of the year. The company is based in NY and the turnaround was about 14 days, including shipping to them and having them be returned.


Lens Package Selected: PKG (AX) - Clear Polycarbonate (1.59 index) Lenses w/ Premium Anti-Glare Coating

Price: $63.95

Soundmanpt 18 Feb 2015, 13:09


Thanks for that but if i ever were to do that for someone I want to be as sure as possible that the glasses will at very least be returned in good order. I don't ever want to have to tell some that their $400.00 frame was somehow lost. Actually so far no one has pushed me too hard about using their existing frame. I try hard to convince them that is a much better and cheaper way by just ordering a new pair online from Zenni.

til 18 Feb 2015, 13:03


I'm not sure about the United States but on eBay Europe companies offer lenses (limited range) and fitting for about 25€. Of course it's eBay and you don't really know what you get in the end but they seem to have good ratings at least.

Soundmanpt 18 Feb 2015, 12:38


That's nice to know. So you're saying that $ will make lenses for anyone's glasses for $45.00 and make the lenses to whatever you might request as a prescription (within reason of course)?

How much extra for AR coating as well? I do have people every so often ask about changing their lenses and want to reuse their frame.

SoCal 18 Feb 2015, 11:14


Another good place for glasses is I sent in my favorite pair of Oliver Peoples and had them relensed for around $45 including tax. They are another site that does not verify rx. I like using them because it saves me some $$ in the event that my rx expires or something happens to my glasses.

Soundmanpt 18 Feb 2015, 07:19


Thanks for correcting me. That surprises me that you can get an eye exam at Costco, but not be able to but glasses with that prescription. I assume that is because the doctor's are independent of the actual store.

I just knew that several years ago when i made up a flyer about ordering glass on line and indicated several places to get eye exams at a low cost the manager at my local Costco complained to be because I didn't include her store for getting an eye exam. I only assumed that meat you could also but glasses and contacts their as well. She was also the one that pointed out about the getting your meds from their pharmacy.

Crystal Veil 18 Feb 2015, 06:51


this is what I can tell you. There is no need to put those glasses on. You can easily recognize a prism in a lens. One side of the lens is thicker than the other side. This van be in a horizontal or vertical direction en perhaps also anywhere in between.

Putting prisms in varifocals - yes, technically it can be done but some 15 years ago, several chains refused to do this. My then partner clearly needed a prism in her varifocal glasses. I tested her vision with my trial lens set and even though it was only a mild prism, it made all the difference in the world to her. However, when we went to opticians with the trial lenses, they said that their chain would never agree to have the lenses made because seen from a math point of view, the solution was not 100% at all distances. We said that she would be happy to take the gamble (no complaints in case it would not work out) but the answer remained no.

This is from personal experience. I am sure that other ES members can throw more light on the matter.

til 18 Feb 2015, 06:03

Can somebody tell how to detect a prism correction in glasses looking through them but not neccessarily wearing them?

I bought a nice pair of glasses on ebay, originally just for the frame, turned out they came in prescription lenses.

They are most likely progressives with a very low (maybe +0,5)correction in the upper and a slightly higher (maybe +1,5) correction in the lower part. The thing is that although i dont require correction they seem to work perfect for computer work (I'm saying this having worn them only 5 minutes).

My intention was to replace the lenses but now I'm thinking why not keep them. It's definitely fun wearing them but of course I don't want to mess with prism.

Can you put prisms in varifocals anyway?

Jan 18 Feb 2015, 02:50

Hi guys,

thank you for your feedback. I will try and see how lucky I am trying out different shops such as Specsavers (Australia). In the long run I won't get around looking for a new ECP (and then ask him), but I would have hoped one could perform the calculations independently.

Thank you very much for sharing your advice!


SoCal 18 Feb 2015, 00:22

You don't need a membership for the pharmacy, booze or the optometrist within costco but you do need a membership to make a purchase in the optical department.

Soundmanpt 17 Feb 2015, 22:47


Are you aware that you don't need to even be a member to make purchases and I would assume that would also include getting your glasses adjusted at both Costco and Sam's Club. For what it's worth you can also make purchases at the pharmacy as well and not be a member.

SoCal 17 Feb 2015, 21:23

If you're in the states, you can also go to costco and they will do it for free. They will also do adjustments on your glasses even if you didn't get them from there so long as you are a member.

Likelenses 17 Feb 2015, 19:53

The recent discussion about PD prompted me to do a little research on the phoropter.

What I found is that most phoropters must have your proper PD set,so that the examiner has each lense properly centered before your eye. Therefore there is no reason that he could not provide the number to you,but you would have to ask the examiner for it . Probably best to do so right at the beginning of the exam.

Perhaps most examiners do not put it on the prescription is that they feel that the provider of the glasses should be responsible for it,and they would not want to be held responsible for a poorly made pair of glasses .

Soundmanpt 16 Feb 2015, 08:00


What "Likelenses" is suggesting is a pretty good idea. Remember even if one place refuses to do it you can still go to other optical outlets and ask. However here in the US I know that now many of the big chains are refusing to even provide the PD even if you got your eyes examined at their store. These stores are mostly owned by the same parent company and include Lenscrafters, Pearle Vision, J.C. Penny Optical, Sears Optical and target Optical as well as even Sunglass Hut. The reason they are refusing is because they know you need the PD in order to go on line to order glasses. Im have been preaching for some time now that when your booking an your next eye appointment for an eye exam you should be sure to ask if they are willing to provide you with both a copy of your eyes exam (by law they must supply that) and provide you with your PD measurement. If they say they can't or won't do that then simply thank them and let them know your calling another place. Trust me it won't take long until you find more than one place that is willing to provide that to you. Also beware that I have heard now that several places are making you pay as much as $25.00 just for your PD. Once again I suggest you move on to somewhere else when they want to charge for that.

Likelenses 16 Feb 2015, 02:45


I do not know what country you are in,but perhaps you could just go in to an optical store,and ask them to do the measurement,and any calculations that may be required.

You could maybe say that you have an expensive frame at home,with an out of date prescription,that you would like to have your new prescription installed into,and a family member is planning to take it to an optical store back home but the store does not have your PD.

I will be willing to bet that they will do the measurement free of charge.If there is a large chain type optical store,they would be most likely to do it for free,because the clerks at those kind of stores are less likely to consider it as a lost sale. You could also tell them that once you get the glasses,that you may be back to their store for prescription sunglasses.

Jan 16 Feb 2015, 00:39


Thank you for your response. You are right, consulting the ECP would be the preferrable approach, but I moved overseas (had the glasses for some time) and couldn't track down my old ECP. I just want to obtain a spare pair without finding a new ECP in my place at this stage. I am ok with it not being fully accurate, since it be affordable and not for permanent use anyway.

I am thinking that the measurement without glasses and distance correction for prism diopter should give me a reasonable approximation. Is this reasoning correct, or should I consider anything else in this calculation (other than ideally consulting an ECP)?


Soundmanpt 14 Feb 2015, 09:46


The safest thing to do is get your PD from where you got your current glasses. Since you bought your glasses there they shouldn't object to providing you with that information and if they do object then by all means let them know they have seen the last of your business with them. Because of your prism is much more critical that the PD be correct. Be sure to take note of for any other glasses you may want to buy on line.

Jan 13 Feb 2015, 15:07

Hi guys,

I am about to buy new glasses online (or rather spare glasses). I wear prisms but I will need to measure my PD. I understand that I would need to consider a PD correction according to Prentice's rule. Would I still need to do that if I measured the PD with glasses that already have prism correction? In this case the PD should already be correct since it considers the eye misalignment, or am I mistaken.

Alternatively, should I use 'old' non-prism glasses for PD measurement and do the usual adjustment?


AndyDalton 29 Jan 2015, 12:53


I would strongly advise you think twice about this.

I wear 12.5 base out prism in each eye full time. not by choice I might add. The problems it brings is fraught with frustration.

Dependency on prism is hard work, particularly as you soon get tired of the heavy lenses on your ears and nose, not to mention the hell you go through in summer because your glasses wont stay up.

This is a dangerous game you are playing, please think about this very carefully.

Cactus Jack 29 Jan 2015, 06:21


Yes, you could wear them full time, but be sure you really need to or want to.. 12 Base Out in each eye wii cause your eyes to turn inward (converge) about the same amount as if you were reading something at a distance of about 6 inches or 15 cm.

It is very possible that you could become dependent on them so be sure you really want that to happen. It is hard to reverse.

How long it takes depends on several factors. Your age, prescription, and if your eyes have a tendency to turn inward when you are completely relaxed and not concentrating on looking at something. Probably less than a month if you wear them full time. The clue that you are becoming dependent is that you wake up in the morning with double vision and find it more comfortable to put on your glasses with prism to fuse the images.

If you would provide your age and present actual prescription, it would be helpful. Was the prism in the glasses prescribed by an Eye Care Professional?


barry 29 Jan 2015, 05:15

Hi,I have a pair of glasses with 12 base out prisms in each lens,could I wear these full time and will I become dependent on them and how long will it take

Cactus Jack 27 Jan 2015, 18:57


Astigmatism in the -2.50 range is not common, but it is not rare either. Usually, higher values of Cylinder correction accompany higher Sphere values.

Your GF has significant myopia or nearsightedness. Most of it is probably Axial or True Myopia which is caused by a mismatch between the length of the eyeball and the total optical power of the eye's lens system. In the case of a person who is Myopic, the eyeball is about 0.3 mm per diopter too long and the images focus in front of the retina. Minus external lenses move the focus point of distant objects back to the retina.

Generally, Myopia is caused by excessive eyeball growth in adolescence and the teen years. Eyeball growth typical stops in the early 20s unless there is a strong genetic tendency toward myopia. Pregnancy can often exacerbate a tendency toward increasing myopia.

Astigmatism is generally caused by uneven curvature of the front surface of the cornea. Ideally, the front surface of the cornea is like a slice from the side of a glass sphere. The actual cause of Astigmatism is unknown, but it appears to be caused by uneven stress on the cornea which causes the curvature of the cornea to be steeper in one direction than it is in the other. This stress makes the front surface of the cornea take on the shape of a slice from the side of an American Football.

Glasses with both Sphere and Cylinder correction in any reasonable amount can be easily ground into glasses lenses. Toric Contact lenses can incorporate cylinder correction, but are hard to fit properly. Contacts need to move around on the eyeball to keep the tear film fresh under the contact lens and often tend to rotate as you blink. With as much cylinder as you GF needs, any mis-alignment of the contact lens axis will result in very blurry vision. Sometimes compromise prescriptions where all of the Sphere correction and 1/2 of the Cylinder correction is applied to Sphere only contact lenses, but with as much cylinder as your GF needs that might not work very well..

I hope this helps without getting too technical. Here is a link to an interesting piece about the eye.


NickM 27 Jan 2015, 12:33

Cactus, I'm 22 years old. I never had an eye exam and I have a good level in maths and physics subjects.

As far as I read, my gf needs around -6 for myopia and -2,50 for astigmatism. Isn't it a lot for astigmatism? Every time I heard about someone with astigmatism I remember it was no more than -0,50.

Crystal Veil 26 Jan 2015, 23:04

I use the same method as astigmaphile. My trial lenses were a buy at the Amsterdam flea market during the 1980's. This enabled me to make a catalog with the Rx of all glasses in my collection. Models posing for me are often surprised that I can predict how well they will see through the next pair of glasses. The method is works for the spherical strength and also for the strength of the cylinders. The only problem is the exact axis of the cylinders. In the catalog I only indicate if the axis is more or less vertical (close to 0 or 180), more or less horizontal (close to 90) or somewhere in between (45 or 135). This information (v / h / o) is added to the first photo in each series with a new pair of glasses on my weblog.

astigmaphile 26 Jan 2015, 18:00

I collect old glasses from thrift stores and use a trial lens set to neutralize them with. It isn't perfect, but is fairly close. What isn't completely accurate is cylinder axis. A lensmeter would be better.

astigmaphile 26 Jan 2015, 18:00

I collect old glasses from thrift stores and use a trial lens set to neutralize them with. It isn't perfect, but is fairly close. What isn't completely accurate is cylinder axis. A lensmeter would be better.

Cactus Jack 26 Jan 2015, 16:38


Here is something you can try using Sir Isaac Newton’s optics formulas, but I don’t promise very good results.

1. Get a pair of +1.50 or +1.75 OTC reading glasses, a tape measure, and a book or newspaper with small type.(the target) .

Your present glasses should correct your sphere and cylinder refractive error to 0.00 for distance. The OTC reading glasses will then make you slightly nearsighted by a calibrated amount.

2. Put on the reading glasses over your current glasses.

3. Hold the target about 12 inches or about 30 cm from your face and move the target away from your face until the type just begins to get fuzzy.

4. Measure the distance from your face to the target.

5. Divide the distance into either 100 cm or 39.37 inches.

You should get about +1.50 readers or about +1.75 depending on which reader you are using. If you get close to the power of the readers, you are ready to proceed with the other glasses in question.

6. Put on the test glasses with the readers over them.

7. Conduct the test again and note the distance where the text gets fuzzy. The difference in the distance you measured with your current glasses and the distance with test glasses will give you a general idea of the test glasses prescription. Each 0.25 step will cause a difference of about 9.5 cm or 3.75 inches.

Remember this is a crude test. The simple thing is to find an ECP with an auto-lensometer and get the prescription read.

Please let me know what kind of results you get. Remember, Cylinder messes everything up.


Cactus Jack 26 Jan 2015, 16:03


It means that she is myopic or nearsighted and probably cannot see anything very clearly that is more than 12 cm or 4-5 inches away from her face.

Trying to explain optical prescriptions without knowing some things about you is very difficult. Here are a few questions for you.

1. Age,

2. Education Level

3. Math or Science subjects you have studied

4. Have you ever had an eye exam?


NickM 26 Jan 2015, 15:46

Hi everyone, my girlfriend wears glasses full time. She didn't knew her prescription. Yesterday she went to the optometrist and her new prescription says:

Left eye: Sph -6.25 cyl -2.50 175

Right eye: sph -5.75 cyl -2.50 5

What does it means?


Lv2c4i 26 Jan 2015, 11:37

CJ: yes, they are my glasses. Mostly in the -3.5 vicinity, maybe 1 or 1.5 add and not sure about astigmatism? (And thnx for the replies).

gwgs 26 Jan 2015, 09:17

Lv2c4i - A rough way of doing it, and the only way I can think of doing it - depending on how many frames / pairs of glasses you have - is by taking a pair which you know the strength of e.g. a pair which you know have -9.75 lenses, and then comparing the subject pair to see if they are weaker or stronger. Try this with several different pairs and you should get an approx guide as to what they are.

Cactus jack 26 Jan 2015, 08:35


There might be a way, but it would not be very accurate and the procedure would only work with the individual wearing their most recent prescription. Could you provide the most recent prescription? Are they YOUR glasses?


Lv2c4i 26 Jan 2015, 07:33

Does anyone know of an easy at-home way of determining the strength of lenses? I have several pairs of older spex in drawers and such and am curious about their scrip--in comparison with the current ones? Some are blended lenses and others are single-vision.

Crystal Veil 23 Jan 2015, 01:39


like yourself, I'm happy with the fact that many Zenni frames remain in stock for years. My models always have enough choice if they prefer a payment in glasses. You might call the models my non profit group, only different.

The model with the "night blindness" was not my daughter but one of Nel's daughters. My daughter did occasional bits of modeling work but she is not interested in a photo shoot about glasses. A pity as her prescription is above minus ten. Nel's daughter did mention to the optometrist that she only had a problem with night driving. The optometrist did a quick measurement which was something like -0.25 / 0; cyl -0.25. Left it at that, saying that she did not need glasses. She then came to me and I checked her vision in the dark. It turned out that she needed glasses of -0.75 for night driving and I ordered them from Zenni with AR. She still has that pair but she never uses the glasses at daytime. In short: Up Zenni!

Soundmanpt 22 Jan 2015, 09:06

Crystal Veil

Yes for others that are just going in to buy glasses for them self most all of the on line retailers works fine for them because it doesn't matter that the glasses they are ordering is in limited supply and is a one time only option. In the case of Zenni if a frame is popular it stays around for a very long time. Foe example one that has been popular with many of my customers is #339121 and looks great on nearly every woman. In fact i just checked and as I speak I see that all 3 colors are currently "out of stock".

In the case of your model that was finding driving at night to be somewhat of a challenge due to her eyesight, it makes me wonder if she told the optometrist the problem she was having? I am sure when the doctor checked her eyes she probably tested out at 20/20, but something optometrists can't really determine is if someone has "night blindness"? Of course she isn't blind but it is just what they describe it as being. It just means even though her vision is fine during the day her eyes need some help seeing in the dark. You didn't say but I would bet that the prescription that worked well for her was -.50 or -.75 and with AR coating she can see perfect at night now. It is up to her if she wants to wear them other times during the day as well. In some cases this condition is an early sign of nearsightedness starting, but for some it never gets any worse. My best friends wife was prescribed glasses more than 5 years ago for this problem and her vision is still 20/20 but she wears her glasses at night when she drives.

If I recall didn't you fit your daughter with glasses a few years ago for driving, but she may have needed them for driving both at night as well as during the day?

Crystal Veil 21 Jan 2015, 16:08


thank you for the clear examples. Re the out of stock problem: I was lucky myself one or twice but more often not. This was all done by email so it may be handy for me to try the live chat as well. The idea simply never crossed my mind. I never tried any of their on line competitors as Zenni is always good for my purposes.

Interesting to read that you use sample frames with various prescriptions. My partner Nel once suggested that I could order a cheap pair with many different prescriptions. However, I have a trial frame and a set of trial lenses and these are quite handy for a check if a model needs to go to an optician for a proper eye exam. The trial frame & lenses are more precise than glasses with various prescriptions, although the latter option worked perfect in one case. The model in question had gone to an optician for an eye test after noticing that she did not see things clear enough when driving her car at night. The optician did a quick check and then told her that she did not need glasses. She then came to me and we did an extensive test with a dozen glasses and I was able to deduce the mild prescription she needed. She still uses these glasses (which I ordered from Zenni) for night driving.

You do a grand job with the non profit vision group. We don't have that in the Netherlands. Thanks again.

Soundmanpt 20 Jan 2015, 20:08

Crystal Veil

Well for example I keep a about 65 samples of women's glasses and 20 men's glasses. Of course some of them are considered unisex as well. That is what I often use in selling glasses and for the non profit vision group I am with.

One of the main reasons I recommend and prefer Zenni to some of the other on line retailers is because they operate much more like a an optical store. Many of the other on line retailers only get close out and discontinued frames, so that means many if not all the frames they sell are in a limited supply. So getting any samples from these other retailers was rather useless to me. But even with Zenni every so often they too will discontinue stocking a certain frame or at times be out of stock for a time. In my case I have came upon this happening as well. Someone will want a certain frame and when I go to place an order I see that it is either discontinued or out of stock. When this happens I contact "customer service" and explain that I have an order for that frame and ask them to check stock. Even though a frame may appear to be gone or out of stock I know they hold back a quanity in case a pair of glasses is damaged in shipment to a customer so they can replace it. They check to see for sure that they in fact have that frame is in short supply and e-mail me to let me know they will fill my request and that I should put in another frame in my order that is the same price and go into the "comments" area and tell them the actual frame I really want. This has always worked out well for me.

Another thing I use that comment area for is when I am placing an order for customers as well as maybe several new sample frames. I always get the sample frames with various prescriptions because we also use them for the vision group to help determine when someone has a need for glasses before getting them an eye exam. So because the rxs vary slightly I want them to understand that I didn't make a mistake in my order.

I understand calling for you would be quite expensive but try using the "live chat" as it works very well.

Crystal Veil 20 Jan 2015, 14:47


it's interesting to read about Zenni's customer service. I never called them because of the cost involved (they are in the USA). Can you give a few examples of your special requests to them and how they reacted? This would be handy in case I have a special request myself. Thanks in advance.

Soundmanpt 20 Jan 2015, 09:29

squint lover

I have always found the customer service people to be very friendly and helpful. I suggest you use their on line chat option before your order. I think they will tell you to note what you want for lenses in the "comments" area which I have used more than once when I have a special request.

Crystal Veil 20 Jan 2015, 03:55

squint lover,

it really depends on the size and shape of the frame. I ordered two pairs with a Rx of -15 from Zenni (e.g. 2611) and they did not need to make myodiscs. Lens thickness was about 14-15 millimeters but the frames could be closed neatly. On the other hand I also ordered several frames with a Rx of -12 and the lenses in some of these were a bit like myodiscs. There was no additional charge for their extra work. All these glasses were fitted with their standard 1.57 lenses. The only real myodisc pair I ordered from them was -19.25 / -19.75, 1.67 lenses. Again, no extra charge. If you want to see a few examples, click the link below. Good luck!

squint lover 20 Jan 2015, 02:42

Does any of you guys know just how thick lenses can be when ordered from Zenni before they make them myodiscs? I love my GOC myodiscs, but I would also like some more "normal" glasses when doing GOC.

Andreas 19 Jan 2015, 11:31

Kiki, so what glasses do you wear and how often or where to go?

Just curious.

Best regards, Andreas

I.m a glasses wearer myself, needing -4.5

Kiki 13 Jan 2015, 18:49

I was just curious! I'd order them in the full prescription! I've been obsessed with glasses since I can remember, I'm always learning more!

Soundmanpt 13 Jan 2015, 16:58


Oh, okay I thought I recognized the name. I'm not sure what you mean by not ordering your sister her glasses in her full prescription? I assume you might mean by leaving off the astigmatisms maybe? Or do you mean reducing her contacts some to say around -3.00 or something so your able to wear them? The answer is easy, she would be slightly under prescribed making things in the distance a little blurry for her.

Kiki 13 Jan 2015, 16:28

I've ordered from them many times and am ordering again soon! I'm the one that has posted in "Induced Myopia" cuz I am able to wear glasses/contacts with the same prescription as my sister but don't need them! I'm jealous that she actually needs them so I get to pretend :) Just curious, how much of a difference would it make for her to not use the full prescription? I wouldn't intentionally order them that way, just a curious glasses girl ;)

Soundmanpt 13 Jan 2015, 08:52


Yes just as I thought. So when you order her glasses you want to use the full prescription numbers. If you were ordering her contacts then you would ignore the CYL and axis numbers.

Cylinder and axis is only needed if the patient has astigmatisms and not everyone that wears glasses has astigmatisms.

Have you ordered glasses from Zenni before? If not i think you and her will be pleasently surprised at the quality of the glasses.

Brian 13 Jan 2015, 08:21

TheBrit, I do have rimless frames as well.. My prism is not quite as strong as yours, but with high index lenses, I did not have any issue with a rimless frame. My lenses are pretty much flat fronts.

thebrit 13 Jan 2015, 05:07

Frank,Jaybee,& Brian,

I cannot but agree that the use of prism to deal with double vision, headaches etc is not a solution people should fight against. The benefits of using prisms IF NEEDED far out weight the disadvantages as we all agree on.

Yes the steady increase of prism over the years is a concern at first, but as the vision finally becomes more stabilised and so good you forget this, & the fact that the lenses start to get thicker.

As you have commented, remarks about the appearance of your glasses are seldom made, in my case never.

My only regret is that I am unable to find someone who is prepared to make rimless glasses for me due to the outer edge thickness of 9/10 mm. They all say they cannot get fixing screws long enough? Any guidance on this would be appreciated

Kiki 12 Jan 2015, 18:42

This is what her RX reads...


OD -3.75, cylinder -.25, axis 180

OS -4.00, cylinder -.25, axis 160


OD -3.75

OS -4.00

I think it makes more sense now but just wanted to make sure before I ordered them. It doesn't seem like it would make much of a difference but I'm sure she wound notice! Do most glasses prescriptions typically have a cylinder and axis?

Soundmanpt 12 Jan 2015, 17:29


Okay let me explain what your looking at. There is nothing wrong with what her doctor gave her. I really wish that you had also included both her glasses prescription as well as her contact prescription. That would have helped things, but even without it I think i can clear things up for you.

If you look I bet her CYL is less than -.50. This is important because when the CYL is less than -.50 the doctor will almost always not use it for contacts. Now if her CYL is -.25 then her doctor will ignore it completely. If it is -.50 then most doctors will just increase her SPH by -.25 more than what her glasses prescription is. In other words they feel like by increasing the SPH is compensating for the lack of CYL.

Now the reason they do this is really to benefit your sister. If they were to give her the exact same prescription as her glasses then she would need special contacts called "toric" and they cost about 3 times more than the contacts he is recommending for her.

So don't worry just order her glasses just as her prescription reads for glasses and you and her will be fine.

I do suggest that you include the option for the AR coating (anti-reflective) even the cheapest one ($4.95) is fine.

Good luck and any further questions feel free to ask.

Kiki 12 Jan 2015, 16:15

How come a doctor would write out a script for glasses including cylinder and axis but leave it off for contacts? I was going to order glasses for my sister on Zenni and she sent me a picture of her written prescription and that's what it shows! I asked if she had astigmatism and she said no so I'm confused!

Brian 12 Jan 2015, 15:27

Jaybee/The Britt, I have prisms as well, but mine are Base In, 5 in each eye.. My prescription is in the -5 to -6 range and with high index lenses, the inner edges of the lenses of my glasses are 7 to 8 mm thick. With them being thick on the inside its not as noticeable as it would be if the prisms were base out. Like you, I have seen my prisms increase but they have started to stabalize. At age 31 in 2010, I started with 2BI in each eye.. 2011 went to 3, 2012 to 4, 2013 to 5 in each eye.. At my last appointment in March 2014, they actually held steady for the 1st time. I'm 36 now. Without my glasses I see double and can not fuse an image.

Stingray 11 Jan 2015, 14:21

Why are biconcave lenses prescribed and to whom? What are the benefits and what are the alternatives to this type of lens?

jaybee 11 Jan 2015, 14:14

thebrit...i too have prism in my prescription, i am at present bout 5 b/o, i also have some rimless frames and guess the outside edge is about 10 / 12 mm, i quite like this look and no-one has ever mentioned they look thick. like you my prism correction seems to be regularly increasing but at each new lease the visions so much better than before, my optician seems to think it will level out soon, i too see double without glasses on and also suffer excruciating headaches if i remove my glasses for more than about 15 least i see really well with glasses and think the trade off of permanent need for the prisms is better than suffering double vision

thebrit 11 Jan 2015, 09:07


I understand your mail very well, & your problems surrounding double vision/prisms. Without my glasses I only have double vision, & like you to see a single image, I too close one eye. When I started with prisms, like you, I was wary of the dependence of prism, & with regular increases, I didn't see an end to the increases. Now at 10 base out I have excellent vision, which has been stabilised now for over 2 years. I even think it will remain so at my next control. Of course the downside of strong base our prism is lense thickness, but as I have said before this really doesn't bother me as with careful choice of frame it is not so noticeable. I do not regret being prescribed prisms as after years of uncomfortable vision, I now feel fine with my glasses. I am also aware that there is probably no way of going back.

Frank 11 Jan 2015, 04:53

Hi thebrit,

with your prescription can you still fuse the images of both eyes or do you see permanently double (or where is the threshold in terms of diopters)?

I have a similar spherical prescription (+2.5) and wear 3 prisms BO in each eye. But I am slowly getting problems to fuse images without glasses. Even though I can fuse it the image is becoming increasingly blurry - much worse than closing one eye. So I mostly tend to close one eye when doing anything without glasses. Although I know I need higher prisms I want to delay it as long as possible to avoid getting permanent double vision.

I am wondering because your script is so much higher than mine.


thebrit 11 Jan 2015, 03:04

Ben, you must understand, that all glasses are custom made to each individuals vision requirement. This is even more so if a high prism level is added. Anyone with high prism will need to ensure all the factors are correct if they are to have good & trouble free vision.

I do not sell or pass my glasses on to others as it would not be doing them any favours...sorry

ben 11 Jan 2015, 01:57

Hi thebrit I too wear glasses with prisms do you have any for sale with 10 base out prisms

thebrit 10 Jan 2015, 07:08

I have worn glasses for nearly 50 years, since my late teens. My prescription is +2.5 with some astigmatism & some add to assist reading. In more recent years I found I was getting double vision, but my optician was reluctant to prescribe prism, because of the possible dependence on prism.

However, she finally put me into prisms which over a few years of increases resulted in 10 base out prism in both eyes. This has now stabilised at 10 base out for just over 2 years. I have always chosen standard CR39 lenses for better visual performance & of course price. Although it meant my lenses were 10/11mm thick on the outer edge. I do not see this as a problem because with the right choice of frame they can look ok. Anyway good vision comes before vanity!!

I have recently tried high index lenses so as to reduce the edge thickness so I could possibly buy rimless glasses next time. However I find the high index lense causes more reflections and less field of vision compared to the CR39. Has anyone else had this issue with high index lenses. Does anyone have comment on how a rimless glasses would look with a 9/10 mm edge thickness?

Likelenses 06 Jan 2015, 00:05


Oh,I would say that in six months that she will be ready for an increase.

william2 04 Jan 2015, 14:48

Hi Likelenses

My partners glasses arrived yesterday she so happy with the bifocals so much easier to see with them both pairs are lined bifocals and she had no problems getting used to them the stronger pair she says is much better for seeing distance and sewing the other pair is good for computer and reading .so I supose she has glasses for 3 differnt distances now.

Will keep u updated,when do u think she should go for a retest


Likelenses 23 Dec 2014, 18:00


Some people that are myopic have slow focusing from far to near,and vise versa.

In her case it is perhaps the fact that she is newly corrected,and may improve after a time in glasses.

As far as increasing prescription,yes she will have some increases most likely until age 22 or so.Actually it would be good if her right eye had smaller increases,and the left larger,so that there is not that huge difference that exists now,especially in the astigmatism.Often times nature will want the two eyes more equal,and that will happen.

I am curious as to how long she feels that she needed glasses.

william2 23 Dec 2014, 05:15

Hi Likelenses

Thanks we have ordered 3 pairs now one with bifocals with the prescription she has now with the 100 ADD and one pair of bifocals with the .75 extra power and a pair of reading glasses with the prescriptin you gave us we have the PD as well.

As she is only 19 do you think her sight will keep getting worse for a few years yet. It is so nice to see her not squiting and her right eye turning in she looks so much pretier now weaaring glasses,why do you think she has problem changing from distance to close vision, she is quite excited about getting bifocals as well so i hope it helps her.

will keep you updated when they arrive

Thanks william

Likelenses 23 Dec 2014, 03:06


In ordering you will also be asked for the distance between her pupils,called PD.

If that measurement is not on the prescription that she got from the receptionist,you could call them and get it.

You can measure it yourself,but it would be best to go with the one that her optician did.If she got the glasses from an optician,located in the same building as the doctor,ask the optician ,rather than the doctor.

Also go with the cheapest lenses,they are actually better in optical quality,and you save money.

Likelenses 23 Dec 2014, 02:50


If she wants just glasses to read and sew with then order,

Rt -.50 -1.75 cyl 82

Lt -.25 - .50 cyl 113

If she wants bifocals,go with her present Rx,but then when you get to the box marked add type in +1.00 for each eye.

If she wants to go with the extra -.75 in the right eye, as the assistant said she needs then,stay with the above numbers for the left eye, and use these for the right.

Rt -1.25 - 1.75 cyl 82 for the reading glasses OR

Rt -2.25 - 1.75 cyl 82 + 1.00 Add if she wants the bifocals.

william2 23 Dec 2014, 00:49

Hi Likelenes and Soundmanpt

how should my partner write her prescripion for just reading glasses when she orders on the internet.


william2 20 Dec 2014, 15:50

sorry last post was from me

 20 Dec 2014, 15:42

Hi Likelenes and Soundmanpt

We Thank you both for your help and interest.

My partner is 19 years old.

Lunch time today she took your advise and went back to the eye dr to find out more about what he had said,He was on holiday but his assistant got her records out to check her prescription .

It turns out that after he had tested her distance vision he then checked her close vision and discovered she had problems changing from distance vision to close vision, that was why he said she should have 2 pairs of glasses one for distance and one pair for sewing and reading not as she thought he meant 2 pairs with the same prescription.when she asked for a copy of her prescription the reseptionest gave her the prescription for the pair she picked up not her full prescription which included a ADD of 100, also his assistant recheck her vision and said she must come back In 6 months for a recheck or sooner if she was having a problem again as he thought she should have had .75 more in her right eye.

Tonight we have looked on the Internet as Soundmanpt suggested and she wants to order a pair of bifocals with the 100 Add also the glasses are so much cheaper so she want a pair of reading glasses as well should she just take 1.00 off of the sph

Many thanks

Likelenses 20 Dec 2014, 02:09


I agree with all that Soundmanpt has said.

I am curious as to her age,as that is a hefty Rx especially for a first one.

Soundmanpt 19 Dec 2014, 16:39


Just what I thought. So in that case she may want to hold off until his return and get her full prescription including an add so she can order bifocals if she wants at that time. Or as he suggested since she has one pair for distance already that seems to be working and should even help her close vision as well because like I said astigmatisms are also a factor in close vision as well as distance. But she can order a pair of single vision reading glasses once she knows what he wants her to wear. But include in that her astigmatism numbers as well because they are critical as well to her seeing close up. And of course you can order those in line if you wish. But for now you and her just need to be patient and wait for his return to do anything. Remember her vision now is much much better than it was a week ago just with these glasses. She is in no way doing any harm in wearing her glasses just as they are until he returns and then she can decide what she wants to do. If it were be I think by getting her glasses from Zenni ( you will save so much money that you maybe better off getting her a pair with just for reading single vision and get her a pair of bifocals if she wants to learn to wear them so she won't be fooling around switching glasses all the time when she wants to see to read something. Her single vision glasses for reading she can get for around $25.00 and her bifocals around $55.00.

william2 19 Dec 2014, 15:04

Hi Soundmanpt.

Thanks for your long and detailed reply.we have learnt a lot .

My partner has just told me after the eye dr had finished testing her eyes he said your eye sight is very bad u need to wear glasses all the time now do you want a second pair for reading she thought he meant her to buy two pair with the same prescription, but now she thinks he meant to have reading glasses as well as she found it harder to read the small card he gave her to hold untill he put somthing in front of the trial was dark in the testing room and after taking the trial glasses of she said she could not see much and was a bit confused .

The eye dr is now way till after the new she will see how she manages in the next 2 or 3 days before ordering a 2nd pair with this prescription in. If she had reading glasses as well would it be just the SPH that is less

Many thanks


Soundmanpt 19 Dec 2014, 14:18


My predicting that she would very quickly find that she needs to be wearing her glasses full time was really quite easy because of her prescription. There is little doubt that she has needed glasses for some time and sadly just just didn't realize it because she had nothing to compare her eyes to. Most people for a while just assume that everyone is seeing the same as they are.

As for as ordering bifocals I really think she should hold off for a while before making that decision. But I do think now that she has found out that she can't see anymore, at least very well anyway, she does need to get a spare of glasses just in case something were to happen to the ones she is wearing now. Like she has found out going back to not wearing glasses is no longer an option for her and she knows it. But she has only had her glasses a couple of days so her eyes are still adjusting to them fully and it might take more than a week or so before her eyes are completely adjusted to them. I'm sure she is still coming to terms with her close vision and it may still be blurry which is why she is thinking bifocals will help. But the truth is her eyes really shouldn't need bifocals based on the prescription you provided. I think if the doctor make a comment about bifocals it actually could be that she maybe has a small need for an add but he decided to ignore it for now, because the prescription you provided shows no reason for a bifocal now.

I urge you to try and convince her that in a short time her vision with her glasses is going to be very good and she is going to be much happier wearing single vision glasses than bifocals. If after a few weeks she is still insisting on wanting to try bifocals then go first and talk with her doctor to see if he has in her chart that she mat at some point require an add and have him rewrite a new prescription including the correct add. That way you or I aren't making a guess at what she will see best with and maybe we are both wrong.

Look at this way she has gone all this time without glasses when she really needed them. Now she has glasses that is already showing her how much she needs them and she is now pushing for something that really isn't going to make her vision any better and actually will make it even harder to adjust to. Now is the time she needs to slow down and give her eyes a chance to adjust.

William2 19 Dec 2014, 01:52

Hi Soundmanpt

You were correct she needs her glasses full time already.

When she woke this morning she went to make breakfast half way there she turned around and said I need my glasses I really can't see any more without them I been so stupid not getting them before I did not know how bad my eyes were.

She just texted me from work boss said thank god you got glasses at last now I hope you see customers better .

She said she is so used to holding cell phone close to read it that she finding hard to get used to holding it so far away and she needs to hold the needle to far away to get the best vision.

As she says she MUST have a spare pair she wants to try a pair of bifocals as well. She looked on the Internet at coffee break and found that she can order a ADD from .50 would that be best to try first as they very cheap



Soundmanpt 18 Dec 2014, 19:59


Your welcome for the help and I am glad I could be of some help. I will try and answer more of your and her questions about her need for glasses.

She is somewhat correct in her thinking that her vision wasn't as bad before she started wearing her glasses as it is now when she takes them off. But the truth is what she sees now when she takes her glasses off is her real true vision. Before she got glasses she was only compensating for what she was missing mainly with her brain and not her eyes. It is very normal and nearly everyone feels the same way as she does. It's just a part of adjusting to them and without them now. In other words her glasses aren't making her eyes worse by no means even though over the years we have all heard someone make the claim that wearing glasses ruined their eyesight, which is completely untrue.

I think for the time being it might be best for her to first let her eyes adjust to the glasses she has. Honestly I think her prescription is just fine for single vision glasses and she might find bifocals to not only be more expensive but also harder to use than single vision glasses. But if you and her want to give them a try I would suggest she only get the weakest add possible, +1.00. But for now her near vision is going to take a little bit of adjusting either with or without bifocals due to her astigmatisms.

william2 18 Dec 2014, 13:09

Hi Soundmanpt

Many thanks for your help it explans a lot.

She say see feels nearly blind now when she takes them off after only half a day,and wonders how she managed before.she is sure she could see more without her glasses than she can now when she takes them off.

When she had her test the eye dr checked her for close vision and she told him it was not as clear close up as distance.she said to him she did a lot of sewing.he said if it was a problem they she could get bifocals as well but they cost a lot more.

She was wondering if it would be worth getting a pair of bifocals off the internet to try if so what ADD would you sugest. As she feels she is now already dependent on glasses she wants to get a second pair and is happy to wear them all the time.

Many thanks again it has been a big help

Soundmanpt 18 Dec 2014, 12:24


Well not exactly but as you can see she is just slightly more nearsighted in her right eye than her left by just -.25 . But her astigmatism is far more in her right eye than her left. Now this is a bit primitive but to get a close idea take half of her astigmatism numbers for each eye and add that to her distance numbers to get a little closer. So her right eye would be about -2.25 or -2.50 and her left eye would be -1.50. But still a sizable difference.

 18 Dec 2014, 11:18

Hi Soundmanpt.

You said my partners right eye is considerably worse than her left eye is that because if you add the sph and cyl together it is -325 for the right eye and only -175 for the left eye.Is -175 cyl a lot

Forgot to say its her first pair.

Thanks again

Soundmanpt 18 Dec 2014, 11:05


I am not at all surprised at how much better she can now see with her glasses. Her eyes are still adjusting to them and will be for a few days to come even though she is much more able to see so well already. Her prescription is mainly for distance with astigmatisms which effects her vision at all distances, so I think as her eyes get more adjusted to her glasses she won't be holding the needle and thread as far away.

My best guess is that she will need some increase after maybe 6 months or a year. Her eyes were badly strained when that usually means she was under prescribed as a result. Now with her wearing glasses and her eyes becoming much more relaxed her next exam should get her really close to her full prescription.

It is always hard to predict how much change may occur in her vision and a lot depends on her age. I assume she is past 20 years old so once she gets her full prescription her eye may not change much after the next year or so.

The good thing is she doesn't seem to mind wearing glasses since they clearly improve her vision so much.

william2 18 Dec 2014, 10:35

Hi Soundmanpt.

We picked up her glasses lunch time today she is so shocked at how much she can see now; she had not relised how bad her eyesight was.The eye doctor said she should wear them all the time.After she got them we went shoping for about 2 hours,she was so pleased to see so well, we then went for coffee while we waiting for it she took her glasses off to look at them and said i cant see acroos the room without them the eye doctor was right I must wear them all the time I should have got glasses a long time ago.I said yes I have been telling your for months you needed them As soon as we got home she wantted to see if it better for sewing she said she could now see to tread the needle but had to hold it further away.Why is that? Is there anything we can do about it?

How soon should she go back for a check up, do you think her eyes will change much now she has glasses.

Thanks for your help

Soundmanpt 18 Dec 2014, 09:33

william 2

I assume if she just got her eyes examined she doesn't have her glasses yet? Most likely if she picked out her glasses they will be ready for her in about a week or less.

She is going to be shocked at just how much difference they will make to her. You didn't say but you made it sound like these are her first glasses? If in fact they are you need to start getting used to seeing her wearing them nearly if not full time. Her right eye is considerably worse than her left eye which isn't all that good. She has a rather high astigmatism in her right eye which maybe why her eyes can't focus enough to allow her to thread a needle.

Once she gets her glasses you may want to provide an update.

william 2 18 Dec 2014, 03:39

My partner has been complaining that thing looked very brured in the distance and she had a problem seeing cell phone also could not see to thread a needle to sew and got a lot of headaches , and I could see she looked crosse eyed and right eye turned in.

She had a eye test today this is the prescription .

R -1.50. -1.75. 82

L -1.25. -50. 113

Will it make a big difference for her.



lucy 15 Dec 2014, 14:03


for the moment is ok. only when very tired turnes a little. thanks for help

Soundmanpt 15 Dec 2014, 09:07


Now that you have your new glasses let keep us informed as to how your eyes feel wearing them. That is the real test as you know.

lucy 14 Dec 2014, 09:32


i think the opticianwas trying to sell. i got it anyway. thanks. i hope its not going to get worse.

Likelenses 14 Dec 2014, 00:05

High Myopic

There is an old saying, "You only get what you pay for".

Go for the 48 diopter pair.

High Myopic 13 Dec 2014, 19:03

Those microscope reading glasses seem like they should be more like 35 dollars.

Likelenses 13 Dec 2014, 18:50

High Myopic

Just go for it,spend the money,it's only money.

High Myopic 13 Dec 2014, 17:44

I want to buy a pair of these Microscope Spectacle glasses to wear myself. I found them on amazon and eBay but they are still very expensive.

These are 74 dollars and

These are 120 dollars.

Can I find a pair under 50 dollars? I want to remove the blacked out lens and put in my rx in that lense instead.

Soundmanpt 13 Dec 2014, 11:52


Who suggested that you wear small frames? No, you can wear whatever you feel comfortable wearing. The frame size has no effect on how you see with your glasses.

lucy 13 Dec 2014, 09:54

hi. also changed the frames

i was suggested smaller ones? do the frame make any difference cause i would like also a pait of bigger ones?

Soundmanpt 13 Dec 2014, 09:24


I'm glad that reducing your prescription and in creasing the PD seems to be of help, but in order to keep your eyes aligned properly and in a way train your eyes you must wear your glasses completely full time if you weren't already. Without your glasses being on your eyes will revert to the way they were within just a few minutes.

lucy 12 Dec 2014, 08:20

hi. thanks again everybody. i got -1.75 lenses in each eye and increse the pd from 58 to 62. and its working.

Cactus Jack 12 Dec 2014, 07:01


Increasing the PD has the same optical effect as adding Base In prism to your glasses, but changing the PD only works for relatively small amounts of actual prism.

There are 6 eye positioning muscles on each eye which move the eye either left or right, up or down, or obliquely. They work in opposing pairs under the control of the eye positioning system in your brain. From an engineering point of view, the system to coordinate the motion of the eyes is an amazing “Open Loop Servo System”, which means that the control system does not know the exact position of each eye, but uses the images from the eyes to determine what adjustments need to be made in eye position to fuse the two individual images into one hopefully 3D image.

For lateral motion (left or right) the system uses the Medial Rectus (inside) and the Lateral Rectus (outside) muscles. If the system is working correctly you can move your eyes left and right, up and down, and obliquely in a coordinated fashion and you can converge your eyes to keep close images fused, however there is no visual need for the eyes to diverge beyond the central axes of vision to be parallel for distance. There is also an interesting two-way connection between the eye positioning system and the focus control system. The act of using your ciliary muscles to increase the plus power of your crystalline lenses so you can focus close will also cause your eyes to turn inward or converge and if you cause your eyes to turn inward (cross) it will trigger your ciliary muscles to increase the power of the crystalline lenses. Generally, you are not aware that this is taking place. The strength of the connection between the Eye Positioning System and the Focus Control System varies with individual and it is possible to train the systems to modify the convergence response.

We often read here of members wanting to induce Myopia and I have explained the two types of myopia and their sources. Pseudo Myopia involves the ciliary muscles and crystalline lenses and too much minus in your glasses will be corrected by your focus control system adding PLUS to your crystalline lenses to neutralize the excessive minus. This can trigger the convergence response, but most people can overcome that. I suspect that your optician decided to reduce your sphere prescription a bit in addition to increasing your PD to reduce the convergence response and train your outside muscles and the control system to alter the relaxed position of your eyes and ideally train the systems to NOT converge unless your actually want to focus close.

The reasons for using any prism correction are very complex. The general terms are Strabismus or Muscle Imbalance. Eye positioning problems can occur in 3 places, the eye muscles, the nerves from the brain to the eye muscles, and in the brain. Unfortunately, we only have two ways to correct the problem and fuse images for the patent. Use prism in glasses or muscle surgery, even if the actual problem is elsewhere. Prism or PD adjustment is by far the most simple solution and it has the added advantage of being easily reversed or changes. Muscle surgery is harder to reverse or change.

You expressed concern about becoming dependent on prism. That can happen which is one of the reasons Eye Care Professionals (ECP) are often reluctant to prescribe full prism correction. Often people who need some prism correction are concerned that others will notice that your eyes do not point straight ahead. Ophthalmic Prism is prescribed in Prism Diopters NOT degrees of prism. The confusion is often caused by the use of a tiny triangle after the number that is often mistaken for the tiny circle used to indicate degrees. ONE Prism Diopter will cause or correct 0.57 angular degrees of eye positioning error. As far as being noticeable by others, you have to get up around 10 diopters of prism before anyone but an ECP or OO would notice that you have prism in your glasses. For Base In prism, the extra thickness will be near your nose and the outside thickness of your glasses will be less.

I hope this helps you understand what is happening. Your ECP is trying to help you with the minimal correction he/she can, but the only way to tell if it works is to try it. Hopefully, if this solution doesn’t work, they will remake your glasses without charge.


lucy 11 Dec 2014, 06:56

thanks for the replies. i was suggested to increase the pd. not decrease. is that right in minus lemses.? what i find strange is that when i close my left eye the right eye is not turning behind the lense. omly when they are opem together

daffy 11 Dec 2014, 04:13

Changing the PD is effectively inducing prism. If you're mathematically minded, you could work out the desired prism by crunching the numbers. Look up Prentice Rule. The higher the Rx the less decentration required.

daffy 11 Dec 2014, 04:12

Changing the PD is effectively inducing prism. If you're mathematically minded, you could work out the desired prism by crunching the numbers. Look up Prentice Rule. The higher the Rx the less decentration required.

aubrac 11 Dec 2014, 00:52


I had 4 degree base out prism added to my -4.50 glasses and it made reading easier and generally less fatigue.

Didn' t find it at all addictive but believe it can be at higher levels.

 09 Dec 2014, 20:20

Base out prism will make you so cross eyed you will be able to see out of your ears.

antonio 09 Dec 2014, 16:58

I read here, Lucy,

that prism glasses can make you dependant on wearing them

to avoid double vision in only hours or days you wear them,

so be careful in starting this, if not necessary, please

best regards, antonio

lucy 09 Dec 2014, 12:32

thanks for your reply. i dont mind wearing glasses full time. i am only concerned cause i read some aboutsome situations where bo prism caused even more turn in. what do u think?

Soundmanpt 09 Dec 2014, 11:19


You asked if you would become dependent on your glasses? And the answer is in order to try and correct your eye from turning in you will really need to wear your glasses every waking minute for anything to work. If you in fact get prisms they don't make contact lenses for prism and after a while if you try and go without your glasses which at -2.00 or even -1.50 should be rather hard anyway, but now you can add possible double vision and headaches to the list.

And instead of prisms the idea of trying to force your eyes over by spreading the pupil distance apart thus causing your pupils to want to try and find the sweet spot of your glasses may work, but again that is something we can't answer in here and really needs your doctor to determine the best option for you. I assume that optician might be thinking by reducing your prescription some may help then if your doing close work. But even with a weaker prescription I can tell you whatever your doctor decides as the best option either way your going to be told that you need to start wearing your glasses completely full time in order to try and pull that eye over in place. But like i said really even -1.50 is enough that you really should be starting to keep your glasses on even if you didn't have this eye problem at all.

lucy 09 Dec 2014, 01:59

hi. an optician suggested that he shouls lower a little the minus -1.5 in stead of -2 and increase the pd. do u think its going to work?

lucy 08 Dec 2014, 08:41

thanks for your answer. should be based out to avoid the turn in? will i get dependent on them?

Soundmanpt 08 Dec 2014, 07:33


It would seem so, but your eye care professional would be know for sure since he or she would be able to examine your eyes to determine what might work best for you but assuming your past say 10 years old I think prisms would be recommended to you.

lucy 08 Dec 2014, 05:08

hi. i had strabismus as a child. now i need glasses for myopia -2. the problem is that my right eye turns a little inward. how can i avoid this. so the eyes would be aligned? prism out lenses? thanks

Likelenses 05 Dec 2014, 00:48

Do you want to wear REAL GLASSES?

Actually glass lenses do give better acuity. I have tried them.

Brian 01 Dec 2014, 12:54

Here is some info on the anti-fatigue lenses.

guy 01 Dec 2014, 09:25

I've been prescribed with astigmatism, as an add on for my lenses, they said i would be benefitted to add on anti fatigue and anti glare. what is this anti fatigue lens? I do not have an add on my prescription

antonio 28 Nov 2014, 13:31

yes they can High Myopic and probably will after only some hours of wearing them !!!


EyeTri 28 Nov 2014, 08:49


Harbor Freight sells a nice little ultrasonic cleaner for $34.99. I use it quite often to clean up glasses that I get from eBay. It does a really good job. Good for jewelry too.

You can find it at:

John S 27 Nov 2014, 20:11

Sometimes the cleaning liquid can give the nose pads a hard time, depending on the material that are made out of.

Crystal Veil 27 Nov 2014, 17:03


I had fine results with a simple ultra wave machine sold to me by a German chain called Fielmann. They use it in their shops and its price was only 15 Euro. The results are far better than any hand work.

Ellie 27 Nov 2014, 16:35

Question about cleaning glasses:

Not sure who else has this problem, but the frames of my glasses are slightly see-through (rather than an opaque color) and I can see that the lenses inside of the part with the frame are kind of dirty.

Does anyone have tips on how to clean the part of the lenses that are covered by the glasses frame thoroughly?

I also find that thickness of the lenses on the side of my glasses can also be an issue, but I'm usually able to clean the sides pretty well with a microfiber cloth.


High Myopic 14 Nov 2014, 07:35

I have a friend in Israel making me a powerful pair.

Likelenses 14 Nov 2014, 02:57

High Myopic

No,just order the most powerful ones you can.

High Myopic 13 Nov 2014, 21:46

Can your eyes become dependent on base out prism glasses?

Soundmanpt 09 Nov 2014, 23:05


Yes that is true. I wonder what is up with er these days?

Likelenses 09 Nov 2014, 22:29

We have not heard from the bespectacled Clare lately.

Likelenses 09 Nov 2014, 22:27


Come around more often.

guest 09 Nov 2014, 18:54

What Happened to Ellen....


enjoying the biconcaves?

waiting !

guest 02 Nov 2014, 06:43

To Ellen....

the soooo.... Ellen and you? was simply a comment asking for your opinion on the subject. Feelings are the same, glasses and "kindrid spirit" open the door, but it's what behind that counts... by the way, brains are #1...

Remember there are 24 hours in a day and the erotic spirit only accounts for a very small portion of it :)


Ellen 01 Nov 2014, 08:51

No I don't have a physical attraction to others in strong glasses at all. There's no erotic component there whatsoever. I suppose there's an element of kindred spirit with someone with strong lenses, a kind of mutual understanding but that would be way down the list when choosing a suitable partner for me.

guest. What did you mean by "sooo Ellen,and you"?

guest 30 Oct 2014, 18:54

Hello... for Ellen..

My -19g/f was not that glasses oriented, even though she made fun of her biconcave cokebottles..

However, I met a lady (about a -13 or so, in cr39's big frames of the 80's) who - when we went out again, while intimate said, :I have to admit something, I was first attracted to your glasses (at that time -11 and astig)- then liked you for your brains and personality. I didn't know what to say-I was shy. Later, after dinner we went to the movies with another couple and she whispered, "Can we sit in like the first or second row, I really can't see even with my glasses". I was just staring to see my next g/f.. so I didn't follow up... guess, shy and remembered what the parents of my -19 g/f said, "the children will come out with telescopes lol"

Sooo ellen, you??

Likelenses 30 Oct 2014, 14:51


Perhaps you are right about sowing the seeds of an obsession.

My earliest remembrances of strong glasses is a lady friend of my parents that would baby sit me.I was fascinated by her strong lenses but I don't think that I ever grabbed them.

They were rimless,with glass lenses,and really thick.

Later in life I would only see her occasionally but then too I was attracted to those glasses.I would try to imagine how it would be wearing them.

In school I was always more interested in the girls that wore glasses for myopia.And most girls that I dated wore minus glasses.

Do you find yourself being attracted to men that wear minus glasses,and if so do you like higher prescriptions on them?

Now that I wear fairly strong glasses,I am attracted to women that have lenses as strong or stronger than mine.Perhaps " birds of a feather "syndrome!

Of course there are many other,and more meaningful attributes that I look for in a woman,but strong glasses are certainly the frosting on the cake.

I am single and still looking for my bespectacled best friend,and wife.

Ellen 30 Oct 2014, 13:30

Mine didn't break thankfully but I couldn't see a thing and had to ask him as calmly as possible to give them back. I said something along the lines of "Auntie Ellen needs those to see, give them back sweetheart". It got me wondering afterwards if innocent incidents like that in a child's formative years can sow the seeds of an optical obsession later in life.

Likelenses 29 Oct 2014, 17:33


When I was at -9.5 a similar thing happened with a brand new pair of rimless.

The kid threw them down,and the left lense broke at both screw holes.

First off I had trouble even finding the glasses,as I could not see,and when I did, I had to put on the one lense,that still had the nose,and ear pieces attached,to locate the other broken lense,and ear piece.Worse yet I had to drive one eyed for two hours to get home.Then had to wear a old pair of -8.00 for several days,until the -9.5 ones were repaired.

Are you still enjoying the new sexy bioconcaves?

You said that your peripheral vision is better with them.I will have to see if I can have a pair of bioconcave made up in my -10.5 Rx,and see if my peripheral is better than with my present flat front lenses.

Ellen 29 Oct 2014, 15:35

Looking after my sister's kids today and her son, ever the adventurous one noticed I had new glasses and promptly grabbed them off my face. At least as they're not my kids I get to give them back. I'm sure myopic mums have to put up with this sort of thing a lot.

Patrick B 28 Oct 2014, 12:48

Hi Jeff --

I've got a couple of different types of glasses:

1) I have several of the Shape #2 (Bi-Concave) which are crafted from 1.9 glass and have a prescription of OD -24.00 and OS -24.75. They are full aperture in a 45mm frame. The OD lens has -2 of the prescription in the front and -4 in the OS lens. I also believe the front of the lens is of an aspheric design which gives me pretty good peripheral vision. The lenses are still pretty thick at approx. 12mm even with all of the clever beveling the lab does.

2) I also have a new pair of myodisc glasses which are bi-concave with approx. -1 in the front and the balance in the 20mm bowl. My new prescription is OD -25.25 and OS -25.75. I guess they are closest to #5 in basic shape but the lab also ground down the carrier portion (which is negative per my request) making the carrier almost flat. They're fairly light and the bowl doesn't really show that much when I've got them on. Vision is good and I have surprisingly good peripheral vision.

Maybe you should find out if your lenses are aspheric which are great for increasing peripheral vision. My vision is around 20/30 or 20/40 which is enough to drive. I also have contacts which provide 20/20.

High Myopic 27 Oct 2014, 18:27

Jeff R, can I email you about my 11 pairs of myodisc glasses that I like to wear? I recently got a box of 11 pairs of high myopic glasses in the mail that I really like wearing sometimes. I would love to see pics of your -26 eyeglasses. My email is I love wearing very very strong eyeglasses.

Jeff R 27 Oct 2014, 13:28

Hi Patrick

I was reading some of your posts about your lenses and I'm a little confused about their appearance. I looked on under "custom optics, popular lens shapes, high minus power lenses. Are your lenses, "#5 Blended Myo Concave Front"? I know blended bowels are hard to measure but approximately what is the diameter? What index are your lenses? I am -26 both eyes and wear 1.9 index full aperture plano front lenses. The optics are very poor except in the very centres of the lenses so for the most part I don't see well unless I keep turning my head. I'm looking for a better alternative. Thanks

Patrick B 27 Oct 2014, 11:20

Hi Ellen --

I've had biconcave lenses for many years and think they're the only real option for high myopes. The concave part in the front contains part of your prescription, usually no more than -6, which reduces the thickness at the back. However, this means that the lens usually sticks out a bit from the front of the frame which negates the reduction in thickness at the back. I think the main reason for biconcave lenses is that the refractive capabilities of the lens are moved a couple of mm closer to the front of the eyes thus enhancing the optics. As you know from personal experience, the slightest movement of the glasses away from one's eyes translates into a loss of visual acuity.

I also think these lenses look a bit better because they don't produce the reflections that plano-fronted lenses do.

In any event, glad you like your new glasses.

guest 26 Oct 2014, 17:07


You to cross the pond.....and all have a happyhour hello, maybe dinner.

I told you the vision would be great in the biconcave's !! I'm glad I was right !

Lenschat??? when


Ellen 26 Oct 2014, 15:39

Guest. What exactly are you waiting for?

Paul. Larger frames are seemingly more fashionable these days and really there wasn't much choice, most of the frames were on the large side. I liked the ones I chose immediately when I saw them on the screen but they do look a lot different with my lenses in because of how they minimise my face. I still like them though and my peripheral vision seems a little better with them.

Paul 26 Oct 2014, 07:13

Ellen, yes, the larger frame size is the reason for the biconcave lenses. Keeps them (a little) thinner. What made you decide to get a larger frame?

guest 26 Oct 2014, 05:00

You are sooo right !

Glad you feel that way :)

When are you crossing the pond ?


guest 26 Oct 2014, 05:00

You are sooo right !

Glad you feel that way :)

When are you crossing the pond ?


hoffide 25 Oct 2014, 21:28

@DUDE, look here:

Likelenses 25 Oct 2014, 17:37


Yes you do look sexy.

Bioconcave lenses are as exciting as myodiscs.

Ellen 25 Oct 2014, 16:38

Yes I think it's the frame, much larger than my old ones, I love them, dare I say it I almost feel sexy in them. The concave fronts were probably necessary to get my prescription into the larger frame. The place I buy my glasses from has a camera to take pictures of people such as myself who can't see themselves wearing non-prescription specs. The problem is that a frame with no prescription in it had a completely different look with -20 lenses fitted. Anyone else have this problem?

guest 23 Oct 2014, 17:55

Hi Ellen !

My old g/f had -19, -20 and -4 astig. Remember, I think I mentioned this before. These were the ones she got when she failed her d/l vision test while in college. When she got these, she passed and thought the vision was better than her regular front thick back of the same rx!! So did the examiner, who failed her the month before-and she told her it was the same rx.

In the double digit minus numbers, today the cr39's biconcave work best. Back then they were glass ! She had them made in safety glass, verythick, but great vision !

What shape are they? Small?? Hers were medium - she joked they were so curved, you could drink from them lol !

She loved to joke at herself, before some idiot did !

All will be fine Ellen :)

High Myopic 23 Oct 2014, 15:31

Three of my pairs of glasses have biconcave lenses. One pair has -24 diopter lenses, the second has -29 diopter lenses and the third pair has -27 diopter lenses.

Ellen 23 Oct 2014, 13:53

I picked up some new specs today and to my surprise the lenses have concave fronts. I didn't ask for these so I'm wondering why the change. What dictates the need for concave fronts? My prescription is very nearly identical to a year ago so the only difference is I have chosen larger frames. I can't tell when I'm wearing them, they have fancy coatings, and my nearest and dearest say they suit me so it doesn't bother me. Just curious really.

HighMyopic 09 Oct 2014, 19:14

I got the prescription soft contacts from a very nice lady I met at the vineyard. She let me have a pair of her unused prescription contacts for me to try in my eyes. She said "try them and tell me what you think of them next time I see you." I absolutely loved her rx contacts in my eyes. The -5.75 contact in my left eye made my vision in that eye even better than my regular -5.50 lens of my glasses. The -5.75 contact in my right eye was a tiny bit blurry for my my -4.50 eye but still helped greatly. I hope to see this lady next week and ask her for a few more pairs of her contacts to wear myself. I want to ask her if she can get me some monthly soft contacts in her rx for my eyes to use.

Cactus Jack 09 Oct 2014, 10:21


Optical prisms have a lot of uses in world of science and optics such as changing the direction of laser beams or splitting white light into its various component colors. Prisms actually come in all sorts of solid shapes, but for vision correction purposes only triangular shaped prisms are useful.

If you look at a pure prism lens (no sphere or cylinder) it will have two long flat sides through which you look and a short flat side. In the ophthalmic world, this is called the Base of the prism lens. There will be a point opposite the Base, but often the point gets cut off when mounting a prism lens in the frame to give the lens strength enough to not break. The way a prism works is that light rays entering one of the long flat sides are bent toward the Base before they exit the other long flat side. The amount of the bend is a function of the Index of Refraction of the material of the prism and the angle between the two long sides where they meet at the point. The width of the base is a function of the angle at the point and the distance from the point to the Base. I urge you to look up Prisms for more detailed explanations of what happens to light as it enters and exits the prism

The primary application for prisms in vision correction is to correct horizontally misaligned eyes. Base Out (BO) prism is primarily used to correct double vision when the eyes are turned inward (crossed). Base Im (BI)) prism is used to correct double vision when the eye turn outward or diverge. Base Up (BU) and Base Down (BD) is used to correct vertical misalignment. Vertical and Horizontal prism can be combined in a lens to correct oblique misalignment.

This may take a bit of thinking to get your mind around, but PLUS lenses and MINUS lenses are actually made up of an infinite number of infinitely thin prisms arranged in a circle. In PLUS lenses, the base of the prisms is at the center of the lenses with the point out and in MINUS lenses, the Base is at the outer edge of the lens and the point is at the center.

You asked about Cut In and Cut Out. Base Out prism displaces the image seen through the lenses inward for the same reason that MINUS lenses do, though in MINUS lenses we call the effect minification. With Cut In, you can see the edge of the face against the background behind the individual. Base In lenses displace the images seen through the lenses outward, but it is extremely difficult to see as Cut Out. Cut Out is more noticeable in high PLUS lenses where the magnified edge of the face or area around the eye fills the lens.

Hope this helps.


Dude 09 Oct 2014, 08:45


I've a little doubt, if BO add 'cut in', what does BI add?

Also,can you add a photo of a BO and BI? Please

glassesforeveryone 09 Oct 2014, 01:55

To get more cut in you could add BO prism in each lens. That will add to the 'cut-in' effect.

gwgs 09 Oct 2014, 01:19

In order to get more cut in, HighMyopic, you will need to have a higher prescription - this goes without saying - as the higher the prescription, the higher the 'cut in' will be. Unless you are doing GOC I don't see how you can double your prescription and still be comfortable wearing glasses at work - i.e. you're -5.75 now, but want to "add another -6", this will make your rx -11.75. You will have a stunning pair of thick lenses, with lots of cut in and power rings, but how will you accommodate that huge increase? Time for GOC if you want to do this.

HighMyopic 08 Oct 2014, 12:22

I am wearing some -5.75 soft contacts right now. I will probably wear them this evening to the restaurant.

I really wearing love these -5.75 soft contacts.

Each eyes have a -5.75 contact in it.

I can see very well.

Likelenses 06 Oct 2014, 22:42


Well then maybe you should start.

Wine and cheese go well together,and cheese is known to help myopia progress.

HighMyopic 06 Oct 2014, 21:22

I do not drink any wine from the vineyard. I do the landscaping. I have no interest in drinking wine or any alcoholic drink.

Likelenses 06 Oct 2014, 20:28


Better quit drinking that wine from the vineyard.

HighMyopic 06 Oct 2014, 19:10

Can this RX be made into a myodisc lens with a special order?

Left eye, -5.50 diopters,

Right eye -4.50 diopters.

Or do I have to go up to at least -6 diopters? I have really badly wanted myodisc lenses for a long time with this pretty strong rx of mine. The second thing is my glasses do not have enough cut in. I want much more cut in in my lenses. Should I ask for normal non myodisc CR39 lenses next time that I get a increase and ask that the lenses be much much thicker for safety reasons? I work at a vineyard and am around heavy machinery, a forklift and 2 tractors some of the time.

Likelenses 05 Oct 2014, 22:39

I was not sure where to post this,but thought that here was best.

It is an interesting concept for minus lenses.

Patrick B 08 Sep 2014, 10:27

ric -- Try Optical 4 Less, which is a Hong Kong-based online optician, for your needs. They specialize in extremely strong prescriptions and at a very reasonable price. Since high-prescriptions can be tricky to do, I'd suggest you work with a local optician for your first pair of lenticular glasses so that you can get an accurate PD and an accurate measurement of your vertex distance before ordering another pair online.

Good luck and let us know how it goes.

ric 08 Sep 2014, 04:39

But are really expensive here.

ric 08 Sep 2014, 04:38

Im looking to change my glasses. Asked in the optician and told me about the lentilux kind, dont know the exact brand.

ric 08 Sep 2014, 04:38

Im looking to change my glasses. Asked in the optician and told me about the lentilux kind, dont know the exact brand.

Patrick B 07 Sep 2014, 08:33

Hi Ric: Yes, mine are blended lenticulars with negative carriers which I really like. First of all, the negative carriers I get are around -15 which means that there isn't that much of a cosmetic difference between the -23 prescription in the bowl itself and the surrounding carrier. The plus carriers create such a huge cosmetic difference between the bowl and the carrier and the plus portion of the carrier is always creating visual distractions especially if I don't look straight through the bowl itself. My lenses are also biconcave with about -4 in the front of the lenses.

Let us know what you decide to do.

ric 06 Sep 2014, 01:30

Hi Patrick, are these lense blended lenticular? i would like to get blended.

SC 04 Sep 2014, 02:58

John S,


Patrick B 03 Sep 2014, 09:50

Hi Adam --

Glad you're having a good experience with your first myodiscs. You paid a lot of money for them and might want to consider Optical4Less which is an on-line eyeglasses company based in Hong Kong. Their myodisc lenses are excellent and substantially cheaper. You can even get myodiscs crafted in 1.8 high-index glass. This is the place where I get mine.

Let us know how you get on with your new specs!

John S 03 Sep 2014, 09:05

Not odd at all. Your calculation should be fine.

+2.50 for distance, and a +3.5 add should work fine. I have done the same thing in a progressive. In your case, I would get a FT 35 or an executive bifocal.

Have the seg set high to make it easier to get into the reading lens. Remember to calculate the near and far PDs correctly. With a +6, it will make a noticeable difference.

SC 03 Sep 2014, 06:42

This will seeem like an odd question.

When I have spare time then I like to paint. I haven't had spare time for a few years but last week restarted a painting I hadn't visited for probably 4 years. I'd already started wearing glasses for reading but don't remember there being such an issue using them for painting.

Now I use glasses full-time but the reading segment was nowhere near enough for painting - it may have been in focus at 40cm but not at the close distance required. In the end I used a pair of readers over the top of my usual pair for the close stuff but pushed them down a bit so I still had the distance section.

My Rx is +1, add +2 so I was effectively doing +1, add +5 which was great for 20-25cm. Whilst I could order single vision glasses that were +6 they would be a problem in reaching for the paints and brushes. Can you order an add of +5, or do you go for a distance increase, say to +2.5 add +3.5 so at least you get vision out to 66cm, which is probably enough.

What do other people do, if anything?

GreginColo 02 Sep 2014, 05:42

Thanks Adam for sharing about your new myodisc lenses. I am glad they provide you with such clear vision and you like the look of them. Any pics you would be willing to share would be greatly appreciated. Thank again.

Adam 02 Sep 2014, 04:22

My prescription has hit -18 and with -3 cylinder I've just collected my first pair of myodisc lenses. With 1. 67 hi index lenses.

I had spent the two weeks being incredibly aprehensive but they are incredibly clear to see with.

The circles have blended edges so they look ok.

I'll try and get a couple of photos posted somewhere later.

The downside was the price; £69 frames from Specsavers and £340 for the lenses. They've given me a 50% voucher off another pair so I may order some spare next month.

motard 20 Aug 2014, 04:25

Found a local shop that make "budget" eyeglasses with CR39 lenses. Thinking I might go cr39 for next pair

Daffy 14 Aug 2014, 08:36

Here's a novel idea that I think most here would be very excited to hear...3D printed lenses! Yes it is in development.

Imagine...printing your own lens in any power you wish and cut to your frame shape...heck...even print your own frames.

Daffy 14 Aug 2014, 08:36

Here's a novel idea that I think most here would be very excited to hear...3D printed lenses! Yes it is in development.

Imagine...printing your own lens in any power you wish and cut to your frame shape...heck...even print your own frames.

Revolver 14 Jul 2014, 14:18

Aviator, thanks for telling me what I should have known but didn't! So much of the equipment was B & L in that era, and mine is tucked away in a closet as I just don't have room to display it and bring it out as needed, too it for granted. Checked the nomenclature plate and it clearly says American Optical Lensometer, CSA APP. No. 2927 and CAT.M603L. It's black crackle finish, and as mentioned extremely heavy. But it works, Specs4ever has seen it and seen it in operation. It's very simple and reliable, but it is more accurate as long as you take the time to calibrate it before use which is very easy. Have had it many, many years and was very old when I got it. Wish I had the capability, would post a picture.

aviator -00-  14 Jul 2014, 03:17

Revolver: Thanks again. I just found this explanation on Ebay where a VINTAGE BAUSCH & LOMB UH VERTOMETER MICROSCOPE is offered fro sale: Vertometer was the trade name of an instrument made by Bausch & Lomb (B&L) and later by Reichert. Lensometer was the trade name of the nearly similar instrument made by American Optical. Neither the Vertometer or the Lensometer is now being made. Lensmeter is a generic name that can be applied to any lens measuring instrument. 'A vertometer' is an ophthalmic bench instrument used to measure dioptric power of a lens. It differs from a lensmeter or lensometer which is a general dispensary tool for opticians to verify spectacle prescriptions at the laboratory. A vertometer, on the other hand, is a more precision instrument used to locate, mark, and index a lens optical center for edging, mounting, and construction of a spectacle prescription

Revolver 13 Jul 2014, 20:02

Apparently, the portable is nothing more than a light weight version of the usual, it appears that it is in a case which is used as a stand and then after use the vertometer can be folded and stored in it for easy carry. It should do the same job as far as rx neutralization in concerned, but it doesn't seem to have the marking device to do PD's. Could be mistaken, never seen one before.

Also, apparently, the focimeter is another name for the vertometer so as to not use the B&L name of Lensometer. It should do the same job, perhaps vocimeter is the preferred generic name outside the US. Again, this is the first I've heard of it. Noted that they also advertise automatic models as well as the more familiar manual.

aviator -00-  13 Jul 2014, 13:07

Revolver. Thanks again for your advice. The details of the portable device I had in mind are on this site. How accurate do you think it will be?

Product code: 236400

Out of interest, does a Focimeter do the same job?

Revolver 12 Jul 2014, 14:11

Not sure what you mean by a "portable vertomer", they usually sit on a base and now most of those are made by non-USA manufacturers although some are sold by US companies. Many are now, and have been for some time, automatic which need little to no skill or training but I never found them to be as accurate as a regular vertometer and especially with prism. My personal one is an original B & L Lensometer, probably circa 1930's and if I ever decide to part with it should go to a museum....or to Cunard lines for use as an anchor on one of their ocean liners. It's that heavy, and you use an ink-tipped PD marker using the same principle described below.

aviator -00-  11 Jul 2014, 18:43

Revolver: thank you very much for this information on PD measuring. I am about to order a portable vertometer on-line, so that I can establish the exact RX of some glasses in my collection which were acquired 2nd hand with the lenses already fitted. Will it be obvious how to use the vertometer, or perhaps it will come with instructions. The other occasional use for the machine will be measuring the RX of the glasses of certain friends and house guests!

Revolver 11 Jul 2014, 14:24

Yes, they can measure P.D., that's actually the easiest part of verification. And without one, there is a relatively easy way to verify P.D. Take the glasses one eye at a time, line them up against a straight edge such as the corner of a wall or even your computer screen, move them until the focal lenghth is comfortable (this will vary from plus to minus etc.)and when the edge is perfectly centered in the lens dot it with a fine point water soluble felt tip pen. You may have to rotate the lens if there's cyl present to get the straight line. Do the same with the other lens, then measure the distance between the dots with your P.D. stick. This is every bit as accurate as a vertometer after a little practice. And BTW, the proper name for the instrument is a vertometer, lensometer is a copyrighted name used by Bausch and Lomb when the marketed the first ones.

aviator -00-  11 Jul 2014, 07:25

Can anyone tell me whether a Lensmeter can measure the PD of a pair of glasses of only the RX of the lenses. thanks

specs4ever 03 Jul 2014, 19:56

quite a few years ago I was able to get a pair that were -9R and -6L and they made them with a -0.50 front base for me. But they didn't want to do it and said that was too low a script for biconcave lenses

RL 03 Jul 2014, 18:46

High Myopic

I got my first biconcave lenses at minus 11. But I think you can get them as low as minus 6. I have a minus 2 curve on the front and they give great vision except at the very edge where there is more distortion than with a plano front. I currently wear -12.25 in both biconcave and plano lenses. I think three pairs are biconcave and four pairs are plano. The biconcave has better vision right at the middle of the lens.

HighMyopic 28 Jun 2014, 20:37

Can biconcave lenses be made in rx's as low as -6 or -7 diopters? I want to ask my eye doctor if I can get biconcave lenses for my next rx increase. I would really love that.

Likelenses 26 Jun 2014, 00:32


You have posted here,and on Lenschat numerous times. There is no need for the multiple posts,and requests.

You are becoming a nuisance,and I suspect that you are the same person that has been a nuisance under other screen names.

Shape up,or go away!

HighMyopic 24 Jun 2014, 23:25

If anyone has any strong glasses they cannot use and want to donate let me know.

Contact me at and we can talk.

I do not want any glasses with prisms in them. I would absolutely love to have all of your strong non prism glasses that you do not need anymore. I collect them and love wearing very strong glasses.

HighMyopic 24 Jun 2014, 17:41

Patrick B, you have any pairs that you cannot use any more? I would be happy to wear them for you if you cannot use them.

Patrick B 24 Jun 2014, 15:41

High Myopic:

Myodiscs and lenticular lenses are one and the same. In the U.S. the term myodisc is used; in Europe it is lenticular.

I agree with Andrew that blended myodiscs (lenticulars) are superior aesthetically. Mine are a bit less strong than Andrew's but I do the same thing and keep a pair of "readers" with a lower prescription that is a conventional myodisc design. My distance vision isn't 20/20 but close enough for me to drive, especially during the day.

HighMyopic 24 Jun 2014, 11:24

You have any extra pairs that you do not need anymore? If you do I would be very happy to wear them if you can not. I love very thick and strong glasses and love to wear them.

Andrew 24 Jun 2014, 11:14

I wear blended myodiscs with -28 for distance and a pair of non-blended myodiscs with -24 for reading.

In terms of vision, I do not notice the difference. However, from an aesthetic perspective, I'd recommended the blended every time.

HighMyopic 23 Jun 2014, 22:23

Is vision with lentictular myodiscs good? Do they affect how things look? Are things look rounded and fisheyed in them?

Or is vision with regular myodiscs better? I have always wanted to try on a pair of lentictular myodiscs before.

GreginColo 23 Jun 2014, 08:21

Thanks JP for your detailed reply to HiMy. To answer your question, I also prefer the look of the polished edges, especially when the frames are more delicate or revealing. With heavier plastic frames , it doesn't matter quite so much as less of the lense profile is revealed.

HighMyopic 21 Jun 2014, 13:36

I really wish my glasses had 2 inch thick lenses. I would love that.

JP 21 Jun 2014, 07:31

HighMyopic - Traditionally those who make glasses have simply cut the lens to size/shape from the blank, giving the "frosted" edge that you see in the second frame.

In recent years many dispensers have put in some extra work to polish the edges for that attractive crystal-like edge because they feel it's better cosmetically. I, like you, agree with them - all those lovely reflections in these jewel-like lenses. Equally, when the frame style and matte edge suggest a guy's worn his glasses for years, I think of how dependent he is upon them (even if he barely thinks about it) and how he's worn his glasses so close for years, letting them become part of him.

I've noticed that few dispensers state whether or not they'll polish the edges, so you don't really know until you receive your glasses. It's as though they've launched a new feature but haven't asked the customer or taken the opportunity to make a little more money on the feature.

I'd be interested to know whether people prefer polished edges?

HighMyopic 21 Jun 2014, 01:49

Why are some very thick glasses lenses very translucent looking like this?

And some are much more opaque like this?

I absolutely love the look of the translucent thick lenses.

Mr Cockeyed 09 Jun 2014, 14:11


yes, fused glass bifocals are crown glass for the upper section, the bifocal segment is flint glass

Astra 08 Jun 2014, 10:41

Is it possible to use two different material on one spectacle lens ?

Jim 06 May 2014, 00:56

Has anyone tried the "Emergensee" adjustable glasses by Adlens?

I am wondering how good the acuity is with them.

Is it good enough to read?

Can you identify street sings at normal distances if you are nearsighted?

guest 13 Apr 2014, 17:28

Several months ago-some information was posted-from a scholarly source - stating that the eyeware retailers are misleading the customers with hi minus rx's. All over -4 are told to get high index to increase the cost. However, once over -8 its well known that the old cr39's give the best corrected vision. (unless expensive thin glass from Europe) Where is the back up on this????


Galileo 22 Mar 2014, 08:37

Owlish - thanks for this. I often wondered about mixing lens materials for cosmetic effect where the patient has very different Rx in each eye. It is interesting to see it in practice.

Owlish 22 Mar 2014, 07:11

To TheBrit; something that may be worth looking into: at the following webpage,

if you scroll down to the bottom you will see diagrams of "lenticularized prism" lenses which seem to be "cut like a myodisc to save some weight & edge thickness" and available from this supplier.

Andy 22 Mar 2014, 06:59


I would second you comments entirely

I am currently prescribed 24BO and 10BU, my true correction is 40BO and 14BU which my ECP refuses to give me.

This is for a good reason and relates to previous points. ECP's like to correct you to a pint where you are able to fuse images but this can be a long way from you true correction.

Secondly this gives the ECP and the patient a degree of reserve prism which can be prescribed if an increase continues.

back to Stingrays point this is why it is not uncommon to see many increases.

As there are eight muscles in the eyes the correction can be complex, ie vertical and horizontal imbalance and rotation of the eye.

I am also informed vertical prism is much more susceptible to rapid increase so ECP's will avoid this wherever they can.

CG 21 Mar 2014, 18:07

thanx all. it was absolutely right and what I fought of

Interesting history

Cactus Jack 21 Mar 2014, 13:56


My experience with prism has been similar to yours. The need for prism correction is caused by a completely different set of eye muscle and eye positioning control system problems than any refractive error. There can be some inter relationship issues between Hyperopia and the need for BO prism because of the inter connection between the focus control system and the convergence response in the brain.

However, I think one of the reasons for prism increases is that most ECPs are very reluctant to fully correct horizontal prism. I was told by an ECP on one occasion that he had been taught to prescribe 1/2 the measured prism correction.


TheBrit 21 Mar 2014, 11:32

I have seen many postings recently about prism glasses, some positive, some critical, but it should be understood that glasses with prism correction is the only way for some people to have good vision, & comfortable vision. The question was raised why people continue to have numerous increases in prism dioptre? Simple answer they need it just as normal glasses wearers need increases from time to time.

I myself started with 3 BO prism a couple of years ago & now at 10 BO in both eyes. My base prescription is around +3 with an add od 3. Not strong, but with prism added the lenses are 12mm thick on the outside edges. If it was possible to have them cut like a myodisc to save some weight & edge thickness I probably would. But its not.

No doubt in time to come they will increase further, but for the advantages they give I am very happy with them as I can go about my normal everyday life without ANY problems.

For me, Prisms are ideal & nothing to worry about using!!

Cactus Jack 20 Mar 2014, 15:58

New Glasses,

That is probably pretty close. Unless you have a wide face, I would probably order glasses with a distance PD of 67 mm If you are ordering bifocals or progressives I would use 64 mm as the near PD.

How does this measurement compare with your averaged results.


New Glasses 20 Mar 2014, 13:12

@ Cactus Jack

I have tried your method, and also another one that consisted in wearing a pair of glasses, standing a couple of metres in front of a mirror and marking the centre of the pupil of each eye with a marker directly on the lens. I then measured the distance between the two marks and got 6.8-7 cm. I will try again and average the results.

Brian 19 Mar 2014, 14:04

For the Larissa story, look under Acuity and Prescription 1 and 2...

Soundmanpt 19 Mar 2014, 12:07


I am not sure if that is indeed the same person or not. This Larissa after starting off with a a weak rx of only -.75 -.25 in both eyes, only a few months later was being increased and also being introduced to prisms for the her next glasses. She had a friend come over and as they were sitting watching movies the friend spotted Larissa's first glasses sitting on the coffee table and put them on. The friend seems to enjoy wearing Larissa's old glasses and wears them on several nights out. Down the road a bit the 2 girls go on holiday and Larissa has had several increases in her glasses by this time. Larissa has a pair of her older rx sunglasses that has the prism correction in them. Her fried has forgot to bring her own sunglasses so she wears Larissa's instead. During their time away Larissa's friend can't decide if she likes the weaker first glasses that is just for distance or the stronger glasses that includes prism correction. Finally she decides to go full time with the prism glasses for the rest of the week. By the time they are returning home Larissa's friend has ruined what was before that perfect vision. Once back home Larissa's friend gets her eyes examined and is prescribed glasses nearly the same as Larissa's prescription.

I found several posts in the "Vision" thread starting back Feb 17 2003. but only a few and not the entire story that is still somewhere else.

I, Glasses 19 Mar 2014, 11:14

My actual Rx is -3. I'd like the lenses to be the thickness of a -6 Rx. Without resorting to GOC, what's the best way to achieve that goal via the mechanics and physics of lens creation?

CG 19 Mar 2014, 09:17


Wow you had posted while I was writing my lines haha strange coincidence. Is it in the same tread ?

CG 19 Mar 2014, 09:15

Thanks for the link Tessa

It wasnt the person I fought it was.

There was a girl here a long time back who got a pair of glasses from a poster here they were friends (can´t remeber who it was) she didnt need glasses but wanted to wear glasses. Or the glasses owner was a frequent poster and the friend posted after getting the glasses

later on she got a own rx but I dont remember if it was cylinder or prism involved or maybe both

Anyone remember who I´m thinking off ? I have searched from time to time in the archive but havent found the postings

Soundmanpt 19 Mar 2014, 09:11

CG and Tessa

There is still far more with the saga of Larissa. Things about how her bf broke up with her in part because she had gone to full time wear, and her mother also being unhappy with her for ruining her eyes. Even her best friend that had perfect vision also ruined her good vision by wearing old pairs of Larissa's glasses.

I came across the continuation about a year ago when I was back searching something else, but I also don't recall what thread it was in. I did re read it because it was so interesting and now I wish I had noted where it was for future reads.

Cactus Jack 18 Mar 2014, 18:18

New Glasses,

With a prescription near -5.00 it will not be easy to measure your PD because you will need to be close to the mirror to see the mm scale and measure accurately, but I think we can get close enough. Ideally, you should ask someone to assist you. The measurements are made without your glasses.

You will need a bathroom mirror and a ruler marked in mm.

1. Look in the mirror while holding the ruler so the mm markings are reasonably clear.

2. look at your left ear and measure the distance from the center of your nose to the center of your left pupil. Note; Your right eye will probably be turned inward but don't worry about that. If you can't see the mm marks, you may be able to mark the center of your pupil with the edge of your thumb and read the number by noting where your thumb is on the ruler.

3. Do Step 2 three times and average the distance.

4. Repeat Step 2 while looking at your right ear with your right eye.

5. Repeat Step 3.

6. Add the two resulting measurements and that will be your approximate PD. If you did the test yourself, I would suggest subtracting 2 mm because your eyes had to look slightly outward because you were so close to the mirror.

You might try repeating the test while wearing your glasses so you can be farther away from the mirror and compare the results.

If you are ordering bifocals or progressives, subtract 3 mm from the distance PD obtained above for your near PD.

You did not provide your complete prescription and if you have any prism correction, what you measure with your glasses will be off.

please let me know your results.


New Glasses 18 Mar 2014, 17:36

thanks to C for the detailed report on lens thickness. The one thing I have to check now in interpupillary distance because I am ordering online and my ophtalmologist didn't take this measurement. I'm a bit stuck. I can only vaguely remember in a former pair of glasses I had 62, but cannot be too sure, especially now I'm buying a new pair.

Tessa 18 Mar 2014, 15:15


Here it is.

The first post is dated 17 Dec 2001


Stingray 18 Mar 2014, 13:09

From what I understand about prism correction, please correct me if I am wrong, but isn't it caused by a muscle imbalance? If that is the case, with reference to the above you tube video, why would the guy in this video need constant and frequent changes in his prism correction? It would seem to me once the imbalance is corrected with the use of the prism lenses, then the progression would stop. But then again, if prism correction is the same as myopia where it increases over time, then I am incorrect. In the you tube video it just seems to me that his progression is non-stop and the prism lenses are not doing a thing for him on a permanent basis.

Stingray 18 Mar 2014, 12:41

Here is a Youtube video of still pictures of a guys progression from weak to super strong prism glasses.

Daffy 18 Mar 2014, 09:50

Is someone able to explain what going on here with the prism lenses? They seem to be extreme BD.

Ps it is a child but the mother is wearing them too. No explanation though. Intrigued.

CG 17 Mar 2014, 18:53

Tessa !

Or someone else

I have searched before after the postings from Larissa glad you put it on again.

But in what tread was it ? where do I find it ??


Melyssa 17 Mar 2014, 07:59

Aubrac & Soundmanpt,

This is the link to V&S:

That said, on this snowy Monday morning, I had to wait about 45 seconds for the website to come up, and here is what I posted:

I was having dental work done the other day, and the dental assistant and I were discussing glasses. She liked my red drop-temples. (It's never a bad idea to wear red when visiting a dentist, for obvious reasons. LOL) She wears rimless glasses with progressive lenses. In a rather stunning development, she has used the same frame for about 10 years now, through several prescription changes. I never knew rimless frames could last that long, especially with a strong prescription. She always has had lots of astigmatism, so contacts are out for her too. In spite of the boring frames, she did her job quite well.

FYI, my V&S avatar is my newest frame, navy blue and clear cat's-eyes.

Aubrac 17 Mar 2014, 07:17


Sounds interesting about your dental assistant - could you post your comments onto ES.

By the way can anyone tell me how to get on to V&S please.

Soundmanpt 16 Mar 2014, 14:27


I saw your recent comment over in V&S about your dental assit. and her rimless glasses she has had for 10 years and only changed lenses as her prescription changed. You seemed surprised that the frame would last that long. Well if your talking total rimless the there is very little frame if you even want to call it such. You only have the temples that are attached with drill mounting. and the bridge which is also drill mounted. Being metal the life time should be quite long. One interesting thing about that style is you can simply change the look of your glasses by getting a different shape of lenses. If you ever look at Zenni and click on a rimless style they have numerous sizes and shapes of lens options to pick from. Actually the most common thing to break with that style is the lenses where the drill mounts are. This happens mainly if the prescription is a very weak one and the lenses are just too thin and break near the holes. But it sounds like your dental assit has a decent prescription so her lenses are thick enough to not break.

I didn't reply because I somehow locked myself out of V&S and there doesn't seem to be going on in there anyway.

Specs4ever 16 Mar 2014, 11:00

Hi Nikko: I doubt that the ovecorrection you wore would have done anything to cause the glaucoma. Glaucoma is generally caused by the exfoliation of the inside of the eye(shedding of dead skin). This tends to block the drainage tubes from the eye and creates the pressure build up. But there are also other causes.

Niko 16 Mar 2014, 05:14


I'm nearsighted and astigmatism, I have a correction -2.75 (-1.00 to 90 °).

I wear all the time and for years a significant overcorrection in order to be more myopic. Currently -6.75 (+1.00 at 0 ° and -7.00 (+1.00 to 0 °).

In 2008 my new ophthalmologist to suspect an open angle glaucoma, and since I have to have regular exams and put drops in the eye every day.

I want to know if that little be due to overcorrection I wear for almost 10 years.

Cactus Jack 15 Mar 2014, 07:15


Your assumptions about prism are approximately correct. Prism bends light rays toward the Base of the prism. This has the visual effect of shifting the image away from the Base. Pure prism with optically flat surfaces does not have an optical center and typically does not introduce distortion provided the light rays strike and exit the surfaces of the prism at 90 degrees (perpendicular to the surface). The same is true with lenses, but the key factor is 90 degrees. If the light rays enter or exit the prism or lens at any angle other than 90 degrees, it will introduce distortion and the more prism or the stronger the lens, the more distortion you get when the light exits the prism or lens.

When considering how the light rays are affected by prism, think about the angles involved and the fact that a ray of light passing through the prism or lens and entering the eye experiences the same bending effects as if the light ray was originating in the eye and passing through the lens or prism. If a light ray enters the lens or prism at an angle away from 90 degrees, it will exit the lens or prism at an angle away from 90 degrees.

I would urge you to research the optical physics and mathematics of how lenses and prisms work. One thing to remember about prisms. In the scientific world, prisms are specified by the number of angular degrees it will bend a ray of light. In the ophthalmic world, prism is specified in Prism Diopters as originally defined by Sir Isaac Newton about 300 years ago. He defined 1 (one) Prism Diopter as that amount of prism that will bend or displace a ray of light 1 cm at a distance of 1 meter. If you apply the arctangent trigonometric function to that definition you will get 1 Prism Diopter bends light 0.57 angular degrees.

Prisms and Lenses can also have Chromatic Distortion as the prism bends different colors of light by different amounts. The general effect you get with strong opthalmic lenses is color fringing around light sources. Another interesting effect of Chromatic Distortion you can get when you wear prism in your glasses is with LED based signs. Typically if an LED sign is producing amber colored light, it is actually being created by a green LED source and a red LED source in the same housing. LEDs produce mono-chromatic light of exactly the same wavelength. Without prism, you will see an amber light. With prism you may see a green light and an red light slightly separated. The amount of separation depends on the amount of prism.

You asked about how much prism is "safe". Probably any value of 10 prism diopters in each eye or less is "safe" meaning that when you take the glasses off you can fuse the images after a short time. However, you need to be aware that if your eyes have a natural tendency to converge or diverge, you may find wearing prism correction to be rather comfortable and that you prefer it in your glasses. Inducing the need for prism, particularly Base Out prism is very easy to do. Much easier than inducing myopia because your eyes naturally converge when you read. You can wind up cross eyed.


Tessa 14 Mar 2014, 10:56

Thank you for the answers.

Cactus Jack

If I am looking through my current glasses for a lamppost in the front of me it is stright, but when I turn my head right the top and the bottom seems to be curved to my nose. Also the whole lamppost is shifted to the right side. If I am right it is becouse infinite number of prisms are arranged in different angles. So lenses with BO prism only are going to shift the lamppost nearer to the center without "barrel distortion" effect. Is it right?

I am guesing it propabbly depends from person but what average prism strenght is "save" to wear without risk of becoming dependant?

Curious as Well

I am not sure yet whether I wont to induce real need for prism. I would like to realy need glasses since I woke up in the morning. What I like in BO prisms are thick edges. I think about 6 mm thick edges is what I want.

I am 37 years old so it is to late to induce myopia. I had "wet eye exam" two years ago hoping the doctor will find some latenant hyperopia but my worse wye is only +0.5 with -0.5 astigmatism so there is no chance to really ned glasses for  longsightedness and for full time wear.

I really don't know why I want it. It is probably like smoking. You know it is unhealthy but you are starting to smoke. What I know I wouldn't mind to wear glasses non stop so I do not think it is a real damage to the eyes.

As I am suspect person who wears prisms can still drive a car, wear sunglasses and do all the activities  myopic or hyperopic person can do? Is it correct?

And one  more question. As I saw in old Larrisa's posts her friend become depended of BI prism and also had some minus cylinder. Is it becouse the angle of an eye has changed? Is it going to be the same with BO prism? Will my eyes become shortsighted becouse of prism?


Cactus Jack 14 Mar 2014, 04:38

The post below was from me.


 14 Mar 2014, 04:37

New Glasses,

Check out this lens thickness calculator:

I used it for a trial calculation and came up with a 0.1 mm difference in edge thickness. 1.67=3.5 mm and 1.74=3.4 mm. In both cases it used a center thickness of 1.5 mm. Center thickness can be a very big factor in edge thickness.

In some countries, glasses lenses must pass a minimum strength test before they can be delivered to the patient. That test may affect center thickness which directly changes the edge thickness. In the above example, if the center thickness had to be 3 mm to pass the test, the edge thickness would be increased by 1.5 mm for both 1.67 and 1.74.

I did the calculation again using Hard Resin (CR-39 perhaps with a IR of about 1.49) as the lens material and it came up with 2 mm center thickness and 4.9 mm edge thickness.


new glasses 13 Mar 2014, 13:20

@ Likelenses

I'm a guy and would like the thinnest possible, but if the thickness is roughly the same, I'm going for the cheaper!

Cactus Jack 12 Mar 2014, 18:55


What you are experiencing with the -10 lenses is called "barrel distortion" or spherical aberration. It is common in higher minus lenses. The "sweet spot" for almost all high prescription lenses is right around the optical center of the lens.

Prism lenses have their own set of factors that introduce distortion primarily caused by the angle that your central axis of vision impinges on the lens. The ideal angle is 90 degrees or straight on, but the typical mounting of BO prism lenses in a glasses frame is with the thick part behind the frame. This increases the angle. Ideally a BO prism lens should be mounted with most of the thick edge in front of the frame, but that would be unattractive.

Part os what you are experiencing with the -10 glasses is prism related because minus lenses are actually an infinite number of very thin prisms arranged in a circle with apex of the prism at the optical center of the lens and the base of the prism on the outside of the lens. When you look to the side, the angle of incidence of your central axis of vision is way off the 90 degree ideal.

Can you become dependent on wearing BO prism? Yes, particularly if your eyes have a tendency to turn inward anyway. It is much easier to "Induce Prism" than it is to "Induce Myopia". That is one of the reasons that some ECPs are very reluctant to prescribe full prism correction, unless there is no other choice.


Curious as Well 12 Mar 2014, 12:20


To help answer your question about the "bending effect" knowing what you actual prescription is if you have one. If you have perfect vision your glasses may be a little too strong to go with your contacts in that case. You are correct in thinking that it is always better to over correct than to under correct.

I don't think wearing glasses with 10 BO prism for a day would cause your eyes to become dependent that quickly, but really why even take the chance? Clearly you either have perfect vision or near perfect vision why do anything that could permanently damage your eyes. Doing GOC will not do any harm to your eyes. Or even "inducing myopia" you can at least dictate how far you want to go with that. And still have the option of wearing contacts if you tire of wearing glasses. But as you must know contacts are not an option for prisms.

Tessa 12 Mar 2014, 04:57

Hi. I am curious, when I wear -10D glasses (with +8D contacts) and I look left or right everything is bent. However everything looks ok when looking straight. Is it going to be the same effect when using plano glasses with BO prism? How strong prism per eye should be to have the same effect?

What is the borderline of not being permanently dependent of base out prism? Ie. doess wearing 10D BO prism per eye for a day may cose dependancy ?


Likelenses 11 Mar 2014, 17:37

new glasses

It would not be much difference between the two.

Now if you want a thicker look,then get CR-39 plastic lenses.

Are you a guy,or a girl? Girls look so great in thicker lenses.

new glasses 11 Mar 2014, 16:59

My prescription is around minus 5 and I am not sure whether ordering much more expensive 1.74 index lenses as opposed to 1.67 lens would really make a big difference in thickness. The glasses are rimless, the lens size around 5 cm / 2 in across. What do you reckon?

Cactus Jack 01 Feb 2014, 17:24


Ideally, it would be desirable to mount prism lenses where the thick edge extends to the front of the frame, and the back surface of the lens would be flush with the frame, but they would not be very attractive. Considerable effort is made to mask the edge thickness of prism glasses by using thick frames or massive temples and a lens that extends in front of the frame would probably be unacceptable.

A few years ago, some antique high prism glasses were advertised on eBay (I think). The lenses were mounted in the gold metal frames so that the back surface was flush with the frame and the lens extended in front of the frames. They were not particularly attractive, but I suspect they had better optical characteristics than prism lenses mounted with the front surface flush with the frames and the mass of the lens behind the frame.


Danbert 01 Feb 2014, 13:54

Cactus Jack,

Yes I ought to draw some diagrams...

I am interested in your last comment regarding the central axis of vision not impinging at an ideal angle due to the way prism lenses are mounted. Is there anything that can be done about this or is this just an issue with most frames?

Cactus Jack 30 Jan 2014, 22:59


BO prism significantly affects Cut-In, even to the extent where low plus lenses will exhibit Cut-In and minus lenses will exhibit much more Cut-In. Cut-in is actually visual displacement of the area around the eye as viewed from the front of the lens. Cut-in and Cut-out can exist in all lenses, but are not generally as obvious in plus lenses or BI, BU or BD lenses because displacement of the flesh in those areas or directions are hard to detect, particularly if the flesh has no blemishes.

The reason for this displacement, is that both plus and minus lenses are made up of an infinite number of infinitely thin prisms arranged in a circle. The difference between the two lens types is the location of the apex or sharp point of the prism. Plus lenses have the apex at the outside of the lens and minus lenses have the apex at the center of the lens. The prisms bend the incoming light rays toward the base of the prisms and the bending of the light rays occurs in both directions of light transmission thru the lens.

If prism is required to correct strabismus, the base of the prisms will be thicker in the direction specified, BO and BI in the horizontal direction, BU and BD in the vertical direction. It is possible to have horizontal and vertical prism in the same lens to produce oblique angles of prism if needed.

There is no Optical Center associated with pure prism, however if the prism is part of a plus or minus lens, optimal optical performance will occur if the Optical Center (OC) of the plus or minus lens is coincident with the central axis of vision. If prism is necessary, the PD, which is the distance between the OCs of the two lenses needs to be adjusted using Prentice's Rule. The amount of displacement is approximately 0.25 to 0.33 mm per prism diopter. The actual amount can be calculated by using trigonometry and the definition of a prism diopter as that amount of prism that will displace a ray of light 1 cm at a distance of 1 meter (100 cm or 1000 mm).

When calculating the displacement of the OC and PD, you have to use the distance from the center of rotation of the orb of the eye to the point where the central axis of vision impinges on the back surface of the lens. Typically, it is 1/2 the diameter of the orb (about 12.5 mm) plus the distance from the front surface of the cornea to the point where the central axis of vision impinges on the glasses lens. It is usually a bit more than the Vertex Distance.

It is very useful to draw an to scale image of the relationship between the two eyes and glasses lenses as seem from above to help you visualize what occurs with strabismus and corrective lenses. To construct the drawing, it is easier to represent the displacement of the central axis of vision from straight ahead to its prism deflected location by using 0.57 degrees per prism diopter.

In most instances, the central axis of vision will impinge on the back surface of the lens at an angle rather than the ideal of 90 degrees because of how prism lenses are mounted in the frame. This will cause some optical distortion that is difficult to compensate and will likely cause some reduction in Visual Acuity.


Danbert 30 Jan 2014, 19:08

[Op, feel free to delete my last comment - I misread JP's post...]

JP, Sorry about the last comment which doesn't answer your question.

I believe that the answer is yes - measuring the PD of a turned eye is not as straightforward as an eye that is 'normalised' or straight.

If only one eye is turned and your face is roughly symmetrical, you could take a single or monocular PD of the non-turned eye and double that. But I'd want someone with some skill to measure my PD in that case, to be sure.

Danbert 30 Jan 2014, 19:00


Yes indeed. But some online retailers don't offer prism, so if you want to induce small amounts one could adjust the PD to suit.

Perhaps one could also casually get an optician to accept an official prescription from another optician without any prism but using a custom PD (assuming they don't manage to actually take a measurement) in order to unofficially induce some prism.

But of course given the option just specify the correct PD and correct prism correction...

svensont 30 Jan 2014, 15:51


Your thinking is correct, I have the same results.

7mm of decentration on -3D: 0.7*3 = 2.1D prism on both lenses (1.05D per lens). If you add the decentration to PD, then you induce BI, if you substract, you induce BO

JP 30 Jan 2014, 15:21

Thinking about prism and PD, if a person's eyes don't look directly ahead (i.e. parallel), this must affect their PD. So if I needed prism would the eye doctor use my actual PD (e.g. reduced by eye convergence) or measure the PD based on each eye unconverged.

I expect that reducing the PD due to convergence, and then using prism, could be some kind of dual accounting?

(Excuse the cross-posting. Not sure where to ask this.)

Danbert 30 Jan 2014, 15:00

Sorry to double post. I just want to check my logic.

Let's propose that I want to induce 1 prism diopter per eye by decentration only (adjusting the pupillary distance). With a concave lens, the optical centre needs to be moved outwards in order for BI to be achieved.

If Pupillary Distance PD = 63mm

Spherical Diopters (both eyes) = -3.00

Prism = Decentration * Spherical Diopters

Prism = Decentration * (-3.00D) = 1.05

Decentration = -3.00D / 1.05 = -3.5mm (per eye)

Decentration = 3.5mm => actual single PD ordered = 70mm

Can anyone see any issues with my working?

Danbert 30 Jan 2014, 14:07

Thanks Cactus Jack - a very lucid and clear explanation as usual.

Perhaps my friend's glasses have anti-reflective coatings or something...

So does prism correction produce a cut-in effect at all? I'm quite confused as to how both BI and BO could be the same in that regard, as seems to be implied here so far. Or are people simply referring to the increased thickness and power rings?

CactusJ Jack 30 Jan 2014, 13:08

Power rings are actually internal reflections of the edge of the lens. The thicker the edge, the more prominent the edge of the lens. Prism correction makes the edge of the lens thicker by about 1 mm per prism diopter in CR-39 glasses, but the actual amount depends on the the Index of Refraction and the distance from the Optical Center of the lens to the edge.

BTW, Scientific Prisms are denoted in degrees, but Opthalmic Prisms are denoted in Prism Diopters, often designated by a tiny triangle superscript after the number in a prescription. The tiny triangle is often mistaken for the tiny circle used to designate degrees. The difference between the units of measure is significant. 1 prism diopter = 0.57 degrees of angular deflection of a ray of light. Fortunately, opthalmic lens makers know that prism is designated in prism diopters not degrees or the resulting lens would provide significant under correction.


Brian 30 Jan 2014, 13:03

Danbert, Yes, the prism effect especially for Base Out will make the person wearing them look more myopic. With the Base In Prism that I have the inner edges of my lenses are much thicker than the outer edges of my lenses because the prism is based on the inside of the lense.

Danbert 30 Jan 2014, 12:43

The glasses in question don't have very noticeable power rings. The PD would be quite small and the overall width of the glasses is also quite small as the cut-in is quite well hidden face-on, but appears to be -3 or so from certain angles. It all makes me curious what the prescription might be. But for all I know it could just be simple myopia and I'm just getting tricked by the particular glasses in question!

I'm not sure right now if the thickness is on the inner or outer layers.

Regarding BI and BO, I would have thought that BI would have a cut-in effect, and BO would be somewhat the opposite? But Brian and Aubrac's comments both seem to suggest that both BI and BO make glasses look more myopic than they are?

Brian 30 Jan 2014, 09:07

The same is true for Base In as well, but just on the inner edge of the lense instead of the outer layer of the edge like it would with BO prism. My normal script is -6 and with 5 BI prism the inside of my lense looks like a -11 script and is very thick.

Aubrac 30 Jan 2014, 08:54


As Daffy said BO prism even at low level can add considerably to the lens thickness and appearance of power rings.

I got lenses with -4.50 both eyes and 3 degrees BO prism and from the side angle you would say they look more like -7. My wife has +2 glasses with 4 degrees BO prism and from some angles you would think she had about a -4 prescription.

I have not checked out the appearance of BI prism and can't comment on the effect this would have.

Daffy 29 Jan 2014, 07:53

It depends on the size of the frames/lenses and the PD. If the PD is small ie the eyes are close together and the glasses are large-ish especially narrow, the outer edge will look thicker on the outside. Of course if astigmatic on the vertical plane (90 degrees or there abouts) or prism BO will add to the said effect.

Danbert 29 Jan 2014, 05:50

Just a general question... I noticed that a friend of mine has glasses (minus / concave) but is noticeably thicker on the outside edges than on the inside (I'd say about double).

Could this imply a fair degree of astigmatism or could she possibly have some BI prism in her prescription?

Soundmanpt 18 Jan 2014, 13:03


So funny you mentioned Luxottica. In more recent years they have now slowly been buying out many of the designer names and making the frames themselves. One of the more recent names they now own is Ray Ban. But there are many others. Also they have bought out many of the bigger chain stores. They now own Lenscrafters, Pearles Vision, Sears Optical, Target Optical and Sunglass Hut and are close to closing a deal for J.C. Penny Optical as well. Now I heard they also own their own vision insurance company as well.

Doing these things has done nothing to lower the price of these designer frames or anything else. if anything it seems to empower them to charge even more.

There goal of course seems very clear to drive out all of the smaller stores until they are the only outlet. Trust me i am sure as i speak they are working very hard to shut down on line retailers as well. I have heard form sources they fear the on line retailers more than anything else because so far they don't have a way of stopping them and lets hope they don't. One of the things they have inacted is refusing to provide the necessary PD measurement needed to order glasses on line at all their outlets.

Daffy 18 Jan 2014, 09:21

As for's the biggest rort we face...I went along to a trade show / conference event last year and the year before...(yes I posed as an importer/distributor to get invited) and got to talk to many frame and lens manufacturers from many places. The basic Cr-39 lens cost $1.50 per pair...and that's if I buy a few. But if the qty increases price per pair drops obviously. Higher power incurred a measly 1 buck more for greater than -8 or +6. A 1.67 index lens was about 3-4 dollars. Multi focals were about 8 to 12 dollars per pair. Our real cost on multifocals is the labor cost of grinding the main Rx into the multifocals are blanks/planos with the add...the manufacturer cannot possibly make nor could the dispenser carry every possible combination of cylinder angles. So they are made and shipped as very thick blanks with the add and the front/back of the lens is ground down. It gets technical and far too lengthy to write more on this process.

I managed to purchase many pairs of lenses of differing powers from +15 to -24, including lenties and myodiscs...I wish I had a edge grinder to make my own glasses...but I'm working towards that. So I have two box full of lenses for about $100. I tried off loading the lenses but got too caught up on eBay as I never sold anything on it and hadn't had the time to sign up.

Daffy 18 Jan 2014, 09:02

If you look into the history of "designer" frames, you will read that these frames have been made/manufactured from the decades old frame manufacturers like "luxottica". It's just that in more recent times when glasses wearing became a statement rather than medical device that companies like "luxottica" acquired contracts to brand the frames as designer. This approach became a gold mine for these companies...and the public is falling for it.

I actually detest the term "designer" as I feel even the cheap 8 buck frames was "designed" by someone...only their "name" will never be known.

Clare 17 Jan 2014, 17:37

Melissa, Soundmanpt - I agree, very expensive, more than I'd expected that someone would have to wear for progressives (which I now know they are for certain). I understand that people may feel they need to spend a fair amount for glasses that look good - I paid around £300 for my Face a Face which I now wear regularly and I'm very happy with them so paying that seems like a good investment. I was horrified at the cost though as I guess I will need progressives in the future like most people. I like things that look good quality but don't feel the need to be showy with designer labels so completely get that options like Zenni are a good alternative.

Soundmanpt 17 Jan 2014, 12:01


Very simple, your paying for the name of the designer. And please I don't want to hear that they are better quality because plastic is plastic and just as Melyssa said she has her collection and never paid more than $100.00 for anyone pair. Her glasses have lasted plenty long.

Beisdes the high price I can think of 2 really good reasons why paying that for glasses is crazy. First of all for most there is a good chance your prescription will change and then you need to decide if you want to just replace the lenses and continue wearing a frame that is now becoming dated. So it doesn't matter how much you pay for them because styles will change. Maybe its just me I also have never really figured out the concept that it makes sense to pay a fortune for a designer anything so you can provide that designer free advertising. If anything they should pay you to wear their products. I love seeing people walk around with those T-shirts that have the big logo for Nike covering the whole front and you get to pay way more for the chance to advertise for them then if you simply got a normal T-shirt with nothing on the front.

Melyssa 17 Jan 2014, 08:19

I wish I were that wealthy. :) Replacement lenses for my frames run $40 a pair, and in my entire collection of glasses since first getting drop-temples 30 years ago, I have had just three pairs that cost over $100 complete.

Clare 16 Jan 2014, 16:04

Overheard someone at work saying they paid £800 for glasses. Gucci frames and look like progressives but £800, really?

Clare 16 Jan 2014, 16:04

Overheard someone at work saying they paid £800 for glasses. Gucci frames and look like progressives but £800, really?

Clare 08 Dec 2013, 16:24

Thanks Soundmanpt for the recommendation. I'll mention that at my next appointment.

Astra 06 Dec 2013, 01:03

Are there any stores still supply CR-39 for rx around -9 ?

A-20 15 Oct 2013, 14:43

@I, glasses,

I was curious about this as well. One of the problems with this is that after he died, his family gave away mementos of him, including his glasses. No surviving pair of his (confirmed) glasses have ever been tested. However, the navy surgeon responsible for his eyesight, Dr. E. J. Grow, saved a box with 2 lenses in it and a note that said "The lenses were worn by Theodore Roosevelt during his entire presidency. He always had several pair available, as he was 8 D myopic and could see but little without them." However, the doctor's widow had the lenses in the box tested by her ophthalmologist to be -7D. The box was eventually given to the TR Collection at Harvard. It has since been we might never know the scope of his myopia.

tl;dr: TR had glasses with lenses about -7D or -8D.

Melyssa 04 Oct 2013, 08:01

When I first started wearing glasses so many decades ago, lenses were glass, not plastic, and my parents always made sure that mine would be shatterproof. It was probably in the early 1970s when my lenses became plastic, and I have used the famous CR39s since. I can handle the thickness, but not the cost of having high-index lenses in 45 pairs of glasses.

 04 Oct 2013, 03:25

How would I go on getting contacts? When I got my vision checked and my glasses prescription, the optometrist asked me if I wear contacts and I simply said no. So she didn't give me a test for contacts. Can I go with my latest glasses into a glasses store and get tested for contacts? How much will it be also? My prescription is -2.75, -0.75, with a bit of astigmatism

I, Glasses 05 Sep 2013, 09:29

What was Theodore Roosevelt's eyeglasses pres ription?

NJ 03 Sep 2013, 19:00

The main reason I've heard for using polycarbonate is the superior impact resistance. Kids are often prescribed poly lenses because of this.

NJ 03 Sep 2013, 19:00

The main reason I've heard for using polycarbonate is the superior impact resistance. Kids are often prescribed poly lenses because of this.

Filthy McNasty 03 Sep 2013, 18:15

My guesses, as a total outsider, would be:

1. Poly offers thinner lenses without huge cost increment;

2. Many people don't care about chromatic aberration, at moderate powers, or care more about thinner lenses than optical quality, or fail to realize what chromatic aberration looks like in higher powers until they have placed the order;

3. Many opticians (don't know/ don't tell people) about abbe values; and,

4. Sellers push poly as a way to up the sale amount over simple CR39.

Neil 03 Sep 2013, 16:32

@John S

One question: If poly is so inferior, why does it remain so popular? It's even listed on my Rx (along with PAL) as a recommendation!

People might say that shops like to push people toward more expensive lenses, but there are newer materials like Trivex, and high-index lenses, all of which could be even more expensive. Presumably opticians and optometrists would not recommend something old and inferior, when there are newer and better things out there.

Soundmanpt 01 Sep 2013, 14:16


Hey Clare I talking with a doctor friend last night and of course discussed various optic topics. Something came up about contacts and anyway I mentioned about the problems you have been having with your contacts and how you can only them a very short time theses days because of your eyes drying out. He told me about a new type of contact that might work for you. "Total 1's" Dailies by Ciba Vision/ Alcon

Neil 28 Aug 2013, 23:02

@John S

Thanks so much for the correction, and for the advice.

John S 28 Aug 2013, 21:57


The higher the index, the poorer quality of the optics. The best quality is glass or CR-39. Poly is the worst, and the high index lenses are slightly better.

Use your search engine of choice to find "abbe value", you will find out all the info.

There are a ton of progressives out there. I have not found any that are just flat out bad. My favorite lenses were the AO Techica, and the Sola VIP XL, both now discontinued. Most likely because I liked them. I have Hoya Summit ECP lenses, and also AO Instinctive lenses. Both seem to work well.

I like my fitting height set high so looking straight out the intermediate channel has already cut in. That would probably not work as well for you being you have a minus distance rx, but I like it because it gives me a larger reading area. Since I like a +3.50 add, I need all the height I can get. The higher the add, the more compressed the lens is, and the more "swim effect" there is.

I have been wearing progressives for almost 30 years. I am perfectionist, but I also know the lens limitations. Early on I trained my brain to adapt to them, so the progressives feel very natural to me.

Be aware of the pantoscopic tilt needed in the frame for progressive lenses. Without a ~10 degree tilt, the reading area can be much smaller and more distorted. Apparently there are some opticians that do not know this. It really does make a big difference.

I have a friend that has about a -2.00 cylinder correction, with very little sphere. I got him a pair of progressives. He said he can't wear them. He cannot deal with the unwanted cylinder in his peripheral vision. He is very stubborn, so he won't wear them full time to try to get used to them. Most of his friends and family wear them. This is a person that would cut his nose, spite his face to prove a point. He would rather just keep switching glasses to see.

Neil 28 Aug 2013, 03:38

I am debating whether to change to a new pair of glasses. Here is my dilemma:

My regular pair from my old local optometrist are rimless digital progressive, but they developed some serious scratches, so I ordered a pair from Hong Kong. These are much thinner and lighter, but the progressive lens design leaves much to be desired. The refractive index is 1.61, and I find that I see distance a bit sharper with these than with my old regular pair (disregarding the scratches).

Last week I went to get my eyes examined by a new optometrist, and she was quite impressed by the thinness of the lenses. She explained some of the FDA restrictions for thin lenses, particularly in rimless frames.

I really would like to get better quality progressive lenses, as I am tired of having to move my head from side to side. I am just wondering if I can get thinner lenses than my old regular pair. If I get a full frame rather than rimless, are my options greater? Is it right that visual clarity is better with a higher refractive index?

Thanks for the advice. I can barely remember my prescription (it's late), but it's around -1.5, around -0.75 astigmatism, with a +2 add.

Cactus Jack 15 Aug 2013, 18:23


The power of your glasses is determined by the difference in the curvature of the back side of your glasses lenses and the front side. The front side is called the base curve. For example, when your prescription was -8, if the base curve was +2.00 or slightly convex, the back side of the lens would need a curve of -10.00 to make the total -8.00. To minimize edge thickness and minimize edge distortion and / or barrel distortion effects, the curvature of the back side of the lens needs to be as low as possible which means that the front side or base curve also needs to be as low as possible or flat or as nearly flat as possible. The snag with that is that the reflection from the front surface will look unusual.

The nature of the reflection from the front surface of the lens is such that the higher the convex (plus) curvature the smaller the apparent size of the reflected image. As the curvature approaches 0.00 the front surface reflection looks more and more like the reflections from fake glasses lenses like we occasionally see in movies or TV shows. If your prescription gets to the point where you need a concave (-) base curve, the reflection will really look unusual.

About the only thing you can do is consider a high quality anti-reflective (A/R) coating to minimize the intensity of the reflection.

Sometimes, A/R coatings can be a bit pricey. However, if you would like to try ordering some glasses from an online retailer like Zenni, we can help you. You might be surprised at the low prices and the quality.


Heather 15 Aug 2013, 16:04

I'm a little confused about my new glasses. My spheres went up but my base curves went down. My old prescription was -8 and the new one is -9, which doesn't seem that much different. But when I first put the glasses on and looked in the mirror, I noticed that the reflections seemed much bigger. I asked the optician, who measured the lenses with a gadget and told me the reason for the bigger reflections was that the base curves went down from 2 to .5. I said I liked the number 2 base curves better and was told that the computer automatically picks the best base curve for each prescription. The optician also said that if my prescription ever reaches -10 I will get plain O base curves. I didn't even want to ask what those are. Since I am young (19) I am still getting more nearsighted and -10 is the next number. Can someone please help me sort all of this out. Thanks.

Cactus Jack 27 Jul 2013, 07:46


It may be possible to grind Fresnel prisms into glasses, but I have have never heard of it. 15/15 or even 20/20 BO is possible in some prescriptions without resorting to Fresnels, but the typical high volume lab may not bother. Be sure (if you can) that both the dispensing optical and the lab work together to adjust the PD in the glasses for the fact that your central axis of vision will be displaced inward for distance vision and a bit more for close. It is the same reason that two PDs are indicated for bifocals.


Roy 27 Jul 2013, 04:52

Thanks for all your help again Cactus and to John for the Fresnel lens supplier.

I bought a some prisms to apply to my current glasses. 5 dioptres helped reduce the double vision but still left some at the left and right side peripheral areas. 10 dioptres (5 in each eye)fixed it, leaving no double vision. This means I really need a total of 30 dioptres (shared) because of the 10 + 10 dioptres already in my current glasses. The Fresnel prisms took some getting used to and there was some reduction in visual acuity but I was quite pleased with them. From basic tests I did I would say my VA went from a marginal 20/20 with my current glasses to 20/30 with the Fresnel prisms.

Is there an option of having a Fresnel prism ground into the lens (with other corrections as required) or is "stick-on" the only option for Fresnel prisms?

Cactus Jack 27 Jul 2013, 02:30


If not CR 39, a very close formulation. Really excellent abbe value, makes a difference and CR 39 has the best of all plastic lens materials.


iamhacked 27 Jul 2013, 00:44

I got new glasses and the lenses seemed to be 0.5 index. Last year I think I got high index for my astigmatism. My vision is much clearer and vibrant with my new glasses. Is the lens probably cr39?

Kevin 24 Jul 2013, 12:43

Thanks to Cactus Jack, Clare and Eye Tri for your advice about trying to keep lenses demisted. I will try them out. I'm afraid it's not just when I stop that they get foggy, Clare. A few times recently in this hot humid weather (in the UK) I've had to take off my glasses as my vision with my steamed up glasses was worse than without them.

John 24 Jul 2013, 06:33

Fresnel lenses from Harlow, Essex, UK

They go 1,2,3 up to 12, then 15, 20 etc.

£13 ish each.

EyeTri 24 Jul 2013, 03:48


This may sound dumb, but it's cheap and it works better than anything else I've ever tried on swim goggles. Mix distilled water and baby shampoo (50/50). Put a little on the lenses, gently rub it around, and give them a quick rinse with plain water. I haven't tried it on my glasses, but it works every time on my goggles.

Clare 23 Jul 2013, 21:03

Kevin - I've only noticed its a problem when you stop running - quite motivating then to keep going!

Cactus Jack 23 Jul 2013, 16:54


The spray for swim goggles might be useful if you spray it on and then wipe and polish the lenses with a soft cloth after spraying. Be sure and read the label to find out if the spray is incompatible with some plastics. Before the spray stuff, we used to spit on the swim goggle lenses, rub it around, rinse it off and put on the swim goggles.

Glasses wearers who snow ski have similar problems with goggles and glasses.


Cactus Jack 23 Jul 2013, 16:48


You can get significantly higher prism correction from some specialty labs. I have some glasses that are 23/23 BO (without any vertical component), but few on line retailers will make glasses with that much prism or complex prism. They are just too much hassle. I spoke with one optician about high prism glasses. He said that he got involved with fitting a high prism prescription several years ago and they had to remake the lenses 5 times before they got it right. It it seems to me that making and fitting high prism glasses is a lost art.

All the old glasses makers (Before common muscle surgery) who knew how to make and fit high prism glasses are retired or dead. The prism part, up to about 12 - 15 diopters in each eye, is not too hard to make. The problem is that visual acuity can get really bad for the patient while the glasses read as exactly right on the machines that read the glasses prescription. Often, that is caused by failure to adjust the PD for the fact that with BO prism, the eyes are actually turned inward for vision straight ahead.

The situation where you see double looking left and right can be caused by a mechanical problem rather than an optical problem, but you probably should not be having that problem with 10/10 BO unless you have restricted motility for some reason. An example of a mechanical problem would occur where a person needs considerable prism like the 23/23 BO above. For vision straight ahead with the glasses, each eye will be turned inward about 13 angular degrees. If you look to the left, the left eye as plenty of range of movement before it will "hit the stop". The right eye has already used up 13 degrees of movement just to look straight ahead so it has much less range of movement before it hits the "nose" stop. The eyes may be able to track together up to this point, but when the right eye "hits the stop" against the nose, it can't go any farther and the eyes cannot track together. It is similar, but obviously not the same as the situation experienced by people who wear very high plus or minus glasses. They have to keep their eyes very close to the optical center (OC) of their lenses to see clearly. They to learn to move their head rather than their eyes to look to the side.

You are right to avoid Fresnels for almost any adult purpose except as a low cost way to find out i you can tolerate prism. Fresnels, particularly press-on Fresnels, are famous for having significant distortion. They may be OK for very young children who cannot read, but the are almost useless for adults.

You might check out Eyeglass Factory Outlet in Florida to find out what they can make.


Roy 23 Jul 2013, 15:59

Does anyone know the maximum prism strength that can be put into lenses before having to use Fresnel prisms. I am currently wearing 10 base out in both eyes and 2 base down right/3 base up left, combined with myopic correction of about -3 left and -6 right. I am now getting some double vision to the left and right of my field of vision. Holding a 4 dioptre prism (bought from an optical supplier)with base set to "out", in front of one eye fixes the problem. This indicates that I need 12 base out in both eyes. Is this prescription available without going to Fresnel prisms and, if so, does anyone know an online supplier who can provide it please? I will be going for an eye test soon but all opticians seem to measure prism needs looking only straight ahead and this understates the prism needed substantially so I have to do a bit of DIY prescribing.


Kevin 18 May 2013, 09:01

I've started jogging recently and have had problems with my glasses steaming up when I work up a sweat, especially in damp weather. When I asked my glasses-wearing friends if they knew of any anti-mist lenses, they said 'get contact lenses'. I've never worn contacts and don't really want to. When I did a web search I found a few spray-on products but most seemed to be for swimming goggles. Do you guys know of a solution to the problem? I'm moderately short-sighted with some astigmatism.

minus5wholuvsgwgs 16 May 2013, 00:30

My high minus gf (minus16.25/minus15.00) dug out a 30 year old pair very 1970s frames big and brown but it was fascinating seeing how lens technology has progessed these were presumably a little weaker she said she could not see well through them flat fronts of course but at least half an inch thick with so many power rings compared with her current pair Must admit though she looked so sexy in them !!

Buck 11 May 2013, 13:04

"Digital" progressive have been recommended. Prices are all over the place. $450 - $1200. Are they worth it, any brand better in quality or cost-wise? Don't recall seeing discussed before. One shop I've visited has a camera so all measurements are done by photo. Sounds good.

Cactus Jack 08 May 2013, 06:33


You might attract enough attention that the other patrons might want to know where you got the fresnel reader, with or without the LED. Same thing with the smartphone app. One thing you can be sure of, you are not the only one with the problem, just the only one that admits it and does something about it.


Slit 08 May 2013, 03:09

Hi Cactus Jack,

Yes, I have noticed the ones with LED. It is a little less compact than just the frensel sheet alone.

however, using just a credit card size frensel lens can do a very good job without getting attention of people around (which will be caused by the light of LED).

regarding phone app, yes i think its present.

SC 07 May 2013, 05:32


I read an article recommending higher index lenses above +2.5.

My question is what constitutes +2.5? If you have a Rx +1.25 add +1.5, then I assume they have to start with +2.75 and grind down the upper part of the lens.

So would that meran that Hi-index, eg 1.6 would make any difference?

Cactus Jack 06 May 2013, 07:40


Some even have a very small built in white LED to really help in dim places. I have often thought that in addition to being very useful in dim restaurants, it would be very useful for reading a map at night.

These days, a smartphone with a GPS map is probably best of all for that. I wonder if there is an app that uses the smartphone camera and display as a reading aid. The smartphone camera may not be able to focus close enough to be really useful for that application.


Aubrac 06 May 2013, 04:48


Yes the small lens sounds as though it could be very useful as most restaurants seem to like low lighting levels - possibly to avoid seeing what you are eating!!

My wife often carries a magnifying glass about 4" diameter and plus 2.5 which she has no hesitation to use when reading menus but something smaller would be great, although with her bifocals she now has less need for it.

slit 05 May 2013, 05:52

Thanks a lot CJ!

I was wondering, do people carry those credit card size fresnel lenses to read tiny text in absence of a pair of reading glasses?

It will look quite sexy for a girl out with me on a date to pull them out at a restaurant to read the menu. (Personally I have experienced someone who always complain at restaurants that menu is too hard to read. But we never talked about glasses. Next time I am gonna keep that pocket size fresnel lens and pull it out at a dimly lit restaurant)

ehpc 04 May 2013, 14:08

Very thick minus lenses are very cool Nicole :) Pete

Cactus Jack 04 May 2013, 10:07


They are fairly common in the US. I got a full page sized one for a friend a few years ago at an office supply store (Office Depot, Staples, or Office Max), if I remember right. I think it was branded Bausch & Lomb Magna-Page or something like that. Seems like it was under US$10.00.

They work best when held about halfway between your eyes and whatever you are trying to read.


Slit 04 May 2013, 03:11

while travelling in china i got a map which came together with a thin magnifying lens called "fresnel lens".

have any of you seen this in US or Europe being used by people?

REd 02 May 2013, 19:12


Yes you are beautiful and smart plus very sweet. Plus you see well with the appropriate correction. xoxoxo to you

Nicole-15 02 May 2013, 16:07

Thanks everyone, and especially REd. So here’s the story on my new glasses.

My mom and I went back to my optician and then to my optometrist who squeezed me in for a follow up.

By the way, I asked my mom what the prescriptions of the rest of my family are. She said hers is -3.50 and my dad is -6.00 and my brother, who is 2 years older than me, is -6.00 and going up a lot slower than mine. So I somehow got the bad genes. Oh well, Im beautiful and smart so I did get some good genes lol.

My new frame is the same size as the old one but a slightly different shapeand color. The lenses are the same, too, high index plastic with a RI, like you explained REd, of 1.67. The optician said I could have gotten 1.74 but they’re a lot more $$$ and since I might need even thicker glasses in 6 months it’s not worth it.

The optician told me to run my finger through the inside of the old glasses and then to do the same to the new ones and asked if I could feel the difrence. Yes, it was obvious, the new ones felt much curvier. That’s what makes them stronger but it also makes them thicker because the back curves away from the front much quicker so by the edge it’s much further away.

Then we went to the optometrist. First she checked the new glasses in a special machine and said they were exactly what she had prescribed. She gave them back to me and asked me to read as far down as possible and I passed. Then I switched into the old glasses and I failed miserably. So she said, see, you really need all that extra minus.

Then she did an experiment. She held 2 loose lenses in front of my glasses and asked me if it made the letters better or worse. Definitely worse. Then she took them away and held up 2 different lenses. Definitely better, even better then the new glasses by themself.

So she said, my actual new prescription should have been -11.75 and -12.25 but she reduced it by .25 because it was better for me. The 1st loose lenses were +.25 and the 2nd ones were -.25, so I could see that I was undercorrected and not overcorrected.

So I asked her, does that mean my real perscription is actually even thicker than these glasses? She said yes, but just slightly. And I asked her, does that mean my next glasses will get even thicker? She said (I wanted to cry) “absolutely. You’re a very myopic young woman and your eyes aren’t going to improve. The best you can hope for is no change but given your age and history, my guess is your going to continue progressing.” I said what can I do to stop my eyes from getting worse and she said realistically, nothing.

I asked her how much worse my glasses might be next time. OMG she didn’t want to predict but finally she said hopefully less of an increase then this time. If my eyes stay the same, -.25 more and if they do change, maybe -.50 to -1.00. So…that’s the story of me and my eyes and glasses.

Thanks for explaining. xoxoxox

REd 02 May 2013, 11:20

To Nicole-15

You are exactly correct; the higher the sphere number the thicker the edges of minus lenses, if all other factors are constant.

While I completely agree with Melyssa’s posts to you, some elaboration may be helpful to you.

Visualize a flat piece of glass. If you add a piece of glass to it with a curved surface you can make a plus lens- not what you need for your myopia. Take that same piece of flat glass and carve from it a curved surface so the middle is thinner, you’ll have a minus lens which is what you need for your myopia or nearsightedness. So add material to get a plus lens, subtract for minus. I ask you to visualize this for illustration only; this is not how lenses are made. For a minus lens the thinnest portion is the optical center and it is typically 2 millimeters thick. When this lens is fitted into the frames you have chosen the optical center of the lens will be directly in front of the pupil of your eye. The further from the optical center, the thicker the lens (for minus lenses) will be. The thickest part of the lens will virtually always be at the outer edge.

If you are concerned about the edge thickness there are two main factors you can control- frames size and refractive index (RI) of the lens material.

The smaller the frame you chose the thinner the outer edge will be. Of course the smaller the frame the smaller your field of vision, so you’ll need to find the best compromise for you between edge thickness and field of vision.

Refractive index (RI) of the lens material is a measure of its ability to bend the light. The higher the RI, the thinner the edges. A common lens material is “Hard Resin” aka CR-39 with an RI ~1.49. Any lens material with an RI above 1.49 will give thinner edges if all other factors are equal. Perhaps your new glasses are made of lens material with RI 1.74 or higher. You may not know what it is however the supplier of your new glasses must be able to tell you. Higher RI lenses sell at a substantially higher price than CR-39 lenses.

Some people try to disguise edge thickness by frame design factors. Wide side arms make it difficult for others to see the edge thickness. Some women with long hair put some hair inside their frames and the rest outside. Both of these techniques will obscure your side vision, so, once again, you must determine the correct balance for you.

You stated “my mom paid extra for ultra thin lenses but the new ones are a lot thicker then the old ones. what's up ?”. The higher minus in your new prescription will add thickness. If the “ultra thin lenses” have RI higher than your old ones, this will reduce thickness. How does the size of your old and new frames compare? Those are the three relevant factors.

For both your old and new glasses, you can use the formula Melyssa provided to predict the theoretical edge thickness and compare it to the actual edge thickness. If you wish post your findings here. Could it be that you paid for “ultra thin lenses” but you received CR-39 lenses? Please don’t make any accusations until you assemble a thorough set of facts.

Revolver 02 May 2013, 09:43

Melyssa (no offense intended) says she's a -9.00 but in reality she's a -6.00 with -3.00 cylinder for astigmatism. Her spherical equivalent is indeed a -9.00 but the outer edge of the lens will be thicker where her cylinder occurs. A bit of a technical point, but nevertheless true. But we love her dearly, what's not to like about a minus correction in 45 big, bold, beautiful drop temples?

Melyssa 01 May 2013, 14:47


Unless high-index lenses get better in terms of technology, the higher the prescription, the thicker the lenses get. In my case, my prescription is -9.00 in both eyes and the CR39 lenses in all 45 pairs of my big, bold, and beautiful glasses range from 1/4 inch thick to 1/2 inch thick, depending on frame size. As an example, the midsized (for me) purple drop-temples I have on at this moment (a frame named Nicole, BTW), measure about 3/8 inch thick at the outer edges.

Astra 01 May 2013, 04:28

Nicole-15, you can estimate lens thickness at this page:

Astra 01 May 2013, 04:13

Nicole-15, If your acuity is corrected to 20/400 or better , this is not blind , your eyesight is not terrible.

Remember, most people would need glasses in their lifespan.

Astra 01 May 2013, 04:09

Re: nicole-15 01 May 2013, 03:27

thickness depends on

1. your prescription,

2. refractive index of material

3. distance from optical center of lens.

I think your prescription is moderate .

At high rx, they can use "myodisc", with smaller lenses which enable the lenses being made thin.

nicole-15 01 May 2013, 03:32

p.s., my mom paid extra for ultra thin lenses but the new ones are a lot thicker then the old ones. what's up ?

nicole-15 01 May 2013, 03:27

Hey guys!

So, I’m a 15 year old girl with terrible eyesite and I’m wanting to learn something about how perscriptions work. I got glasses in kindergarten and many times since then. Each time, the dr says my vision got worse and I get thicker glasses. My mom showed me my last 3 perscriptions and there isn’t any number that says thickness. How does the lab know how thick to make them? My forms have sphere, cylinder and axis. The cylinder and axis seem to stay the same so the sphere must be the thickness villin? But how do the numbers translate into thickness? Here are my numbers.

The oldest prescription is 9/6/2011 and says r.eye -8.25 l.eye -8.75.

The next is 9/2/2012 and it has r. -9.75 l. -10.25

The newest is from 4/16/2013. I couldn’t wait to September because I couldn’t see anything. My eyes changed so fast it like suddenly hit me. The dr said my eyes got way weaker so my glasses got way stronger to compensate. The form says r. -11.50 l. -12.00

I just got the glasses and they are unbelievably thick. But I’m curious as to how the sphere numbers tell the lab how thick to make the lens. Also, is it possible for my eyes to get so bad they can’t make a thick enough lens? is that when you start to go blind?

Thanks guys.

Carrie 27 Apr 2013, 17:56

The contacts my friend gave me are the single use 1 day disposable kind.

I have tried a strap for my glasses but I found it made my head itch after a few minutes.

I could, as you say, just go without correction during the gym sessions. My sight isn't so bad that I'm helpless without glasses. It just feels strange not wearing glasses - not seeing perfectly. I don't look at anything in particular when I go so I wouldn't be missing anything by not wearing glasses or contacts. I know how to operate the machines and could always take my glasses in with me in case I need to read any instructions.

It's several months before I'm due for an eye test but I might enquire about contacts when I go.

Cutting back on chocolate might be good way to prevent some of the unwanted bulge in the first place! It'll save me money as I'll be buying less chocolate and so won't need to go to the gym so often!

Soundmanpt 27 Apr 2013, 10:41


As long as the contacts are in the factory sealed package your fine with continuing wearing them whenever you want. But once you open them then you should be more careful about wearing them too long or often. By the way the way are they disposables? That date is more of a sell by date so they don't stay on a shelf too long before being sold.

Being that you only want contacts for working out and maybe certain other things I think you want to get disposables.

I understand your problem with sweating and your glasses sliding down, but another option or even a backup idea would be to get an elastic strap to hold your glasses in place.

Your prescription isn't that strong that you should need correction for working out, but I assume you need something to see the TV or if you read while your working out as some do?

Is it getting close to time for you to be making an appointment to get your eyes examined? I assume you know you can get your eyes examined for both your glasses as well as your contact and fitting at the same time.

Honestly unless your vision really changes I would hold off with buying any contacts until you finish using the ones you have at home. Then you can purchase some in your own rx.

Carrie 27 Apr 2013, 05:57

The disposable contacts my friend gave me have an expiry date of the end of June this year. If she or I had been wearing them every day they'd have been used up ages ago but as she doesn't use them any more and I prefer wearing glasses to contacts there's still quite a few contacts left. Is it important not to wear the contacts after the expiry date or is it ok to use them for a few weeks after?

I have actually thought about getting some contacts of my own just to wear when exercising at the gym or at home because my face gets sweaty and my glasses slide down which is annoying. Should I get disposables or reusables? I'm not very good about exercising and only go to the gym randomly. I walk quite a lot which has probably helped prevent me getting fat. Thankfully as my body has matured over the last couple of years I have transformed from a teenager with "puppy fat" become a petite woman with a noticeable bust and bum (nowhere near as amazing as Beyonce's gorgeous body). Unfortunately I can easily put weight on in the wrong places. Maybe my glasses magnify my belly and it just looks bigger to me!

Specs4ever 24 Apr 2013, 12:51

Oops, and I didn't even pick up the mistake with the plus base at first If the plus base is +0.5D the negative rear base needs to be -12.5, not -11.5. Whatever the end power is has to be the sum of all the powers.

ie: a -6D lens with a +2 front base curve needs to have a -8D rear curve

specs4ever 24 Apr 2013, 12:48

REd, I think you made a little mistake. In a negative lens with a negative base and of course a negative rear curve the total power is the sum of the 2 negatives. Your example of a -3 front base and a -15 rear base would give a lens with a power of -18D. For a -12 lens with a -3 front base the rear base would be -9D.

I don't mean to be picky - just trying to educate. And I think you actually knew this but just made a mistake when you put it on paper

REd 24 Apr 2013, 11:40


The 2 links below may help

Your new contacts base curve are in the middle of the expected range and conform to the size of your eye.

For glasses the base curve is not related to the size of your eye. It is selected to make your glasses visually appealing given your prescription. The sum of the base curve (front of lens) plus the back curve is equal to your prescription. Or is it the difference between the 2 curves.

For your minus 12 glasses with +0.5 base curve the back curve will be -11.5 for a difference of -12.

Had your optician selected -3 base curve then the back curve would be -15 to net at -12. The slope of the interior of your glasses would be much higher in this case compared to your actual glasses.

In conclusion I think your contacts will work well for you. Is that what you find? May I ask your age?

Your best explanation, if he comments, will be from Cactus Jack.

Filthy McNasty 24 Apr 2013, 11:12

They're different things.

In your glasses, the base curve is that of the front surface of the lens and is described in diopters.

In your contacts, the base curve is that of the back surface and is described in mm, representing the radius of the circle described by the rear curvature of the lens.

Ashley 24 Apr 2013, 11:01

I wonder if something is wrong with the base curve on my new contacts prescription. Until now I have only worn glasses. They have a power of -12 and a base curve of +0.5. I just got a contacts prescription. The power is -11 and the base curve is 8.4. I understand that the power is less because the contacts are closer to my eye, but should be the base curve be that far off?

Astra 24 Apr 2013, 02:17

Re: Clare 23 Apr 2013, 14:45

Denser lines are indication of higher refractive index. could be 1.67 or higher.

Clare 23 Apr 2013, 14:45

Soundmanpt - I doubt she has CR39 as I know where she got them from and its an expensive opticians! They look like the lines are closer together than mine, but its a wider frame, and I know our prescriptions are similar. My frame is narrower.

Juicebox - I'd always thought 1.6 made the lenses seem more attractive so have had them for a good few years now.

In the pair I currently have the lens edge is visible so I think its worth the extra but I'm no expert. How are you getting used to wearing glasses - are you more comfortable? As someone who never wore glasses, I'm quite happy to wear them most times but there are still occasions I definitely prefer contacts.

Soundmanpt 22 Apr 2013, 19:52

Juicebox and Clare

Really your prescriptions aren't that strong to really need thinner lenses, but it does make a bit of a difference if your frames are on the larger size because your both nearsighted and your lenses will always be thicker on the outter edges and the bigger the frame the thicker the lenses will seem. Ladies the only reason I could see spending the extra money for hi-index lenses would be if you were getting rimless or semi rimless frames. but most if not all of the little thickness you have should be pretty well covered with just plastic frames.


The person you were comparing glasses with sounds like she may have CR-39 lenses which are thicker than your lenses would be and if her frame is bigger then yours that will also influence the thickness on the edges.

juicebox 22 Apr 2013, 19:13


I was wondering about maybe getting higher index lenses because when I got my last pair - with a similar prescription to yours - they were quite a bit thicker than my last. are the 1.6 ones worth the extra money in your opinion? I only got new lenses put into my old pair this time as I'm still on the hunt for some new frames but it would be good to know for when I do find the elusive frames :)

Clare 22 Apr 2013, 15:33

I think lenses are fascinating. A friend and I have similar prescriptions but her frames are wider than mine and they seem to have more rings, closer together. I have 1.6 index for my -3 and -2.75 prescription, is she likely to have a higher index or is it the shape/size of the frame that makes them seem stronger?

Astra 22 Apr 2013, 01:07

Today I cleaned my room and found a magnifying glass.

I notice I can use the magnifying glass to see distant object in focus, but the image is inverted.

Soundmanpt 03 Apr 2013, 16:15


I just wanted back up what Cactus Jack was suggesting to you about maybe getting your families glasses from Zenni. ( I happen to be with a non-profit vision group that helps many low income people that can't afford eye exams and glasses and we have been using Zenni now for about 11 years. I have also helped many of my friends and their families save money by getting their glasses from Zenni as well. Also now even the opticians at the stores where I pickup donated glasses from are getting glasses from Zenni as well. With 5 of you all wearing substantial prescriptions I am sure you spend a good deal of money on glasses. Even with insurance most don't cover the extra cost of hi index lenses and that alone is often $70.00 or so. I think your husband and the child with the -4.00 rx can use the middle index which is about $19.00 exra and the other 2 kids and yourself probably should get the higher index (1.67) which is about $34.00 extra. So for your self and the 2 kids you can get your complete glasses for around $56.00 each and dad and the other child for about $35.00 each and that includes the AR coating as well.

Leonie 31 Mar 2013, 23:22

Cactus Jack --

from R -6.50 and L -7.25 to R -7.75 and L -8.50

From R -5.75 in both eyes to R -6.75 and L -7.00

From R -3.50 and L -3.25 to -4.00 in both eyes.

2 of them also have minor astigmatism.

Cactus Jack 31 Mar 2013, 23:02


Unfortunately, the minimization is caused by the laws of optical physics and there is just not very much that can be done about it. You did not mention the previous prescriptions, but the primary reason they look stronger is because they are. However, remember that you are very experienced with the effects of lenses and the vast majority of other people are not. Most people do not notice much about lens effects and only notice the frames.

If the prescriptions are not too complex, you might try order some low cost glasses with "standard" index lenses from an on line retailer such as Zenni and compare them. Single vision glasses can be as low as US$7.00 plus shipping, depending on frames and options. Let us know if you want to try it and need help.


Leonie 31 Mar 2013, 22:46

Cactus Jack -- Thanks. The optician had recommended high index lenses and edge polishing for the two older children, and I invested in them, but frankly the new glasses look stronger than the old ones despite the investment. I am disappointed. My children are 15, 13 and 9. Their prescriptions, in round numbers, are -8, -7 and -4. Mine is -9. My husband is -5.

Cactus Jack 31 Mar 2013, 22:21


Yes the minification that occurs with minus lenses works in both directions, looking out of the glasses and looking into the glasses. The amount of minification depends on the actual prescription and the vertex distance. Vertex distance is the distance from the front surface of the cornea and the back surface of the glasses lenses.

One of the things that causes an appearance of increased minification when looking at someone's glasses is what are called power rings, which are internal reflections of the edges of the lenses. Sometimes anti-reflective coating and higher index (thinner) lenses can help. Contact lenses are another way to minimize or eliminate minification for the wearer because they have a Vertex Distance of Zero, which will make the image size on the retina very close to that of a person who needs no vision correction.


Leonie 31 Mar 2013, 18:09

I'm nearsighted and so are my kids, all 3 of them. Every year they all get stronger glasses. I'm OK with that, and I understand that the lenses have to get thicker, but there is something I don't get. Why do their eyes get smaller every time the prescription changes? The older 2 have pretty small looking eyes by now. Must this be?

Cactus Jack 29 Mar 2013, 18:00


Significant cylinder such as you need, will affect the thickness of the glasses on the Axis of the cylinder. The axis of the cylinder is, by convention, the number of angular degrees the long axis of the cylinder is from the horizontal axis (0 or 180 degrees). The axis increases in the counter-clockwise direction as you look at the patient. 90 degrees is vertical. Traditionally, only axis between 0 and 179 or 1 and 180 degrees are used in optical prescriptions.

I am not a lens maker, but perhaps I can describe how they would make the lens for your left eye and give you an idea of what I think the lens will look like. I would ask some of our experts to comment if I did or did not describe the lens correctly.

1. Convert the prescription from + cylinder to - cylinder as I described a few posts back.

2. Select a len blank with a +12.00 base curve (the front surface) and probably a 0.00 or plano (flat) rear surface with a +2.50 add segment.

3. Grind away the back surface to make it slightly concave with a -0.75 sphere curve. The sphere correction is the difference between the front surface curvature and the back surface curvature.

4. Grind away more on the back surface to form a cylindrical shaped curvature of -5.25 with the long axis at 46 degrees and 0.00 on the short axis at 136 degrees. The final lens will be the thinnest at the 46 degree axis and thickest at the 136 degree axis.

The lens is going to be thick and a bit unusual looking. You might consider high index to make it thinner.

One of the biggest issues you will have is that there will be a significant difference in image size on the retina between the two eyes and it is likely that you will not have binocular vision because your brain may have difficulty matching the two images and just ignore one of them. Sometimes, people with significant differences in images size have problems with double vision because of the brains inability to fuse the two different size images.

If this becomes a problem you might be able to wear a contact lens (-9.50 or -10.00 perhaps) on your right eye and then wear glasses with both lenses in the +11 range.

The reason I suggest wearing a - lens on the right eye is that I think you would have problems with a + toric contact for your left eye, but that would probably give the best results if you could wear them. The closer your glasses could be to a low plus for both eyes, generally the better your overall vision.

Doing something like that requires an Eye Care Professional (ECP) with some imagination and understanding.

I don't know if Zenni will make glasses with that prescription. If they will it may be a relatively inexpensive way to fill the prescription and try it out. You may not have any good choice but to experiment some to find what works for you. You may have to settle for single vision glasses (no add) to get a low cost pair of glasses for trial purposes.

Could I ask a couple of questions?

1. Did your ECP mention anything about Kerataconus?

2. May I ask your age and where you live?

Again, we have some experienced ECPs in the group and I would appreciate any critiques of my suggestions or anything you could add to help James situation. I would suggest that amateur suggestions, including mine, may not be very useful in this situation.


James 29 Mar 2013, 14:45

Catus Jack

Thanks for your help Regarding my prescription for my left eye

OS - Left +6.00 +5.25 136 +2.50

Will my left lens be thick like a plus 11.25

This is a big change i have not ordered yet,but i am starting to have problems seeing so i need to soon.

I am going to order from the internet



Soundmanpt 20 Mar 2013, 14:52

I, Glasses

Not the most attractive looking glasses ever made, but I am sure as time goes on they will get better and more fashionable. The biggest feature is how much money that would save a very large part of the glasses wearing public since the majority of the population falls into those ranges of prescriptions.

I know one thing if there is a way to invest in this company and they have the patent on these glasses I would not hesitate to invest.

One thing for sure they would be perfect for anyone wanting to induce myopia as well at least up to -4.50.

I, Glasses 20 Mar 2013, 14:13

This item was in a recent New York Times' "Personal Tech" column. It is about "Adlens," very reasonably-priced ($80) glasses that adjust from about -4.5 to +3.5.

James 05 Mar 2013, 14:21

Cactus Jack

Thanks for your help.

This prescription is much stronger than before not had a test for 4 years.


OS Sphere +4.00, Cylinder +2.25 Axis 136

So plus or minus Cylinder make no difference to the thickness

 05 Mar 2013, 09:45

I got help in the post your prescribtion thread, so just ignore my post thanks :)

John S 05 Mar 2013, 09:38

A scan would be better.

What is your age, and is this your first prescription. Do you need help understanding the rx?

 05 Mar 2013, 08:16

if my last post was confusing, then I will post a picture of my prescription if you want

 05 Mar 2013, 07:41

Can anyone help with my prescription please?

R Sph Cyl Axis Prism Base/axis

+ . + .

0 1 2 5 0 0 2 5 0 3 5

L Sph Cyl Axis Prism Base/axis


Distance. . + .

0 4 0 0 0 0. 2 5 0 0 5


Cactus Jack 03 Mar 2013, 20:20


The first step in evaluating a prescription is to convert it to - cylinder format to better understand what is going on.

Before conversion, your prescription is:

OD Sphere +1.25, Cylinder 0.00 Axis N/A Add +2.50

OS Sphere +6.00, Cylinder +5.25 Axis 136

After conversion your prescription is:

OD Sphere +1.25, Cylinder 0.00 Axis N/A Add +2.50

OS Sphere +11.25, Cylinder -5.25 Axis 46 Add +2.50

The above two prescriptions are optically identical. If you order glasses with + cylinder, the lens maker will do the conversion above and make the lenses. The conversion procedure is to:

1. Algebraically add the cylinder to the sphere.

2. Change the sign on the cylinder.

3. Add or subtract 90 degrees to the axis so that the number falls between 0 and 180 degrees.

The choice of writing the prescription with + cylinder or - cylinder depends on the preferences of the examiner. The lens maker prefers - cylinder because he must grind away at the back side of the lens to create the cylinder correction. Grinding away the back side of the lens effectively reduces the + sphere correction with the long axis of the cylinder aligned with the 46 degree axis. By tradition the 0 axis is horizontal and the 90 degree axis is vertical. Axis angles are measured counter-clockwise from 0 as you face the patient.

Hope this helps. How does this prescription differ from your previous prescription.


James 03 Mar 2013, 12:43

This i my new prescription


OD - Right +1.25 0.00 0 +2.50

OS - Left +6.00 +5.25 136 +2.50

will my left lens be thick like a plus 11.25 as they are both plus the sph and cyl


this is a big change

Soundmanpt 03 Mar 2013, 12:09


So if you want them about the same as what you liked you can ask for 1.57 and if you want them even a bit thicker on the edges you can ask for 1.50 lenses. But before spending any money anywhere I suggest returning to where you got your glasses from and see if they will make the change at no additional cost to you. Simply tell them you were a somewhat disappointed that the lenses were so much thinner than your previous glasses and you really like the thicker look of your glasses. Customers are hard to come by these days and most retailers want to keep or make their customers as happy as possible so they will return. If they don't do this for you they probably know you will not be back again. i am pretty sure they will make the adjustment for you because they will want you to return when you need new glasses down the road.

If they don't provide what you want then look at the other options we have suggested to you.

JES 03 Mar 2013, 09:49


Thanx for all the good advice. I now found the prescription for my old glasses. The lenses were 1.57. Unfortunately, there seems to be a great difference between that and 1.61...

EyeTri 03 Mar 2013, 08:48


An internet firm that can replace your lenses for a reasonable price is

They have CR-39 (the lowest index) lenses for $30.00. They have changed lenses in several pairs of my glasses and I've always been satisfied.

Soundmanpt 02 Mar 2013, 09:52


You have several options, but since you seem to like the frame you got just not the fact that your lenses look weak you should go back to where you bought them from and ask that the lenses be changed. First of all they should not ever use a hi index lens without first asking you as in most cases there is an up charge for that thinner lens. As for finding a reason that you want your lenses to appear thicker just say you do acting and your character wears thicker glasses. Or just come out and say you prefer your glasses to look more meaningful. After all it is your hard earned money that paid for the glasses in the first place. By the way, I don't know how long you have had your new glasses but most optical stores will make changes within the first 60 - 90 days at no charge to you, so don't hold off. Your lens options are 1.50, which I think you would like from what you want your glasses to look like, 1.57, 1.61, and 1.67. There is also a newer and even thinner lens that I believe is 1.71.

Also like GL suggested you can go online and get glasses as well and Zenni offers the 1.50 lens for you prescription at no extra charge.

GL 02 Mar 2013, 08:35


Order online. You can get anything you want.

JES 02 Mar 2013, 02:50


Years ago I used to wear a large frame, because I liked power-rings and cut-in. My prescription has been a mild -3,5. But since I used a large Ray-Ban aviator frame, my glasses used to look really strong.

Two years ago I went for a small Henri Lloyd frame with a curvy lens that also looked quite strong. I thought it was a high-index lens but apparently it wasn't.

Last week, however, I received a new pair of large Ray-Ban aviators with a high-index 1.61 lens. The lenses look pathetic measuring a few millimeters at the edge and giving no cut-in at all. A huge disappointment for me.

What I would like to know is that is there a "medium-index" lens, that I wore in my small Henry Lloyd frame. The old glasses looked a lot stronger than my new ones.

I would feel quite embarrassed going back to the opticians, asking for a thicker lens...

Cactus Jack 01 Mar 2013, 19:16


Yes, easier than inducing myopia. However, it would be best if you ordered the same amount of prism in both eyes rather than having it all in one eye. Low BO prism has the same effect on eye convergence as reading.


Brooklynboy 01 Mar 2013, 13:20

I know that there are many people here that are experts on everything realted to eye and glasses. I have recenty ordered glasses from zenni with base out prism. Until now i didn't know they did that but when i saw that option on their website, I couldn't resist the urge of ordering glasses with prism out. My prescription is -5.5 or so. so for this order i order both eyes -5.5 and only one eye with 5 base out prism. I received the glasses today. (about 3 weeks after ordering) and I was thrilled to see the diference between both lenses. the lens with 5 base out prism is much thicker than the other. Now here is my question. I understand the reason why a person would have prescrition glasses with prism lens but it I begin to wear these glasses am I going to require prism prescription later?In other words, can a person induce prism?

Cactus Jack 26 Jan 2013, 22:11


You are right about the shape of your lenses having a significant effect on the edge thickness. The optical center (OC) of the lens is the thinnest point of a minus lens. Ideally, that should be on your central axis of vision with your eyes pointed straight ahead.

It is typical that the distance from the OC to the inner edge will be less than the distance from the OC to the outer edge. Therefore, the outer edge of a minus lens will be thicker than the inner edge if there is no prism involved.


Ellie 26 Jan 2013, 22:03

Anyone know why the lenses for correcting myopia are thicker on the outside edges than at the inside edges of my glasses? Does this have anything to do with the shape of my glasses? I don't have any prism.

 09 Dec 2012, 03:30

She claims to be 16 when I'm chatting with her. I just asked because her age seems to be inconsistent. I think Emily Gee and Nearsighted Emily are the same person.

varifocals 08 Dec 2012, 06:37

Sorry I missed a bit.

The Emily Gee of Lens chat is about 26 so not the same age as the lady in eyescene(22), a few lines back.

varifocals 08 Dec 2012, 06:32

Eye stein.

I think the Emily is the nice Emily Gee who is the moderator of lens chat.

The poor girl has had to endure some nasty comments about her poor vision & other things too.

She should be left alone .

Eyestein 08 Dec 2012, 05:52

Nearsighted Emily. Have you tried asking on yahoo?

 06 Dec 2012, 09:58

Who is Emily?

Likelenses 30 Nov 2012, 21:41

I Glasses

You could bump the prescription up to -4.5,and get CR 39 lenses.

You would enjoy the intense clarity of the extra power,as a bonus.

Minus25 30 Nov 2012, 12:12

I, can ask for plano fronts and 3 to 4mm center thickness, plus edge polish, or you can ask for the "thick look" and have the lab use thicker blanks.

I, Glasses 30 Nov 2012, 11:50

If I wanted to have a -3 Rx in a medium-sized pair of vintage rimless glasses (the 'octagonal' shape) appear as though the Rx were -5 or -6, what special techniques might I ask the optician to use?

mickey 19 Nov 2012, 17:22

I thought the same thing when I read nearsighted girl's post but it's OK either way.

 18 Nov 2012, 09:44

It's just you.

 17 Nov 2012, 12:50

Is it just me or Emily is posting as Nearsighted Girl now?

Nearsighted Girl 17 Nov 2012, 00:33

So, I'm really really nearsighted. I'm 22 and in grad school and I've worn glasses since kindergarten. And every year my glasses get stronger. So I just had an exam and guess what, more negative again which means thicker. The new prescription is -13.50. I hate the concentric circles that get bigger and more numerous with every new prescription. I've seen ads for Crizal lenses which are very expensive. I'm interested, but before shelling out, I need to know this: do they have the concentric circles or do they eliminate them? If anyone knows, pray tell.

Revolver 07 Oct 2012, 09:28


I assume that you are speaking of anti-reflective coatings, there are others such as anti-scratch etc. AR can be and is occasionally applied to both surfaces although front surface is the norm because of cost.

Backside AR greatly reduces reflections from the side and rear and produces a very pleasant result especially in stronger prescriptions. It is most commonly used in sunlenses, especially mirrored sunlenses, but of course in those cases it would not be applied to the front.

I have a delightful pair of #3 brown polarized prescription sunglasses, -1.00 OU, with backside AR and they are my favorites.

Himachala 07 Oct 2012, 06:08

can someone reply to my enquiry about coatings ?

Cactus Jack 05 Oct 2012, 10:29


I am happy to hear that you were able to get the problem resolved. Computer glasses are an excellent solution if you need to spend hours at the computer. I do something similar with clip on +1.50 magnifiers over my trifocals. That makes the distance segment just right for the display and the intermediate segment pretty good for reading. The nice thing about the bifocal style computer glasses and my clip ons is that you don't have to tilt your head up for extended periods to look through the intermediate segment at the display. If I do that very long, I get a crick in my neck.


The computer glasses Newly probably got, are standard bifocals. The power of the "distance" segment (most of the lens) is her distance Rx plus about +1.50 (to focus at her typical computer display working distance) and the lower reading segment is a +0.75 to +1.25 add to focus comfortably at her preferred reading distance. It is a simple, relatively low cost, solution that is pretty close to ideal for those of us who have little or no accommodation and need to spend long hours at a computer.

Bifocals for this purpose are easily ordered online from many retailers who don't offer trifocals.


gwgs 05 Oct 2012, 06:29

So you now have bi-focals? then 'newly blind', or trifocals?

Newly Blind 05 Oct 2012, 05:37

Hi everyone

Thanks for all the advice for the newly blind.

I have had a successful outcome from the optometrist when I returned to complain about my progressive lenses.

I saw a different ECP this time, just by good fortune and he was very sympathetic to my eye problems and glasses issues.

At times it sounded like he was quoting Cactus Jack verbatim. He took the time to explain all the different lenses and their pros and cons.

He agreed that my glasses were not suitable for my lifestyle and visual needs. In fact he said that no single pair of specs would be right for all occasions, so I voiced my extreme displeasure that this was not pointed out to me prior to handing over $800 of my hard earned cash.

Solution - at no further cost to me, a pair of computer glasses with the bottom for reading and the top for the computer, provided at no extra charge.

Now I have the best of both worlds and all is good.

I lived happily ever after with my new specs (x2)


Himachala 03 Oct 2012, 19:33

May I ask, what is the common practice of applying coatings on glasses lenses ? Do we apply coatings on the front side or the back side or both sides of the lenses ?

Jo 01 Oct 2012, 03:17

Jarred - I would have to agree with you on trifocals - I've been reading this site from an afar for quite a while, without posting, but feel inclined to throw my two pence worth of opinion in;

I've also tried all forms that you've listed, having progressed from bi-focals my optician said to try varifocals, but only being 34 years old, I had only just got over having to wear bifocals at such a young age so when I was having trouble reading things at a mid range I went to my optician who recommended varifocals as this would eliminate the two segments areas which I didn't really want to be visible, and he said it would integrate much better with my day to day life - driving, being a PA to a busy chairman, etc.

However I didn't really like the varifocals as I could never really know/guess where the mid part was and it took a while for my eyes to grow accustomed to everything being integrated into one lens. I am now happily wearing tri-focals, and am very pleased with them compared with the varifocals, and have had several compliments on the train on the way into work from men, as well as a male colleague at work saying how good my new frames look on me - definitely worth a try for all those are debating the toss between the two.

Jarred 29 Sep 2012, 13:46

Hi Newley

I've been through the whole process of Varifocals/Bifocals/Trifocals. And in my opinion Trifocals give the best all-round vision for an active person. I drive, use the computer are generally active and Trifocals by far out perform any other lens I've tried and that includes the hyper expensive customised varifocals.

With a decent AR coating the lines don't stand out that much and its interesting how quickly you adapt to them and then don't notice the lines.

The last pair of $1000 customised varifocals I was told would be perfect, I didn’t even leave the shop with. They were so bad I assumed there was something wrong with them, which apparently turned out not to be the case. They had such a small area of clear focus distant, near or close that they were effectively useless.

Cactus Jack 29 Sep 2012, 10:27


I really think you need to strongly consider trifocals, but don't wait too long to have that discussion with the optician. The meter is running.

You have three choices in trifocals. FT-28 is the most commonly prescribed, FT-35 is generally a bit harder to get, and Executive Trifocals (full width) are even harder, if they are available at all.

If you are up on your trigonometry functions you can calculate the approximate field of view by treating the problem at two right triangles, long side to long side, with the apex at about 25 mm from the glasses (about the center of the eyeball) as the long side and 1/2 the width of the lens segment as the short side. Once you know the angle between the long side and the hypotenuse, you can extend the long side to the focal plane and calculate the length of the short side which is 1/2 the theoretical field of view.

Rather than do all that, I can just measure my field of view with FT-28 trifocals and go from there. My field of view in the Reading segment is about 12 inches or 30 cm. I use the Intermediate segment for the computer display (20 inch (51 cm) @ 26 inches (66 cm)) and the 17 inch width (43 cm) fits within the segment. These glasses are +3.00 add in the reading segment and +1.50 in the intermediate. Different adds will result in slightly different fields of view. The fields of view with FT-35 would be about 20 to 25% wider. Executive Trifocals have full width of the glasses and the same field of view as the distance segment. However, Executive Trifocals are a nuisance because you can't see around the reading or intermediate segments so it eliminates peripheral vision clues which are very important to avoiding nasty surprises. Most people who wore them did not leave their desk with them on, but changed to FT bi or trifocals.

I would strongly suggest that you try FT-28s and see how they work for you before going wider. You can find online retailers who offer trifocals, but you may have to look beyond the the obvious ones.

In answer to your question about reading very small print using stronger plus lenses without changing the focus distance. Neither Isaac or I had/have any idea how to do that. Recall how magnifying lenses work. You might find something like the Bausch & Lomb Magna-Page magnifiers useful. They are very inexpensive and are available in several sizes. I found them online for about US$9.00. Many office supply stores have them. For more precise work, you may recall the "binocular" glasses worn by surgeons performing microsurgery so they can see tiny tissue structures at near arms length.

There are lots of vision tools out there, but some are not cheap and take some getting used to.

Hope this helps.


Newly Blind 29 Sep 2012, 08:45

Another question, sorry.

To what extent can the strength of reading glasses be increased, without changing the focussing distance?

I want/need to be able to read really small print, but holding the subject at a normal reading distance. When determining my prescription the ECP just tests normal sized newspaper text at normal reading distance, but this does not correlate with all visual requirements.

Can this be achieved, with the same pair of specs, and avoiding having to hold even normal sized print at your nose to see it?

I imagine Cactus Jack and Isaac Newton have some equations for this!



Newly Blind 29 Sep 2012, 07:53

G'day everyone

This is a brief update on the saga of my new glasses.

I have not gone back to the ECP yet as I have been busy with other stuff. However, I have been wearing the glasses when I am out and about and have not tripped over again or had any other accidents so I am adapting to the progressive nature of the lens. I am really enjoying not having to take off my reading glasses on average every 28 seconds during my waking hours. The glasses are fine for incidental reading/near vision throughout the day (checking my watch/mobile phone, looking at prices at the supermarket etc). The intermediate section is of no use to anything though, as I can only see a tiny amount of text at any one time, so it's much more of a hinderance than a help.

But, my original issues persist. I can't study, write a research paper, and read textbooks with glasses with such a limited field of view.

I have been thinking about some of Cactus Jack's advice and have a few questions that I woud be grateful for advice on before I go back to the ECP.

If i decide to go down the path of trifocals or bifocals, is there a way to calculate the width of your field of view with different lenses - FT 35's vs Ft 28's? I would really like to know if these lenses would allow me to see the entire width of the my laptop screen without having to move either my head or the laptop sideways in order see the entire width of the screen (not practical options!!). I have the same question in regards to the reading segment. I need to be able to read pages of textbooks without moving the book all the time. How do i work out which lenses, if any, fulfil my wishlist?

Thanks again in advance for sharing your wisdom and experience in these issues.



Julian 18 Sep 2012, 05:27

Filthy: yes, I always find lenses of that kind particularly interesting (and difficult to estimate the Rx)

Filthy McNasty 17 Sep 2012, 19:41

I will. I'll set up something on-line. Stay tuned. They are really interesting lenses. I love that they are plus in one meridian and minus in the perpendicular meridian.

Asdoo 17 Sep 2012, 18:13

Filthy McNasty

Can you please post pictures of your GOC glasses? I've always been interested in astigmatism as well.

Filthy McNasty 17 Sep 2012, 18:03


Many thanks for your feedback. I understand perfectly that the calculations even doen correctly do not always deliver a perfect result, and that it's a risk, but we'll see what happens. And you're right about my terminology; I stand corrected.

I'll let you know how it goes.

Cactus Jack 17 Sep 2012, 17:04


It appears that you have done the calculations correctly and in the right order. The glasses to CL vertex distance adjustment is done on what would be the refracted Rx or the resulting glasses Rx. The only thing I would state differently is this statement:

Compensating for vertex distance, the glasses are:

+3.25 -6.50 x 120

+3.00 -6.50 x 70

I like to think that the vertex distance adjustment yields the adjusted CL power of the corrective glasses at the surface of the cornea.

The fact that you did the calculations correctly, does not necessarily mean that the resulting combination will be comfortable or satisfactory. Basically we have made calculations of microscopic precision using formulas and data of doubtful accuracy. So as they say in advertisements, "Your results may vary".

Please let us know how this all works out in detail.


Filthy McNasty 17 Sep 2012, 13:56

Sorry, meant to post to GOC thread.

Filthy McNasty 17 Sep 2012, 13:42

Cactus, I am an experimenter at heart. I have always been fascinated with high astigmatism, and have decided to try GOC for it (I know my contact lens size, just not the Rx). See what you think of my reasoning:

My natural Rx is:

+1.25 -0.25 x 120

+1.00 -0.25 x 70

I have had glasses made that are:

+3.25 -7.00 x 120

+3.00 -7.00 x 70

Compensating for vertex distance, the glasses are:

+3.25 -6.50 x 120

+3.00 -6.50 x 70

but my prescription needs to be removed, leaving, as the spectacle Rx to be compensated for:

+2.00 -6.25 x 120

+2.00 -6.25 x 70

So the contact prescription would be:

-2.00 +6.25 x 120

-2.00 +6.25 x 70

or, converting to the proper notation:

+4.25 -6.25 x 30

+4.25 -6.25 x 160

Have I done this right, and in the right order? I am specifically thinking of the vertex distance compensation step, which makes a difference to the final value depending on when in the calculation you apply it.

Much obliged for your thoughts.

Newly Blind 14 Sep 2012, 00:52

Thanks Cactus.

I definitely have to practice what to say. I am glad you are loving your new car. I think that ECPs have a greater responsibility thatn a car salesman in helping the customer to select an appropriate product, since it is actually a healthcare/medical issue, not just consumer choice. In Australia, everyone can get their eyes tested for free at the optometrist under the public healthcare system. Part of the deal then is surely to sell glasses that fit the visual needs of the pt.

I might be incommunicado for a few weeks while I write an essay, but I will report back to Eyescence in due course.


Cactus Jack 13 Sep 2012, 23:13


It is hard to say from half way around the world, but my SWAG is that about 40% is your needing to learn about and adjust to the compromises you need to make to function in a new and strange visual environment. As good as they are compared to the alternative, IOLs simply can't give you all the capabilities your natural crystalline lenses can when you are in your 20s. The fact that you did not know about that is NOT YOUR FAULT. You simply did not know what you needed to know. The other 60% is the failure on the part of the ECPs to analyze your visual needs (20%), explain the pros and cons of IOLs and the pros and cons of progressive lenses so you understood them (20%) and failure to consider the psychological trauma you had experienced and the visual environment you had been suddenly thrust into (20%). They are supposed to be professionals and know their business. The business basics are really quite simple. They advised you to purchase goods and services that you did not understand and were not familiar with and then failed to advise you the "benefits" and "limitations" of those goods and services. They are supposed to be the experts on their products and services, you are the neophyte. You situation was little different from the ECP that sells contact lenses. By custom, training for inserting the CL, taking them out, their care and your personal hygiene in handling the lenses is part of the deal. Perhaps the thoughts of the $800 clouded their judgement. Who knows for sure at this point.

They have blown the very important opportunity to make a good 1st impression and you are having a form of buyers remorse, with good justification.

I understand what you are going though. I recently had the exact opposite experience with a recent purchase of a new Toyota Prius V Hybrid. I have been operating complex and sophisticated vehicles for about 65 years, but Hybrids are a bit different for regular cars. In my case the dealer and the manufacturer made sure I understood the differences and made sure I understood what to expect from the car. It turned out that they had under-promissed and over-delivered. The result is that I am delighted with my purchase and pleased with myself for being so clever, and throughly enjoying my infrequent visits to the gas station.

On the theory that you get more flies with honey than with vinegar, I would suggest that you go back and tell the optometrist that you are having problems with the glasses. I am almost certain the his first response is that you need more time to adjust to them. You can counter that by having a list of your experiences with them in your visual environment. It is a lot different than the visual environment of a 60 year old who has worn glasses for years and has now had cataract surgery. Try to be sure that your visual environment is well understood. You might even want to take a book or at least have the numbers for your reading distance and your working distance from the computer display. Try to explain your need for a wider visual field for both near and intermediate work. You might want to mention that you like the idea of vari-focal lenses, but you are wondering if these lenses are the best suited for your needs.

One thing to remember is that it is unlikely that the ECP has actual experience with suddenly becoming a cataract patient with IOLs. He should know the theory and he may have fitted older patients with glasses after cataract surgery, but he has no personal experience. You have to help him understand your visual needs and there is no way he can see what you see. Think about how to explain it.

The closer is that you believe these glasses are not suited to your needs and you need a better solution than he has provided so far. He may suggest more time to adapt. Your response needs to be some form of "How long? Worst case". You can decide if that is reasonable or not. If not, negotiate. Just remember, "DO NOT NEGOTIATE WITH YOURSELF". He is the expert and fundamentally, you have paid him to solve the problem. If he can't, you need your money back so you can consult another ECP. (Be careful how you play that last card. It needs to be a simple statement of fact and not an emotional outburst.)

If he is a smart businessman, part of the $800 was contingency money to solve any expected and unexpected problems. Given your situation, he should have expected that there would be some problems and or remakes of the glasses and allowed for it. If he didn't, that should not be your problem. He may try to negotiate for more money, but do not give ground easily and do not let emotions get into the act.

Before you go back to see him, think this through like you were rehearing a play. If you can, get a friend to role play with you. The scenario may not develop exactly as you visualize, but it is better than going into the negotiations with out a plan.

One of the problems with Business Plans, Battle Plans, or Negotiation Plans is that the 2nd most important party in the plan has not read it or agreed to it. By that, I mean your customers, the enemy, or your opponent in the above plans. A good commander knows that a Battle Plan goes out the window when the first shot is fired. If he knows his business, he knows that will happen and is ready for it with alternatives, resources, and reserves. Good Negotiators understand that and unlike military commanders, look for win-win opportunities.



GOCer 13 Sep 2012, 22:09

SZ6 - did you have to make a note to glassesshop to get 1.5 index? I noticed if you select it on the order page the lens power only goes up to -6

Newly Blind 13 Sep 2012, 18:54

Thanks Cactus,

Have you thought of getting some kind of pay pal account for donations??

In your honest opinion, are my problems due to not adjusting to the glasses, or the glasses being wrong? From what you have said i am pretty sure it's the latter, but I need to be sure so that when i go back to the store, and if they just tell me that i need to give it more time to adjust, i can argue my case.

I won't be handing over any more cash for glasses until i have had a good chat with the optometrist and am convinced that they fully understand my issues and can help. I will shop around. Yes there are plenty of ECPs around here



Newly Blind 13 Sep 2012, 18:35

Thanks for the advice Soundmampt

To answer your question, I didn't sleep at night for months!! In hindsight i should have demnanded an appt with the specialist much sooner. But I was too terrified and sleep deprived and stressed out to think clearly and be proactive about it.


Soundmanpt 13 Sep 2012, 12:28


I have been following your situation with interest. I can tell you Cactus Jack is very good with his knowledge of optics and in your case he has personal knowledge as well. So there was little I could add that would have been as good as he has been advising you. It did catch my eye as well when you said that your glasses cost some $800.00. That is excessive to say the least. Like Cactus Jack stated most all good optical companies such as Pearle and Lenscrafters, and many others give you between 60 and 90 days to wear your glasses and if your not happy with them you can return them for a full refund. I would be on my way back to where you got them and just tell them they aren't right and you want your money back. Of course be nice about it unless they give you trouble over it. As suggested you then have several much less expensive options that you can try. Testing out some over the counter readers should work even if for the time being you may need 2 different prescriptions, one for reading up close like a book and one that is slightly weaker for working on the computer. The other option is to go on line at "" and order glasses from there. Actually you can find many for under $60.00 including shipping.

I'm sure what has happened to you has been very scary for you. To always have had perfect vision and suddenly having your vision become so bad so fast i'm sure you did think you were going blind. I am really shocked that any optometrist couldn't tell what was wrong is even more amazing to me. Then all the time to get in to find out what was happening, I have no idea how you were able to sleep at night from worry?

Cactus Jack 13 Sep 2012, 11:16


Almost there. Could I suggest Newly Enlightened?

Single vision glasses have the same Rx all over.

There are several types of bifocals but the most common one these days are what are called Flat Top bifocals. The most common of the Flat Tops are called 28 mm Flat Tops, but you can often get 35 mm Flat Tops as an option. It is a little hard to describe but lets try this. Imagine a single vision glasses lens, now imagine another lens about 28 mm in diameter that has had the top 4-5 mm cut off creating a flat side. Now place that lens with the flat side up on the first lens with the bottom of the 28 mm lens just even with the edge of the first lens. Voila, a bifocal with a FT-28 reading segment. The power the reading segment is added to the power of the first lens, thus an "add".

For a trifocal, Imagine the above reading segment with line drawn across it about 7 mm below the flat top and parallel to it. That becomes the intermediate segment and it is typically 1/2 the power of the reading segment, but other powers are available for special needs.

Believe it or not, there is also such a thing as a Quadrifocal. It is exactly like a trifocal (of bifocal for that matter) except it has a small reading segment at the top of the main lens. It is made for people who have to read small text above their eye level such as electricians working on electrical panels.

Progressives are a variation on the bifocals or trifocals with the only purpose of hiding the dreaded lines for vanity reasons. The have NO optical benefit - well maybe one tiny one which I will explain in a moment. The were created because bifocals or trifocals were only for "old" people, "over 40". Ideally, the reading segment and transition corridor are shaped like the bottom and neck of an hour-glass except the neck (transition corridor) is a bit wider than a typical hour-glass. The edges of this hour glass shape are blended into the main lens so that it is not obvious that it exists when looking straight at the person. A person familiar with glasses can easily spot progressives from the side or back my noting the distortion if they can see beside the persons face and through the lens. Generally, the size of the reading segment and corridor are smaller than bi or trifocals because the blending uses up more space that the thin lines across and around the lenses in regular bi or trifocals.

The tiny advantage of progressives occurs in the transition corridor. The ADD gradually increases from 0.00 at the top to the power of the reading segment at the bottom. (+2.50 in your Rx). There is only so much space for the transition so the higher the ADD the faster the change and the smaller the area of useful focus for any intermediate focus distance.

I think most people who like progressives started wearing them when they only needed a small ADD of +1.00 or +1.25. As their ADD slowly increased their skills increased and they probably had little need for the lens powers in the corridor.

I tried progressives after wearing trifocals for several years and did not like them because finding a focus point in the corridor was a pain and the area of useful focus was too small to be really helpful. I find that I use the intermediate segment about as much as I use the reading segment. If I have to read a lot or want to read in bed, I prefer single vision Rx reading glasses in a cheap, but durable frame. I think I paid US$38 for the last pair I got about 7-8 years ago.

How do you know what you really need. Unfortunately, that comes with experience, but perhaps the descriptions above may help. One thing to remember is that selling optical services and glasses are businesses and they need to make money to be there, They make the most profit from up-selling. High fashion designer frames, super thin lenses, progressives rather than bifocals or trifocals, and special coatings and tints. None of these things are harmful and in some instances worth the extra cost, However with your Rx and the IOLs (believe it or not they typically transmit light better than your natural lens), you obviously NEED multi-focals of some sort and perhaps UV and/or AR coatings. You probably NEED sunglasses of some sort or transition lenses. The rest is strictly up to you.

One possibility that I have not mentioned is wearing a contact for intermediate vision on one eye to give you mono vision. Lots of people do it and I suspect you could function quite well in most situations with mono vision and some Rx reading glasses.

The only real way to learn about all this stuff is to read up on it and try it. I have worn glasses for 60 years and am still learning. I don't know exactly where you live in Australia, but I suspect if you live in a major city, there are plenty of ECPs around. Some are more willing to listen and help than others, you just have to find them. The first step in finding a "keeper" is their willingness to listen. They get to look at you and your problems for a few minutes, you get to look at your problems every waking minute, all day long. Some will think you don't know anything about vision and its correction. Unfortunately, they are often right. None of this science stuff is taught in school any more. Two small tips. Optometrists are better at fitting glasses and contact than ophthalmologists because that is all they do. Independents tend to be more through than big operations, but that is not a hard and fast rule.

Cactus - Some wisdom and lots of experience, some of it expensive.

SZ6 13 Sep 2012, 09:28

gwgs, yeah, the Rx is -10 and change with a touch of astigmatism. The lenses are 1.5 index. It seems like they are close to the maximum thickness of the blanks... glassesshop might have use 15mm blanks for these - not sure.

Newly Blind 13 Sep 2012, 09:24

Hi Cactus

Thanks for that. A qstn before i go to bed.

Have i got this right:

Single vision reading glasses have the same prescription all over. Progressives are mostly for distance, with a narrow 'corridor' in the middle for intermediate, and then a narrow coridor below that for reading. These corridors do not extend all the way across the lens from left to right - that's why it is blurry on the edges (ie the blurriness is not due to my head being in the wrong position or looking through the wrong part of the glasses - it is because the glasses are simply not made to focus on what I need to focus on).

So are trifocals somewhere in btwn - in that the reading part does not go all the way across from left to right, but it is wider than for progressives?

How do you know what you will be able to see before you order the glasses (either in person at the shop or online)? How do you know if the reading portion will be wide enough to meet your needs?

Even if someone explains it, you really need to experience it for yourself (broken ribs and all hey?!)to judge if it is appropriate.

I am just not sure how to find someone to make the perfect glasses for me, and call me old fashioned, but i would like to talk through the issues and let a real person take the measurements before purchasing the specs. By the way, my optician did take lots of measurements and put texta dots on the lenses etc, and advised me that some frames i liked would not be large enough for a progressive lens. So they were not completely negligent!

I hope i am not sounding like a drama queen over this. I just had no freakin idea it was so complicated. I thought you have the eye test, you choose the frames, they make the glasses according to the results of the test, you put the new glasses on,and bingo, you can see again. I didn't know i had to do so much homework to sort it out for myself!!!!!

It seems to me that in all respects I should defer to Cactus Jack's infinite wisdom!

Good night from Australia.

Cactus Jack 13 Sep 2012, 06:10


Spot On! Seeing is the most important thing. Never mind what it takes to do it or what other people think. Their day will come. Yours just came a little sooner than most. Glasses are just a tool and if they happen to enhance your appearance, that is just a positive side benefit.

Thanks for the complement. I would like to find a way to get paid, but I haven't figured out how - yet.

Part of the problem you are having is that you have not learned all the tricks yet. Having perfect eyesight all your life and then suddenly nearly losing your vision is tough. Most people have vision problems develop slowly and learn and adapt to using their "vision tools" gradually. You got "dropped on your head" or knee as the case my be. Been there and done that.

Progressive lenses have their limitations (even the best ones) and you have to learn to use them by moving your head rather than your eyes. One thing, with any multi-focal lens, you need to select frames that are larger in the vertical direction than is sometimes fashionable. You need room for the other lenses and in progressives, the transition AND the lenses. If the frame you select is not tall enough, guess what gets cut off when they cut the large round blank to fit the frame.

Speaking of learning how to use your glasses, be thankful that you are living in a time where cataract surgery and IOLs are available and can work for most people. The discovery that you could have plastic in your eyes for years without adverse events was made a few years after World War II (late 1940s and 1950s). Some British fighter pilots were discovered to have small pieces of Perspex or Plexiglas inside their eyes and it did not affect their vision. The small pieces came from bullet shattered canopies hit by enemy fire. Their eyes had healed after the event with no particular problems. Before this discovery, the ONLY way a person could see after removal of a crystalline lens was by wearing very strong (+15 or more) glasses.

Talk about a very steep learning curve. In many ways, high plus glasses act like binoculars, you have little or no peripheral vision. One of our members, who is naturally very hyperopic, commented that his high plus glasses limited his peripheral vision to the point where when he rode a train, he could only see the person directly across from him. He could not see anyone sitting on either side without turning his head. Of course, he could not drive. Imagine the curb and stair problems he has.

BTW, trifocals and bifocals have their problems too. With a +2.50 reading add, everything beyond 50 cm or about 19 inches is very blurry through that segment. Curbs or stair steps with little contrast can get you if you are not paying attention (I wonder how I know that. Cracked rib anyone?). If the reading segment is not too wide, you can sort of see around it with your peripheral vision. They make an Executive Bifocal or Trifocal lens where the segments go all the way across the lens, but you rarely saw anyone wearing them away from their desk, for good reason.

Another long winded post. It has been said that I have a degree in BS, also an MS (more of the same) and am working on my PhD (piled higher and deeper). When I get that that, you can call me Professor.


gwgs 13 Sep 2012, 02:59

SZ6 - it sure is a compliment. They are stunning, do I recall correctly that your prescription is 'just' -10.25 to get this immense lens thickness?

What type of lenses did you request? Surely they must be 1.5 or 1.54 index?

Newly Blind 13 Sep 2012, 02:40

Gosh Cactus Jack, what can I say? I think you need to start charging for your advice! And I know you said we are on a first name basis around here but I reckon 'Professor Cactus' would be appropriate.

It sounds like you have had enough vision problems of your own to deal with. I became quite an expert on eye diseases/cataracts too while trying to work out what was going on with my eyes but I am not yet up to speed on lenses and glasses. So thanks for the crash course and the moral and practical support/advice!

I will definitely go back to the optometrist and discuss the matter with them. They did seem genuinely helpful and invested a lot of time in helping me choose my frames ( i think i tried on every pair in the shop after coming in every day for a week). Then if they don't cooperate and address my issues, I will get angry and demand my money back.

Ultimately I just bloody well want to be able to see, and that is far more important than the aesthetics of the glasses. So I might give trifocals a go.

I have been using over the counter specs for a while (until my eyes stabilised after the surgery) so i can continue with that for the time being.

On another issue, and i am almost too embarrassed to admit it (yes even with a fake internet identity!!!) but I tripped over the gutter/curb the first time i left the house with my new glasses. I was trying so hard to just look straight ahead thru the upper part of the lens that I didn't look down at the footpath at all. Result = one battered and bruised knee, one very sore elbow, and 2 grazed palms. I think I have adjusted now, so if i do try the trifocals, at least i will have this aspect of wearing them sorted out!!!!

Cheers for now


Cactus Jack 12 Sep 2012, 23:29

Newly Blind,

Again, I must apologize. Some of my suggestions need to be predicated on factors related to gender and I failed to ask.

Thank you for sharing your story with us. That was a truly terrifying and traumatic experience. It is very unusual for cataracts to develop so quickly. Cataracts develop in the crystalline lens of the eye. The crystalline lens is a transparent protein that has the consistency of gelatin dessert when you are young and over time it becomes thicker (presbyopia) and can develop problems such as cataract. There are several types of cataracts. The most common one is where the clouding of the crystalline lens happens very slowly. Another is where the crystalline lens becomes crystallized like shattered glass. In my case, I had presbyopia because of age and my lenses developed something similar to the crystallization except the pieces were large and I saw 5 or 6 images that were close together. The first time I saw it, I was driving home from work and I saw multiple freeway signs with both eyes, like looking through a Kaleidoscope except the several images were not colored. It scared the hell out of me.

I hope you will forgive me for relating my own experiences. I sense that you are undergoing some psychological adjustment to your new situation and one of the benefits of these forums is to help you realize that you are not alone with vision problems and there are others who have experienced traumatic vision situations and have managed to deal with them. You are not alone and knowledge is the best elixir of all.

I had similar problems with the diagnosis because it turned out that the problem was intermittent and after a period of rest, the pieces would apparently fit back together and I would see only one image with each eye. Usually, by the time I got to the ophthalmologists office, there was nothing to see. With some experimentation, I discovered that I could cause the problem by reading or using the computer for a long time. I made a deal with the ophthalmologist to sit in his reception area and read until it happened. It did and he took to the exam room. When he looked into my eyes, the identified the problem instantly and said the fix was the same as a normal cataract, take the bad lenses out and put in IOLs.

Back to your situation.

Yes, trifocals have the dreaded lines. You actually have 3 different lenses in your glasses, the basic distance lens and two other strength + lenses molded into the glasses in the front surface. Unfortunately, there have to be lines. A little more about that in a moment.

What are your options? I don't know what the laws are in Australia, but I think you need to go back to the glasses vendor and demand your money back. Essentially, the glasses provided are not wearable. I would not accept any offer of remaking them or replacing them with other progressives or trifocals. You need to find another optician who understands your needs and limitations. It is not uncommon for their to be an adaptation period to new glasses. Often that involves accommodation by a persons crystalline lenses and ciliary muscles. After cataract surgery, a person has VERY limited ability to adapt to anything other than perfectly made glasses that fit their exact visual needs. An experienced professional should have known those limitations.

You may have noticed in another post that Julian and I discussed your experience. As was said in that post, we didn't know the going price for top grade progressives in Australia, but unless you got very expensive designer frames, you paid too much for the quality of the lenses you got and the professional services you have received. There may be other top brands, but Rodenstock, Zeiss, and Varilux lenses come to mind as making exceptionally good progressives. However, even the best have limitations.

Step 1 is to get a refund of your money. I assume you have some glasses you can go back to until you can get this resolved or with your low Rx, you may be able to get by with some +1.50 readers for the computer and +2.50 readers for closer work. The formula for focal distance is something you need to know for selecting Over the counter readers. You have no ability to focus or accommodate so just measure the working distance in cm or inches and divide it into 100 cm or 39.37 inches. The resulting number is the power lens you need to focus at that distance. For example, if you need to comfortably view a computer display at 60 cm or 23 inches, you need a +1.66 lens, which you can't buy. You can get either a +1.50 lens which focuses a little farther away or a +1.75 lens that focuses a little closer.

I would like to suggest something for you to consider as a low cost experiment, if nothing else, trying to get some glasses on line. You can probably get some pretty good progressives from Zenni Optical for less than $100 depending on the frames and options you choose. One thing to remember, frames are frames and they really don't cost much to make. Famous Designer frames have a HUGE markup, We can tell you how to order on-line. It might be a cheap way to see if they work any better. I don't know if you can return them for refund if they are not satisfactory. (Soundmanpt I would appreciate your thoughts on this).

I think you ought to consider getting some trifocals for functional purposes. They will give you a much wider in focus field of view in each of the segments and little or no distortion. I am writing this looking thru the intermediate lens of my FT-28 (Flat Top - 28 mm wide) trifocals and I can see the full width of my display. With your Rx, you don't need any high index lenses. Either CR-39 with an Index of Refraction of about 1.50 gives exceptional optical performance or perhaps polycarbonate, which is slightly thinner with a bit higher IR. An Anti-Reflective coating would be useful in making the lenses less visible, if it is not too expensive. There is no need to pay for super thin lenses, your lenses will not be very thick anyway. I don't believe Zenni offers trifocals, but I believe there are other on line retailers that do at reasonable cost.

If you are worried about what others might say about a person of your age needing trifocals, don't be. Few people will notice and all you have to say is that you developed an eye condition where you needed cataract surgery at a very early age. One of the results is that you have no ability to focus without help and at least you don't have to wear very thick cataract glasses like they used to. Remember, you wear glasses for YOUR benefit, not theirs.

You might also consider some progressives for casual and social wear. What you want to pay is up to you, but think hard about getting good value for your money. Higher priced frames do not necessarily last longer than lower cost frames. The most important thing is the lenses and how well you see with them.

BTW, there is a bright side of all this. You may have noticed that there is a lot of discussion about changing prescriptions. It is not uncommon for younger people to need new glasses at least every year and occasionally more often. It is highly unlikely that your Rx will change much from here on. I can still see clearly with the Rx I got after cataract surgery in 2001. There have been other changes unrelated to my basic Rx and I have occasionally changed frames for variety.

Again, I apologize for being so long winded, but I want to help you understand. Please let us know what you want to do and please do not hesitate to ask questions if all this is not clear to you and please keep us posted on your progress.


Newly Blind 12 Sep 2012, 19:31

Thanks Cactus Jack, for that thesis on my new glasses.

From what I was told, the bottom of my glasses would be for reading and the top for distance. None of this nonsense that there would only be a tiny sliver of lens for reading - I thought the whole bottom section would be like reading glasses.

Do trifocals have the dreaded 'line' or does it just depend on how much you pay?

Also I don't think it is a matter of me adjusting to the specs - even when i very very slowly move my head up and down to get the perfect vertical position for what i am looking at, there is no option to look even a tiny bit left or right for it to be in focus.

What are my options now? Should i go back and ask for trifocals? Will they charge me? Do I have any rights at all?

On another issue, if anyone is interested, is the story of cataracts. CJ - I do think my moniker is accurate as i went blind very suddenly from the cataracts and had perfect near and distance vision before that (oh they were the days!!!!!), so I do think I am newly blind! But I get your point!

It seemed to me that on one weeknd I noticed that I was very sensitive to lights, driving towards the sun, into oncoming headlights, fluoro lights at the shops, and finding it impossible to have the right lighting for reading. I swear this all happened out of nowhere. So I booked an appointment with the optometrist. I had never had an eye test before so was really scared and new something was badly wrong. I had to wait a week or so before the appt and the symptoms continued to deteriorate rapidly. When the time came, the optometrist did not know what was wrong with my eyes, if they would get worse, or if they could be fixed. That very much allayed my fears (NOT!!!!). He referred me to the opthalmologist and i had to wait 6 wks for that appt. In the meantime, I became so blind i could not drive at all, i couldnt see the tv, read the paper, or see the computer screen. And I had no idea what was wrong. UNtil such a time as it became impossible, i googled my symptoms to try to self diagnose, and terrified myself that i had some kind of incurable, progressive eye disease (which my opthalmologist specialised in which i took as 'evience'of what was wrong with me). I went to work every day and just pretended to function when i couldn't see anything. It was too scary to even tell anyone what was going on. I didn't know if I would ever be able to work or study or drive again. To this day I don't know why the optometrist could not diagnose something so simple as a cataract (i have since changed to a new practice), but the opthalmologist diagnosed the problem in less than a minute. And assured me it could be easily fixed and was nothing to worry about.

So next came the operation. I was so scared of moving during the op (how do you know FOR SURE that you will not flinch hen someone comes at your eye with a sharp implement or laser???????) that i was given so much happy juice that it was like I was drunk. And drunk people can't stay still or follow instrutions, so I moved during the op. I only found this out 6 wks later on the day of the op on the 2nd eye when the surgeon bluntly asked me 'if i intended to move this time'? Seriously, WTF??? I tell you what, when i found out what happended, i nearly chickened out of the op and left the hospital altogether I was so distressed. But after a very long discussion with the anaethetist, he convinced me to go in with no happy juice at all and that i would literally be paralysed with fear. He was right. So i was fully aware of everything that was going on during the op.

My left eye (the first one that was operated on) has some kind of scar tissue from the op, that gives cataract like symptoms in terms of glare sensitivity etc. I have always assumed this was due to me moving during the op. Because my right eye is fine, together they can see fine, and the glare is not much of an issue.

I am still very traumatised by the whole saga, from suddenly developing cataracts, to having scary surgery, to negotiating my way thru the world of optometrsists and opticians and glasses. I honestly do not understand the people on this site who do this shit for fun (!!!!!!) but good luck with it all if it makes you happy.


Cactus Jack 12 Sep 2012, 10:48


True, and I agree they were anything but inexpensive. I should have used a different word, but I could not think of one that REALLY expressed what I was thinking, in polite company. I don't know what Rodenstock, Zeiss, or Varilux progressives go for in Australia, but I suspect those are not what was delivered. Unfortunately, some ECPs fall into the same ethical group as undertakers.


SZ6 12 Sep 2012, 10:40

Thanks gwgs! I'll take that as a compliment!

They are from I've been pretty happy with them so far.

My PD is 64.5 - not sure whether this is big or small...

gwgs 12 Sep 2012, 10:35

SZ6 - What a pair of glasses you have there. WOW!

Where did you get them made, and what's your PD - I know this can have an influence on lens thickness.

Julian 12 Sep 2012, 10:33

Cactus: Newly Blind said that the optician 'just took my $800 and that was it'. I don't call that inexpensive progressives - unless they were Guyana dollars!

Cactus Jack 12 Sep 2012, 09:48

Newly Blind,

I don’t believe I have welcomed you to the group. For that oversight, I apologize. I think you will find understanding friends here. I would like to suggest that “Newly Blind” is, unless there is something else you have not mentioned, not accurate. If you had vision problems that required cataract surgery, you are now, more likely, “Newly Sighted”.

Based on your Rx, I am pretty sure your IOLs are not multi-focals. In many ways, that is good. You have not mentioned your field(s) of interest, but super sharp vision is usually handy in almost any endeavor. What you probably need is trifocals, let me explain why.

Single vision distance IOLs that provide as near 0.00 Rx as possible after surgery actually provide the very best visual acuity, but at the expense of limiting your ability to focus at intermediate distances or near. Your ability to accommodate and focus departed with your crystalline lenses. That means, you need some external help to focus clearly at those distances.

On the surface, progressives would appear to be the ideal solution and there are some high end progressives (read pricey) that may offer that for you. However, the progressives you are trying to wear probably do not fall into that category. Primarily, the only thing they offer is that they are "no-line" and that is the rub unless vanity is involved in your choice of eyewear.

From an optical design point of view, your glasses are overall R plano, -0.25, 180 and L +0.25 for distance with likely a somewhat circular area at the bottom center that provides a +2.50 add for reading. The neat thing about progressives is that there is no abrupt transition (a line) from the distance Rx to the reading area, which makes it hard for the inexperienced to detect that you are wearing multi-focal lenses. There are several transition areas. The most prominent is the central vertical corridor that makes a gradual transition from distance to the full add over a distance of about 5 mm. In theory, that provides a gradually increasing add which provides the ability to focus at different distances by simply tilting your head. At each side of the corridor is a very narrow transition zone (maybe 1 mm or less) where the Rx has to go from the add at that point to the distance Rx. All that sounds wonderful, until you try to apply it in practice.

First of all, in inexpensive progressives, the corridor is narrow and it requires careful glasses making and fitting to get it right for each patient. Frankly, these types of progressives are not suitable for everyone.

In going from distance to +2.50 for reading, the corridor is short which means that you have to become very skilled at hitting the exact tilt for the distance you need to focus and both eyes have to hit the same or nearly the same focus simultaneously.

What is happening to you is that the corridor and transitions are really too short and narrow for your needs and skill level. Most people start wearing progressives with +1.00 or +1.50 adds which makes the learning curve much easier. With the cataract surgery, your need for a significant add happened suddenly.

You mentioned your age and I believe you said you were a student. That means you do a lot of work on the computer and also read a lot. I think you might find trifocals very useful and comfortable. Trifocals in effect have 3 large "windows" with fixed focus over a relatively large distance. The distance segment is the whole lens with two exceptions. The intermediate segment is usually about 28 m or 35 mm wide and about 7 mm tall. It provides an add of usually 1/2 the reading add, but there are different power available. The reading segment is pretty much the same width as the intermediate segment, but generally extends to the bottom of the lens. If you do a lot of reading, as I do, you may find a pair of single vision Rx reading glasses very useful.

Everyone's situation is different and there may be other factors I have not considered.

Please feel free to ask more questions and contribute when and where you feel comfortable. I am sure the members would appreciate your experiences visual experiences prior to cataract surgery if you are willing to share them. ES and exist for benefit of the members. Again WELCOME.


Cactus Jack 12 Sep 2012, 09:01

Newly Blind,

Been there and done that. I had cataract surgery about 11 years ago and the idea of someone getting very sharp instruments near my eyes was, as you said, terrifying. I was awake also, and I think they gave me some "happy juice" in the IV. As you may have noticed, I am technically inclined and the doctor was very willing to explain the procedure. While I watched from the inside, I asked him to explain what he was doing and he did. When I went back the next day so he could check the results, one of the questions I asked was: " When can we do the other eye". Two weeks! That eye was a breeze because I understood what was happening and that the doctor knew what he was doing. I am pretty sure they gave me more "happy juice" as part of the procedure, and again the doctor narrated the procedure. The doctor had suggested that the IOLs be selected to give me mono vision and I agreed. Mono vision is where the strong plus power of the IOLs are selected to give near 0.00 for distance in one eye and mildly nearsighted (about -1.50) for reading in the other. For really good vision with both eyes, I still need glasses. I can function handily without them if I need to, but I usually only do that if I get up at night. Unfortunately, that option has to be chosen before the surgery.

Because you are new to ES and just so you will know, I am not an Eye Care Professional (ECP). I am a 75 YO semi-retired electronics and computer design engineer. I live in Houston, Texas. I learned what I know about optics and vision by study and solving my own somewhat unusual vision problems, when I got tired of unsatisfying answers from ECPs. Sometimes it is very hard to find an ECP who will LISTEN and take the time to explain exactly what is happening. Over the years, I have done a lot of technical instruction and have earned a reputation of being a pretty good explainer of high tech subjects. Some members of ES give me more credit for knowledge than I deserve, but I am happy to help you understand what is going on. I am an "Amateur" in the original French sense of one who does something for love rather than money. Not that I am opposed to money, I just have not figured out how - yet.

Even though you have not asked me to, I have written an explanation that you might find useful. I will post is soon on this thread.


SZ6 12 Sep 2012, 08:59

GOCer, ask and ye shall receive:

Newly Blind 12 Sep 2012, 08:17

no, Astra, nothing like that - just blurriness.

Astra 11 Sep 2012, 23:34

expensive thin one ... "thin lenses" regardless of price, would cause more chromatic aberration. Do you notice blue/red colored showing up when you look at daily life objects, such as around your home, or look at the surroundings of your neighborhood ?

Newly Blind 11 Sep 2012, 23:27

no idea of the brand of lens - an expensive thin one is all i know

Newly Blind 11 Sep 2012, 23:25

Mid twenties from Australia

I would appreciate your opinion Cactus Jack.You seem to know what you are talking about on this sight (ha ha sorry site)!

I would not call the surgery 'a non event' BTW - it is absolutely bloody terrifying to have someone rip out the lens of your eye while you are awake!!!!!!!!!!!!!


Cactus Jack 11 Sep 2012, 23:22

Newly Blind,

One more question. Do you happen to know what brand of progressive lenses you got?

Also, we are pretty much on a first name basis here, do Cactus is fine. If you would prefer to discuss any of this privately, my email is


Cactus Jack 11 Sep 2012, 23:18

Newly Blind,

Cataracts can occur at any age and there is no way that we know of to cause or prevent their occurrence. It is rare, but occasionally, babies are born with cataracts. The amazing thing is that cataract surgery today is almost a non-event and with IOLs near perfect correction is possible. 50 years ago, cataract surgery was a major surgical event that required months for recovery and very high plus lenticular glasses. I had cataract surgery 11 years ago and was able to drive myself to the doctors office the next day for a post op check.

I have an explanation of what is going on with the progressives and a few suggestions if you are interested.

May I ask your age and where you live?


Newly Blind 11 Sep 2012, 19:17

Hi Mr Jack!

OK so I am very young to have had cataracts- still of student age. I was frustrated having to take reading glasses on and off during lectures to see my notes and see the board. Also, I can't see to read anything without specs, so i would have to put them on to read my watch, or read my phone, or check the price of something at th shops. And lots of multitasking computer/reading or reading/tv etc. The optician thought it was a good idea, and never mentioned any weird or adverse effects from progressives. Just took my $800 and that was it.


Cactus Jack 11 Sep 2012, 16:01

Newly Blind,

I was pretty sure your new glasses were progressives. They are your problem. Could you tell me a bit more about yourself and why you chose progressives?


GOCer 11 Sep 2012, 14:51

14mm is pretty thick for modern standards. Post up some pictures, SZ6, and let's see them!

SZ6 11 Sep 2012, 12:00

30calcat - they are amazingly thick for 1.5 index and -10! What is the eyesize of the lenses?

My glasses are -10.75 with -1 astigmatism. In a 54 eyesize and 1.5 index lenses, they are about 14mm thick.

I'm not sure if it's possible to get the lenses much thicker in frames that don't look too big on me...

30calcat 10 Sep 2012, 22:03

SZ6 - those lenses correct my natural myopia - a mere -10 :)

Newly Blind 10 Sep 2012, 18:14

Hi Cactus

They are progressives (ie they don't have the line)


Cactus Jack 10 Sep 2012, 11:52

Newly blind,

Are the glasses progressives or standard bifocals?


Newly blind 10 Sep 2012, 07:25

Hi peep-le (get it?? ha ha)

I picked up my new glasses today, 6 mths post cataract surgery and all is not well:

R plano, -0.25, 180, add +2.50

L +0.25, add +2.50

I know i don't really need glasses for distance, but was sick of taking reading specs on and off all day so opted for multifocals.

Why is 90% of the computer screen blurry? I can see a couple of words in focus but everything left, right, up and down is blurry. The same when i am reading a book, i have to keep moving the book every second word to get it in focus.

Is this normal? Is this how multi-focals were 'designed' to 'work'? Or is my prescription wrong?

HELP!!!! Thanks.

sam12744 09 Sep 2012, 09:52


If you look at optical4less' website, there is info on 'special making' here:

I haven't bought from them recently, but see no reason why they wouldn't still do it, as its on their current website. I suggest you visit the page and then create a 'ticket' from there. If they don't understand you, its because they are Hong Kong Chinese. I suggest you ask them to refer it to Albert, who is, I think, the owner and a keen 'OO'.

Stingray 07 Sep 2012, 18:24

Try: Write to Monica Wu she may be able to accomodate you with thick lenses .

GOCer 07 Sep 2012, 13:29

I haven't had any luck getting anything over 15mm even with powers up to -20. Seems like lens blanks now stop at 15, and I get a myodisc-like ring around the rest of the lens area. I special ordered from optical4less years ago too and both came back 15-16mm - they said they were unable to make them any thicker. I do have an amazing pair of 18mm thick -10 glasses that were gifted to me a long time ago. They appear to have been from a different era in lens technology - perhaps they have cut down on lens blank size over the years.

I wonder if a clever optician can fuse 2 lens blanks together - I suppose it would have to be crown glass...

SZ6 07 Sep 2012, 12:21


Yeah, I contacted O4L about this a couple months ago and it seems that they don't offer extra-thick lenses anymore. I'm not sure if something got lost in translation between me and their customer support department (I think they are overseas and speak English as a second language)... but it sounded liek they do not offer this service anymore.

Have you ordered extra-thick lenses from them recently? I'd love to be proven wrong!

sam12744 06 Sep 2012, 17:28

SZ6, and go to 'Special making' as they call it. They will do some ridiculously thick/low index lenses, if you ask.

SZ6 06 Sep 2012, 08:13

Hi 30calcat,

Are those glasses for GOC, or are they your actual prescription?

It looks like if I want extra-thick lenses (18mm or more), I'm going to have to go to a brick-and-mortar optician. But my actual prescription, a "mere" -10 and change, will only max out around 13 or 14mm thick even with CR39 and large-ish frames. I imagine the lenses will need to be -13, -14, or stronger if I want lenses over 18mm.

Any thoughts as to the best/easiest/most cost-effective way to do this, Eyesceners?

Astra 06 Sep 2012, 02:37

Re Gwendy

"Guys, I need your help in understanding why you find thick glasses so attractive on a girl. I don't get it. I always thought that thin lenses were nicer than thick ones, but now I know there are lots of guys who think differently. What is it about thick edges, power rings, cut-in cheeks, small everything and big reflections that is so wonderful? Help!!!"

For me it is so important.

Why wearing a thin lenses look like a window pane ?

as though there is nothing special about your eyesight.

you know being myopic means you can't see very well at distance. Why not let people know you are myopic

30calcat 05 Sep 2012, 23:14

I purchased the frames online but have also had no luck with lenses with online retailers - they seem to max out at 12mm thickness and don't do Trivex or 1.5 index lenses. So I had my optometrist office send the frames out for new lenses like anyone would. I assume it went to one of VSP's labs as they covered one of the lens replacements. I suppose the Internet has been great in providing frame selection far beyond what most optical shops can stock, but it can be a bit of a gamble when it comes to lenses.

SZ6 05 Sep 2012, 12:51


Where did you get those fantastic glasses? And how thick are the lens edges? It looks like they are approaching a full inch thick. I have never been able to find an online retailer who can accommodate such thick lenses - can you share your secret?

GOCer 05 Sep 2012, 11:59

Gwendy - both you and your friend are right, really. If you look at at a lens, it is made of two curves, one in the front, one in the back. A minus lens has two curves that curve away from each other as you get to the edge of the lens. The steepness of the separation between the two curves determines the lens power, like your friend says. Because of this, as you have observed, the steeper the curve difference, the thicker the lens is at the edge.

I think Crystal Veil makes a very solid point. People select and wear styles of jewelry and glasses frames to enhance the way they look. The lenses in the glasses do the same thing! A thin pair of lenses is just like a window pane - boring. Lenses that bend light with steep curves and internal reflections are more interesting to look at.

In a given day you may see a variety of lens powers cut and set in all different shapes of glasses frames. In the higher lens power, each is a unique gem! I especially like the glasses 30calcat posted pictures of - the semirimless frame exposes more of the lenses, showcasing all the interesting things to look at in a pair of thick lenses!

Melyssa 04 Sep 2012, 06:44


The answers are yes and no, respectively.

In the 20 years I wore glasses before discovering drop-temples, which made me enjoy wearing glasses enough to have over 40 pairs of big, bold, and beautiful plastic frames in different styles and colors now, I did have polycarbonate lenses and high-index lenses, when having just one pair of glasses. Now the cost of putting in high-index lenses in all of my frames would be affordable only by movie stars, sports personalities, lottery winners, and politicians (and/or their corporate sponsors).

REd 03 Sep 2012, 13:19


Have you ever had polycarbonate lenses? They have excellent resistance against shattering but are not great in optics-light splits as in a rainbow.

Are you using high index now?

Melyssa 03 Sep 2012, 11:17


I remember glass lenses, having had them for 8 years, but my parents made sure that my lenses were shatter-proof in every pair of glasses I had. At least my prescription then wasn't the -9.00 it is now, otherwise they would have been mighty heavy. I've had CR39's since just about the time they came in.

REd 03 Sep 2012, 11:12


This may help you on lens thickness. Before 1972 lenses were made of brittle crown glass. Lenses shattered easily, believe, I experienced it. In the USA, the FDA established "shatter proof" standards. A plastic material, CR-39, passed the new standard, a steel ball was dropped on the lens. The thinnest part of a CR-39, if memory serves, is 1.8 mm's. For a nearsighted person such as you and me then thinnest part of the lens is directly in front of the pupil. For a farsighted person the thinnest part of the lens is the edge and it is thickest directly in front of the pupil.

For a nearsighted person the edges of the lens are thicker than the center. How much is a function of the wearers prescription and the refractive index (ability to bend light) of the lens material. CR-39 has a refractive index of ~1.50. If you want lenses with thinner edges consider an optical material with a higher index, say 1.74.

BTW the drop ball test is used only to qualify the material; it is not done on every lens.

Crystal Veil 02 Sep 2012, 14:48


the following is just the answer from one member of this community. For me it's always the combination of a confident lady and rather strong glasses. The lenses add an element of liveliness. If the frame of the glasses is well chosen, the eyes are the first to catch my attention. The balance between the eyes and the mouth is different. Often the lips seem enlarged. Of course this is an optical illusion but the effect can be surprising and in my view, charming. For me, glasses are the cherry on the cake. No more, no less. Opticians make a mistake by showing models with empty frames in the photos in their shop windows. They are only showing half the product that they are trying to sell. In my portrait photography I try to show that a lady in strong glasses can be very attractive indeed. I hope that this makes some sense to you. No doubt, reactions by other members will throw a more varied light on the matter. Thanks for asking!

myofan 02 Sep 2012, 14:42


I wish I knew why. I'm 65 years old and have felt this way about strong myopia glasses on girls since at least when I was about 8 years old. I've always felt a profound sadness when a beautiful bespectacled woman changes to contacts. Please don't!

Gwendy 02 Sep 2012, 08:58

Guys, I need your help in understanding why you find thick glasses so attractive on a girl. I don't get it. I always thought that thin lenses were nicer than thick ones, but now I know there are lots of guys who think differently. What is it about thick edges, power rings, cut-in cheeks, small everything and big reflections that is so wonderful? Help!!!

Melyssa 01 Sep 2012, 09:52


From my experiences, as my RX went from a humbled beginning of -1.75/-1.50 to its present -9.00, the lenses became thicker. I use only CR39's. And of course, the curve has just about straightened out. But with my 40+ pairs of glasses, the larger the frame, the thicker the lenses, more towards the outer edge because of my myopia.

Newly Blind 01 Sep 2012, 05:57

Thanks Soundmapt

There are still some other issues with my prescription so I don't think over the counter specs would work although I still think i was ripped off


Gwendy 31 Aug 2012, 16:54

I hope I'm not being a pest by posting too much. My friend ane me are having a little disagreement. A little background: I'm nearsighted and every year my prescription gets a little stronger. And I have noticed that as the numbers get higher the lens gets thicker, at the edge. At least since it was -6. Now it's -10. So I argued that the way they make a lens stronger is to make it thicker. My friend says it's only a coincidence. She says the extra strength comes from how they curve the front and back of the lens and from other things they do. Who is right? A little explanation would be welcomed. Thanks!

Soundmanpt 31 Aug 2012, 15:19

Newly Blind

Well I don't think your prescription is so bad as to where you will have any trouble seeing fine with your new thinner lens glasses. To be honest i am not sure that it was that necessary even. But now i can make you feel even worse. Your eyes are only +.25 different, I think you would be fine with over the counter readers as long as you don't have any astigmatism issues to deal with. You could go either way meaning you may be fine with a pair of +2.50 glasses or maybe a pair of the +2.75 glasses.

Also the other option is some of the on-line retailers where you can find many glasses in your correct prescription for anywhere from $7.00 to maybe $25.00. Check out "" or some of the others.

Mr Cockeyed 31 Aug 2012, 08:45


Who in their right mind with a rx like the first two examples would wear a banded rimless frame?? I don't think with such thickness a wearer should use a frame like the one illustrated.

Cactus Jack, I think for low rx's and especially full rimless frames it looks good, but sometimes the reflection is mind bending I agree with you an ar coat is beneficial

 31 Aug 2012, 08:28

Hi People

My prescription for reading is +2.75 and +2.5 and my optometrist has just sold me really expensive fancy lenses that are apparently 'thinner and more attractive'. But I have been doing some googling and it seems that these lenses actually result in less clear vision. Is this correct? If so why would the optometrist sell me glasses that don't help me see at an optimum level, and why would he not explain any of this to me? Is this standard practice?

Thanks for your advice

Newly Blind

Cactus Jack 23 Aug 2012, 11:33


Edge polish should not make any difference in the apparent thickness of a lens. However, it could affect the appearance of the "power rings". Power rings are internal reflections of the edge of the lens caused by the prism effects of a minus lens. Lenses are actually an infinite number of thin prisms arranged in a circle. In a minus lens, the apex of the prism is at the center and the base of the prism is at the edge.

You can test this explanation about the internal reflection of the edge by placing your finger on the edge of the lens (you may need to wet your finger for best contact) and note the change in appearance of the power ring in that area. Generally, power rings are slightly less obvious with polished edges that with frosted edges, but that is because the frosted edges often look white.

I have often thought that an AR coating on lenses with polished edges might help as long as the AR coating also covered the edges. Also, I have thought a black coating on a frosted edge might be helpful in minimizing the obviousness of power rings in a high minus lens, but I have not tried any of these.


30calcat 23 Aug 2012, 09:49

Do polished edges really make thick lenses look thinner?

Opticians often charge extra for this service, but does it work? I happened to get one of each in the same frame, so I took some side-by-side photos for comparison:

To be fair, the polished pair is 8% thinner due to the Trivex lenses. But both seem to have the same severity of power rings and thickness. The polish doesn't seem to hide the lens thickness or strength, but just makes them look "better" in the same way that a clear light bulb looks "better" than a soft white one?

Tell me what you think!

Jarred 13 Aug 2012, 16:42

Roy, Your story is almost identical to mine. I had 9 base out prism and needed multifocals. With all that prism I don't think you will be able to get varifocals, Zeiss were the ones that offered varifocals with high prism but I think even they stopped at around 6 base out.

I have tried a number of varifocals from the cheap varieties to nearly £700 worth of expensive customised designs. Personally I have found all of them to be useless. They do not offer a wide view at any distance. I found varifocals to be unworkable as a heavy computer user.

IMHO The absolute best option are trifocals! They are great for driving and you can use the computer without having to scan around the screen using your neck instead of moving your eyes.

If you are in a similar situation to what I was, surgery may or may not have been suggested. I had very sucessful surgery this year and I would recomend that it is worth invesitigating. I found YouTube was a good source of information from real people that had undergone the surgery. It is a pretty surreal experience, I had a total of 26 base out of correction surgically corrected. My prescription now has no prism in it at all, although I have been warned that as prism progression can continue, in another 10 - 15 years I may be going back for more surgery. I would gladly have the surgery again than be trying to find glasses with 26 base out of prism left and right!

Roy 13 Aug 2012, 11:39

I have just had an eye test and am looking for some new varifocal glasses with a large intermediate area. Essilor make some but they can't handle my 9 base-out prism (in both lenses). Does anyone know a supplier of glasses with a large intermediate area for computer use, and including a small distance area at the top and a reading area at the bottom?

sam12744 10 Aug 2012, 08:03


I think they call it 'special making'.

Muggy 09 Aug 2012, 20:30


Thanks for that. I'll check it out.

sam12744 09 Aug 2012, 08:22


Optical4less love doing ultra-low index lenses to give very thick lenses, even with 'low' prescriptions. You need to ask them for a 'special order' though. They have examples on their website.

Muggy 09 Aug 2012, 02:43

Thanks anyway, Likelenses.

Likelenses 09 Aug 2012, 00:33


I am not aware of any online optical company that does special order ultra thick glasses.

A few years ago I inquired of SGS,who advertizes on this site. He really did not seem interested in providing this service,but only likes to peddle his standard fare junk.

I have mine made up by a local optician that does not even have a web site.

GOCer 08 Aug 2012, 17:47

Power Rings are actually a technical term!

"The thick edges of high minus lenses produce internal reflections, known as power rings, which are visible to others and exacerbate the apparent thickness of the lens."

 08 Aug 2012, 17:26

Power rings? LOL. Do you think she is The Mandarin from Marvel Comics or something?? hahahahaha

Kyla 08 Aug 2012, 12:34

Phillip, The vision has been great with the glasses, my eyes feel much more relaxed in front of the computer today at work.

gwgs 08 Aug 2012, 11:16

30calcat 06 Aug 2012, 12:13 - You certainly can take it as a compliment. They are a beauty I would like to behold!

I'm going the opposite direction from everyone even the power-rings /cut in is telling me different things.

I'm guessing they're somewhere between -17 and -20.5

Let us know!

30calcat 08 Aug 2012, 10:56

Thanks myofan, Likelenses, and Trent for the feedback! I didn't special order my lenses - they were shipped off to be done at a big lab like most people's lenses nowadays. But even so, it seems the consensus so far here is that they are uniquely thick, though not as thick as Likelenses' binoculars.

So far we have one guess for -5 and another for -12. Quite a big range to start out with...

Philip 08 Aug 2012, 10:55

Kyla, You have done well. After seeing you in glasses for a few days no-one will remember you when we didn't wear them. How's the vision?

Kyla 08 Aug 2012, 07:38

Rachel, Since I just got them yesterday, I haven't had too many comments yet. A couple people at work yesterday said my glasses looked nice, but I really haven't seen too many family or friends yet.

Rachel 08 Aug 2012, 01:29

Kyla - how are you coping with being a full-time glasses wearer having not worn them for the best part of two decades? Do you feel self-conscious at all? And what's the reaction of your friends/family been like?

Muggy 08 Aug 2012, 00:46


Where can you get 'special order thick lenses' from? Is there an online retailer who supplies them?

Likelenses 08 Aug 2012, 00:32


The reason that they are so thick is because that is what I wanted.

Anything can be done with lenses,if the optician is a creative thinker.

When I was at -4.25 I had a pair of myodiscs crafted.They were quite cool.

Yes over the years there have been a lot of stares,and questions,but that is the object.

Kyla 07 Aug 2012, 19:02

Hi, I'm 34, I've had glasses/contacts since I was 13..Started needing glasses to see far away in junior high and gradually started needing glasses all the time, got contacts in high school and have generally worn contacts over the years. As of late I've started getting a lot of eye strain at the computer, I got worried I might need bifocals already. I went for the eye test last week and even though I couldn't see the bottom line clear on the near vision test, he said my main problem was my eyes not working as a team, I think he said i have exoforia if that makes sense and could benefit from a prism correction in my glasses. He said generally this doesn't develop in adults but he has seen cases like mine. My prescription is OD -4.50 2.5 BI OS -5.25 x -0.25 x 90 2.5 BI

He said he couldn't give me a contacts prescription because they don't make contacts with prisms. I wore my contacts this morning and got a call my glasses were in and picked them up during lunch. When I put them on, I saw a bit of a fish bowl effect and my eyes felt like they were pulling out some, but the optician said it might take a while to get used to the new glasses. I wore them the rest of the day and they actually feel pretty good now. I did take them off and put on my old glasses for comparison and the whole computer screen looked blurry and I felt like I was seeing double, much worse than before the new glasses. I assume its my eyes just getting used to the glasses. The doc scheduled me to come back in February for a recheck in 6 months, he wants to see how I am faring with the prisms. He said a bifocal add and possible adjustment in the prisms might be needed. I guess I'm going to have to adjust to wearing glasses now. I've never really worn them full time so we'll see how that goes. I notice the inside of my glasses is thicker now, I assume that is the prism. I'll let you know how it goes, if anyone has any advice let me know. Thanks Kyla.

John S 07 Aug 2012, 07:21


I don't know if the UV protection would have any effect on the lenses turning yellow. I think it is always a good idea to have UV protection.

30calcat 07 Aug 2012, 06:59

Likelenses - wow 1.5 inches, why are your glasses so thick? I have never seen glasses even close to that thick before. How often do you wear them? Do you ever get questions or stares from strangers about your eyes or glasses?

Roy 07 Aug 2012, 06:10

Thanks to all for your comments on my yellowing lenses. They confirmed what I thought that the effect seems to be permanent. The glasses are quite wearable and the yellowing really only notices when comparing them to the pair kept most of the time in the dark, so UV looks like the cause of vthe problem.

John S - your comments about ABBE value are interesting. Because of the high prism in my glasses I do usually go for higher refractive index lenses. I checked further into the lenses in the yellowing glasses and they are actually 1.74 index plastic so I guess they have very poor ABBE values. I will go for lower indices in the future.

Some online retailers offer a UV protective coating to protect the eyes from UV. Would this also protect the lenses and so stop the yellowing?

Likelenses 06 Aug 2012, 23:09


I have to agree with myofan that they are not as strong as one may think.

When I was at -3,00, I began wearing special order thick glasses. My first pair of -3.00 were 3/4 of an inch thick.

As my prescription increased I continued to get special order thick lenses.

I now wear -9.00,that are a bit thicker than 1 1/2 inches.

Trent 06 Aug 2012, 21:48


My guess is -12d

Trent 06 Aug 2012, 21:47


My guess is -12d

myofan 06 Aug 2012, 12:20

30calcat -- Handsome as these glasses undoubtedly are, they don't really look very powerful! They look to have a convex front, meaning that they're likely below -9, and the arms of the glasses -- admittedly very close to the lenses, but all we have to go by -- aren't minimized very much.

I'm gonna guess maybe -5 but VERY THICK.

30calcat 06 Aug 2012, 12:13

gwgs - I take that as a compliment, especially from around here.

That said, before I divulge the actual prescription, I'm curious to see what power all the glasses fetishists here think my new lenses are.

I'm basically curious how out of the ordinary I'm being by wearing these. If you saw someone wearing these, would you take a second glance? Or is this weak sauce, a fairly common prescription you see people wearing all the time. Feel free to be honest - I like the glasses so much that I'll probably keep wearing them no matter what you say.

Melyssa 06 Aug 2012, 07:06


Thank you for the explanation. I don't recall that summer being hot, especially when Hurricane Belle struck the region, so it must have been the olive oil from my spaghetti with oil and garlic creation. :)

gwgs 06 Aug 2012, 03:16

Wowza, they are thick!!

What's your prescription?

30calcat 05 Aug 2012, 15:15

Got new lenses this week, and thought I'd share the experience and pictures as I think other higher script wearers would find this interesting:

I've tried a lot of different plastic lenses over the years and haven't been happy - polycarb and hi index lenses have too much chromic abberation, and all CR39s now are mid-index 1.56 which are heavy, and have way more distortion than the low-index 1.5 lenses that no one seems to make anymore.

So I decided to give Trivex a try, and had my favorite frames re-lensed. It turns out to be the answer to all my problems. It's quite amazing to be able to look through any part of the lens and see 20/20 with both eyes. With other lenses, the distortion often created a double-image if I look off the center of the lens, and every new pair of lenses involved an exercise of relearning which image to ignore when looking around, or just not look around at all and move my neck instead.

Pictures can't demonstrate the improvement to you, but I know you all like pictures of strong lenses so here's how they look:

JP 05 Aug 2012, 11:11

Melyssa - That green stuff results from oxidisation, so it's where the metal reacts with oil/sweat from your skin.

Melyssa 05 Aug 2012, 09:26

In the 1970s, when I had metal frames, the last pair had a problem with the lenses becoming bright green close to the frame. One trip to the optician's took care of that problem, although I cannot recall what caused it or how it was fixed permanently. Either way, after my next eye exam (the following year), I switched to plastic frames and never had any "colorful" problems with lenses again.

Cactus Jack 04 Aug 2012, 17:36


The yellowing may be caused by premature aging of the lens material. The yellowing effect may be some molecular changes in the plastic polymer used to make the lenses or it may be similar to the process used to tint plastic lenses where the lenses are placed in a dye solution that penetrates deep into the lens. If it is the later, you may be able to have them bleached out. However, I would not count on it very much. The thing to remember is that the yellowing is probably not a surface effect and probably can not be "cleaned". The yellowing process could be similar to the yellowing you occasionally see in older cars with plastic headlight covers which is supposedly caused by UV exposure.

Please let us know if you have any success. I have a pair of low index (about 1.50) glasses that are 7-8 years old that have developed a decidedly yellow tint and some much older glasses that are still crystal clear.

John S 04 Aug 2012, 17:24


There is nothing you can do about the yellowing. The reason the lenses are turning yellow is because of UV light. You must keep your other pair out of the sunlight or fluorescent lighting, or they would have done the same thing.

Most plastics are affected by UV damage. That is why it is important to wear UV protection. It can cause cataracts and yellowing of the lens.

A good thing about glass - It naturally stops the UV rays, and always stays clear. It is very hard to scratch, but can easily shatter. It also has the highest ABBE value, which equates to the best vision.

Some of the lowest ABBE values are the very expensive hi-index and also poly lenses. The rule is, the higher the index, the lower the ABBE value.

I found this listing of lens types:

It is somewhat out of date...But as you can see, CR-39 & std. glass are the best. Poly is the pits.

Index ABBE Value

Crown Glass 1.52 59

High Index Glass 1.60 42

High Index Glass 1.70 39

Plastic CR-39 1.49 58

Mid Index Plastic 1.54 47

Mid Index Plastic 1.56 36

High Index Plastic 1.60 36

High Index Plastic 1.66 32

Trivex 1.53 43

Polycarbonate 1.58 30

 04 Aug 2012, 16:59

Sounds like you are justifying an anime fetish, G.

Soundmanpt 04 Aug 2012, 15:23


Unless you purchased them on line, I would suggest taking them back to where you purchased them and ask them to clean them, if possible. They ahould have other cleaners that might fix the problem.

Roy 04 Aug 2012, 03:51

Can anyone help with this lens query? I bought two pairs of glasses around a year ago. One pair is a spare and have hardly been worn. I noticed that the lenses on the pair I wear are really "yellowing" on the edges. (They still look clear when looking through the faces.)I have tried all sorts of cleaners on them with no effect. The rarely worn pair (which have been kept in a case)look as new. Both pairs are made of 1.67 index plastic and have no coatings. (I especially asked for this.) Is there any way of preventing this discolouration?

G 18 Jul 2012, 07:14

I believe I have a solution to this problem (the difference between plus and minus): we are programed to notice large eyes, because they express feelings (surprise, astonishment), so they draw our attention and become emphasized in our perception, this does not happen when the eyes are minified, because we attach no meaning to eyes becoming smaller.

My experience has taught me that plus lenses usually seem twice as strong as minus lenses do (a +6 will look as strong as a -12), and I think now that this is a subjective difference, stemming from our automatic "reading" of facial expressions.

gwgs 18 Jul 2012, 07:00

Exactly what I was thinking; the magnification from the front, and rear (to onlookers, and inlookers) seems far greater for plussies, than short sighted glasses.

varifocals 18 Jul 2012, 06:24


I think it is because of the magnification plus lens give.

My wife sayes my glasses are thick & strong yet she is an almost opposite minus.

gwgs 18 Jul 2012, 03:15

I have often wondered that too! With a plus prescription I can never seem to guess how dependent the wearer is on their glasses, and what sort of prescription it is. E.G. +3 looks so much stronger than it's opposite number.

Asdoo 18 Jul 2012, 00:51

Why do plus lenses seem stronger than minus lenses that are the same power i.e. +5 seems stronger than -5.

RL 02 Jul 2012, 21:07

Cactus Jack, The lenses are Optima mid-index 1.60, and I do agree that the slightly larger image size is probably related to having a lesser curve on the back of the lens.

Cactus Jack 02 Jul 2012, 20:33


You get the prize, that one has me stumped. The only thing I can think of is that minification is caused primarily by vertex distance effects and vertex distance is measured from the front surface of one lens to the rear surface of the next lens. It is possible that vertex distance effects may be related to the curvature of the back surface of your glasses. IF that is the case (and I am not sure it is) the biconcave lenses would have a lower Rx in the rear surface than the plano front lenses.

All this is a SWAG. I have been rather suspicious for a long time that the formulas used for calculating vertex distance effects are too simplistic where high Rx lenses are involved. You have raised a very interesting question. I won't promise to answer it, but I plan to think about it and do a little more research.

One question, what is the lens material in the two pairs of glasses. I wonder if abbe values could be playing a role.


RL 02 Jul 2012, 17:18

Question for Cactus Jack. I've been talking about the virtues of plano vs. biconcave lenses and I find that i get a better image with my biconcave lenses. The reason seems to be that the image size is slightly bigger than with the plano fronts. Of course you need to keep your sightline pretty well in the middle of the biconcaves but this is the case with most high minus prescriptions. I wondered if you had any thoughts on why the minification seems less with the biconcaves. My Rx is R -12.00 and L -15.00. The biconcave lenses have -2.00 base curves.

Asdoo 21 Jun 2012, 02:42

Cactus Jack

How did you know I was just bored?

Cactus Jack 19 Jun 2012, 21:08


Thank you for being honest. I thought as much, which is why I wrote the 2nd paragraph. Study and leaning can be an extremely effective cure for super boredom. Try it, you may be surprised.


Cactus Jack 19 Jun 2012, 20:52


Single vision readers or even bifocal readers are quite reasonable for a person with your Rx or any Rx for that matter. You are not the only person who needs specialized glasses for unusual functionality. There is even such a thing as quadrifocals. They are essentially trifocals with another close segment with the flat top at the bottom, at the top of the lens. They are great for people such as electricians who need to see close things clearly that are over their head. It avoids cricks in the neck to try to get the appropriate segment into position to see their work.

If you can give me the working distances involved I can suggest an Rx or you can figure it yourself by using the formula: Lens power = 100/working distance in cm or 39.37/working distance in inches.

In determining the actual Rx of the glasses, remember that your distance Rx corrects your distance vision to 0.00 and you have to algebraically add the lens power above to your sphere Rx to get the absolute value of the Rx. Always copy the cylinder and axis to all new Rx without any changes.

For example, if your calculations indicate that you need a +1.50 add to focus at 66 cm or 26 inches, you would algebraically add the +1.50 to your -5.50 and the result would be -4.00. If you wanted bifocals with the -4.00 as the distance segment and a reading segment of 40 cm or 16 inches, that would be a +1.00 add to the above.

You would use a reduced PD for the "distance segment" of about 2-3 mm and 3-4 mm for the reading segment to help with required convergence.

If you want to run an Rx by us before ordering, please do so.


Guido 17 Jun 2012, 12:03

I am interested in having reading glasses made. I have a +2.75 add with about -5.5 to 6.00 D of nearsightedness. I have a current bifocal script and would like to order some reading glasses from an online retailer. The reason for readers is that I am nearsighted enough to be unable to see anything without aid, and often the bifocal segment is not where I need it. That said, I am not getting the "readers" purely for reading but for tasks where I might have to look up at something close (like working under a car or on a ladder). Is there a standard reduction of the pupillary distance that should be considered when ordering reading glasses? I did a quick measurement of the inside of the bifocal segment on one side and outside of the bifocal segemnt on the opposite side. I came up with about a 2mm reduction in P.D. assuming the optical center of the bifocal segment is in the center of the segment. Lastly, should I consider reducing the add by 0.25-0.50 as I am not using the readers for reading per se, but for tasks as described above where I might not be as close to the desired field of view?

Thanks for looking and if the questions or descriptions are unclear, please ask for said clarification.

Thanks for visiting.

Asdoo 16 Jun 2012, 13:56

I already knew all the answers to the questions I asked, including that girl's prescription. The only reason I posted those questions was because I was super bored.

nickweymouth 16 Jun 2012, 12:45

pmsl puffin

nickweymouth 16 Jun 2012, 12:44

Puffin 16 Jun 2012, 10:57

I think "Guess the Prescription" would make a great gameshow, a bit like "The Price is Right". All the female assistants could be GWGs. What a shame it is only fantasy.

Cactus Jack 16 Jun 2012, 07:24


Somewhere between +2 and +5. Maybe! Playing "Guess the Prescription" is about a productive as playing guess the number of beans in a jar and about as useful, unless there is a prize involved. There are just too many variables that can affect at the appearance of glasses just by looking at them. Plus or minus lenses, vertex distance from the eye, your distance or the camera's distance from the glasses, viewing angle, lens index of refraction, lens size, lighting, shadow, and actual Rx just to mention a few. If it was easy, Optical Professionals would not spend thousands of dollars on equipment to measure the Rx and spend significant time learning how to use it. About all you can tell from looking at glasses is: are the lenses plus or minus? is the Rx weak or strong? and are the lenses thick or thin? If you know how, you can make glasses look very strong, even if they have no Rx. For example, there are some "fake" high minus glasses sold in novelty stores that have no Rx. One of the female villains in "From Russia with Love" wore them.

You seem to be extremely interested in learning about optics, lenses, and how they work. This is a good place for a specific question, but not a good place to learn much about optical physics. I suggest starting in the school library and researching on line, there is lots of good information there. It also would not hurt to study math and physics in school, if they are offered. They form the foundation of the subject. Often, one's own vision and wanting to see as good as possible, fosters an interest in vision and optical sciences. It is not an easy subject, but often the most rewarding subjects take considerable effort to learn.


Asdoo 15 Jun 2012, 20:32

Can you tell from this picture?

Cactus Jack 15 Jun 2012, 18:48


More plus than you actually need has the same effect as being a little bit nearsighted. With a +2.50 distance sphere correction with the same cylinder and axis. You would be +0.25 and +0.50 over. Assuming you have 20/20 vision with your existing glasses, wearing a small amount of over correction would make everything beyond about 4 meters (17 feet) a bit blurry with one eye and blurry beyond 2 meters (6.5) with the other. In any given situation, your brain would select the clearest image and use that as the primary source and supplement that with visual information from the other eye.

Can't really hurt anything unless you need to see distant object and signs clearly.


Stingray 15 Jun 2012, 14:11

Cactus Jack: I need your opinion on this. I presently have a prescription of +2.25 -2.00 axis 100 / +2.00 -.75 axis 085 add +2.50

My present glasses are progressive lenses. My question. Could I wear glasses with single vision lenses with a sphere of +2.50 with the same cylinder correction? Would I be able to see okay out of them? Thanks

Cactus Jack 15 Jun 2012, 07:51


It is impossible to tell very much about the Rx from the pictures. The swirly images you are seeing is an optical phenomenon associated with plus lenses that is not present in minus lenses. It is related to the vertex distance, which is the distance from the eye to the lens.

Plus lenses have an optical characteristic where within a certain relatively small vertex distance, they appear to magnify or enlarge images, with the image delivered to the eye "upright". As you increase the vertex distance, at some point, depending on the +power of the lens, there will be a "zone of confusion" where the image itself appears to become confused (swirly?) and beyond that distance, the image will appear inverted. The vertex distance where confusion occurs is related to the power of the lens. The more powerful the lens, the shorter the vertex distance to confusion.

Theoretically, you can estimate the lens power by measuring the distances, but that is best done on a precision optical "bench" using lenses with only sphere powers. Glasses often have both sphere and cylinder powers and that makes it very difficult to determine the Rx by measuring the distance to where the "zone of confusion" occurs. Also the "zone of confusion" is not a specific place, but a relatively large region where the confusion exists.

The inversion phenomenon is common and well known. The powerful + lenses in the eye invert the image projected on the retina, Powerful projection lenses invert images on film and project it upright - which is why you have to insert slides in a slide projector upside down.

Telescopes made in the early 1800s inverted the image delivered to the eye until telescope makers discovered that you could use another + lens to re-invert the image and deliver it with a normal orientation.

I would suggest you do some research on optics and optical phenomenon to find out more and develop understanding about how all this works. Much of what we know about optics was discovered and codified mathematically by Sir Isaac Newton around 1700. It is fascinating.


Asdoo 15 Jun 2012, 04:55


How strong do they look?

 15 Jun 2012, 04:37

plus lenses

Asdoo 15 Jun 2012, 03:37

You probably misunderstood what I said. When I say swirly I mean this.

 14 Jun 2012, 20:11

Too much alcohol.

Asdoo 14 Jun 2012, 19:55

What eye problems do people have when their lenses make things look "swirly"?

Clare 05 Jun 2012, 01:17

Hi Soundmapt - you're spot on with a couple of points: hers are slightly larger than mine which are fairly narrow (50 18 26 frame size) and I have 1.6 lenses with only -0.50 of cyl. I know she doesn't have much cyl I'm sure, or at least the doesn't wear toric contacts. I havent had chance to try them, as though we sometimes do talk about issues, like when she was told the had veins from over-wearing contacts, we haven't ever got to compare. I don't know many people who do!

Soundmanpt 03 Jun 2012, 09:32


There are several things that could enter into why your friends glasses appear to be stronger than yours when looking at them. For one the possible difference in size of frame, for example if your glasses areon the smallish side and her are a bit bigger and maybe more round hers would look to be stronger. Also you may have ordered a higher index lens package than she did? Also her glasses may contain more astigmatism correction than yours do.

Have you ever had a chance to try her glasses to see if they compare to yours?

minus 5 who luvs gwgs 03 Jun 2012, 01:25

a current gf is minus 16.25 in her worst eye her normal glasses are a sort of oval shape and do not look all that strong when you look straight at her There is of course quite a lot of cut in and power rings and of course flat fronts I bought her some trendy squarish ones the lenses look much thicker as they are slightly larger On the front page of eyescene go to the Russians pictures of myopic glasses by dioptre and you can see the difference of the same rx in different styles

Clare 03 Jun 2012, 00:45

Thanks Puffin. I think it's easy to identify glasses that aren't strong and those that are very strong, those in the middle can be deceptive - I was with with a friend who has a prescription almost identical to mine but hers looked stronger than I think mine do. Perhaps I'm not a good judge of that though!

Asdoo 03 Jun 2012, 00:45

Objects through a lens with astigmatism can also look swirly.

Puffin 01 Jun 2012, 18:57


There are a few things to look for to detect strong lenses. The most obvious thing is cut in (if myopia). The more there is, the stronger. If the lens size is smaller than the amount of cut in, it will be invisible, because it will be outside the lens.

The next most obvious thing is eyesize. This is harder to hide, but only becomes very apparent with quite a strong lens, either plus or minus.

After that, lens thickness, which can be hidden by choosing a lens material that does a lot of refraction for little increase in thickness (ie high index), or by choosing a plastic frame to hide it.

Astigmatism is harder to detect because it is often not very high (only a few dioptres), and can get disguised by eye size changes, but you are looking for eyes that look odd shapes. Be aware they might be odd shapes to start with, or be made up to look different. Or look though the lens if you can, and observe the effect on things through the lens, if they are slanted, astigmatism is there.

High strength myopia lenses are often flat or near-flat to help with thickness. Although these days, its possible that a lower-strength wearer might want to lose a little thickness from their lenses this way too.

Crystal Veil 01 Jun 2012, 16:42

Thank you, Cactus Jack!

Clare 01 Jun 2012, 16:24

A colleague has the trendy 'large' style frames that really suit her. She is -1.25 with -1 cyl but her glasses look really strong. Is that the lenses themselves or the size of the frame, or even the cyl?

Soundmanpt 31 May 2012, 15:53


More than likely they will suggest you get high index lenses when you go to order your glasses. That is mainly done because they charge extra for high index.

Melyssa 31 May 2012, 14:52


With my myriad of adorable eyewear, the larger the frames, the thicker the lenses, all of which are plastic frames with CR-39 lenses.

Sam 31 May 2012, 12:17

Thanks, that's interesting that larger frames make them look stronger I would have thought it would be the other way round. I also wondered if the thinner lenses look different in how they reflect the light and whether that made them appear stronger. I don't think any thickness will show as I will probably go for lastic frames. Will I be recommended to go for thinner lenses with this prescription do you think?

Revolver 31 May 2012, 10:52

Sam: couldn't tell from your post if you want them to look stronger or weaker. If you want them to look stronger, besides larger frames and a low index lens (1.50 is o.k. if that's all you can find but the original CR-39 was 1.47 and are still available) here's a couple more tips.

If you order them safety thickness they will of course be thicker, and then specify a plano base curve which is usually a hallmark of higher minuses.

That is, if you want them to look stronger and can find an optician to do it.

Cactus Jack 30 May 2012, 17:44

Crystal Veil,

Very close assuming a sphere only Rx.


Crystal Veil 30 May 2012, 17:09

Cactus Jack,

I read your formula for glasses Rx vs contact lenses Rx with interest. Am I right when assuming that a -7.00 contact lens prescription is roughly the equivalent of -7.75 glasses? I'm asking this question with a specific new model in mind, for a photo shoot later this year.

Soundmanpt 30 May 2012, 16:19

Sam if you want your glasses to be thicker then you want to order your lenses as 1.50 that should give them some thickness. Also if you get a bigger style frame your lenses will be thicker as well as your rx is for distance meaning your lenses will be thicker on the edges than they are in the center of your lenses.

Sam 30 May 2012, 16:05

I am going to buy new glasses soon. They will be -2.50 and -2.75. Can someone tell me if there is a difference in how strong they look depending on whether they are standard or thinner lenses? Will they look stronger if I buy 1.6 lenses?

Cactus Jack, 16 Apr 2012, 14:42


Thanks, I think you are right. Every now and then, one of our cable channels will have a "Bond" week of 007 movies. I probably have seen most of them 3 or 4 times, but never seem to get tired of the Sean Connery and Rodger Moore films. Even though I know how they end, they are great escapist entertainment.


Guido 16 Apr 2012, 14:15

C. J. Twas "From Russia With Love", if I recall correctly.

Cactus Jack 16 Apr 2012, 13:54

I, Glasses,

Most people judge the strength of minus lenses by the "power rings" first and second by cut-in, and third by minification of the eyes if it is noticeable. Power rings are a poor way to judge an Rx because they are caused by internal reflections of the edge of the lens. If the edge of the lens is frosted, the rings will appear white. The thickness of the edge - for whatever reason - will also affect the appearance of the rings. Sometime the frame affects the appearance of the rings. Cylinder can affect the appearance depending on the power and the axis and prism can have a very significant effect by causing more and larger power rings on the side of the lens where the prism base is located.

You can usually demonstrate the source of the power rings by placing your finger on the edge of the lens and noticing how the appearance changes were your finger touches. You may need to lick your finger to assure good contact. You can also see very pronounced "power rings" in trick high minus glasses sold in novelty stores that have no actual Rx, but really look like they do. I can't recall exactly in which 007 movie one of the female villains wore them.

The point of all this is that you can't really judge an Rx by the power rings, cut-in is more reliable, but you have to be looking at the person straight on. If you are looking at an angle, that can change the apparent cut-in. Good luck.


I, Glasses 16 Apr 2012, 08:53

Cactus Jack, I have a question about the look of some lenses. I saw a fellow the other day with rounded-oval-shaped minus lenses and what a layman might say were very thick glasses. However, based on my observation of them, they didn't appear to be terribly thick, but they were evidently a very strong prescription. They could have been high-index, of course, which would account for a lesser thickness. But the circumference of each lens looked, especially when the wearer turned or nodded his head, almost like it was circled in white plastic. The best word I can think of to describe the lenses is 'intense.' I once wore a pair of fairly large rimless aviators with a prescription of minus six, and they had significant edge thickness; but even those glasses didn't have the 'intensity' of the ones I saw last weekend. On other occasions, too, I have seen glasses with minus lenses that didn't seem to be exceptionally thick, but appeared to carry a very strong prescription. Is it axis and/or cylinder that helps give those prescriptions their appearance, or are there other factors at work in such instances? Thanks for explaining this phenomenon for me.

Cactus Jack 27 Feb 2012, 12:24


Another thought. If you would like to have a chart, you should be able to make one in Excel or similar spreadsheet program pretty easily. One thing to be careful about when using the formula or a chart based on it, is that as the Glasses Rx increases, the vertex distance becomes more and more critical because of the squaring of the Glasses Rx. When you get up to around -16, vertex distance effects are just over 0.25 diopters per mm. Conversely, below -5.00, vertex distance effects are so small that CL Rx and Glasses Rx are often the same.

The proof is in the wearing and most ECPs will allow the patient to try more than one power contacts to see which they like the best.


Cactus Jack 27 Feb 2012, 12:11


The formula for calculating CL Rx from a glasses or refracted Rx is pretty easy which is why few if any charts are published. The difference between a refracted Rx and a CL is caused by vertex distance effects on effective lens power. Typical glasses and phropter vertex distances are around 12 mm. CLs have Zero vertex distance.

The formula is:

Glasses Rx squared, divided by 1000, times vertex distance = adjustment factor. If the Glasses Rx is minus, the adjustment factor is SUBTRACTED from the Glasses Rx. If the Glasses Rx is plus, the adjustment factor is ADDED to the Glasses Rx.

Here is the formula in action for a -7.25 Glasses Rx:

-7.25^2 = 52.56

52.56 / 1000 = 0.05256 (diopters per mm)

0.05256 x 12 mm = 0.63 (This is the adjustment factor for 12 mm vertex distance)

-7.25 reduced by 0.63 = -6.62 (This is the calculated CL Rx)

However, CLs in this power range are only available in 0.25 diopter increments. -6.50 CLs would provide slight under correction which would leave the person slightly nearsighted. -6.75 CLs would provide slight over correction which should be easily accommodated and result in extra sharp vision.


Pseldonymov 27 Feb 2012, 11:14

I have a question: where can I find the chart with comparison of the optical powers of glasses and contact lenses?

What contacts are corresponding with -7.25 D glasses?

Thank you!

Soundmanpt 02 Feb 2012, 18:53

Rayray is quite right. There really isn't a need for even the mid hi-index lenses. I order glasses often on-line for people with an even stronger rx and only go with the supplied 1.57 lenses they offer and the glasses look great.

Rayray 02 Feb 2012, 17:00

myopeinhere Specsavers Extra Thin and Light lenses are only 1.57, Super thin and light are 1.67 and ultimate thin and light are 1.74. So no the extra thin and light are not really going to be very impressive - that said the rx is not high enought to need very high index really.

Soundmanpt 01 Feb 2012, 20:52


I also have a question for you. What country are you in? I know that most every doctor here in the US will write you a prescription for glasses for driving at night if you complain about difficulty seeing at night. The rx they write is for -.50 glasses with an AR coating (anti-reflective) It would be a bad idea to try and fake the exam as any doctor will quickly call you out. So I suggest you do the exam without cheating but make sure you point out as much as possible how you are struggling to see driving after dark.

By the way, he/she will put -.50 lenses in the refractor but you will be surprised that you will be able to see even better with those lenses in front of you. Actually what they will be doing is allowing you to see 20/15 instead of 20/20.

I also will not ask you why you only want a written rx, but in many cases the doctor won't give you a written rx unless you ask for even if you need glasses. If your only trying to make someone think you need glasses it might be just as easy to order some nice glasses on-line in a -.50 prescription and you can easily tell whoever that they were prescribed for driving and its up to you if you want to say at night or not.

Cactus Jack 01 Feb 2012, 17:16


Auto-refractors are so common today, it is difficult to avoid their use. Please understand that auto-refractors are not the be all, end all for estimating your actual Rx. Eye Care Professionals are trained to estimate your Rx using a hand held retinoscope or opthalmoscope during the objective part of the exam.

I won't ask why, but I have a few questions that may be helpful in getting you an Rx. We have assisted others before.

1. Your age

2. How much time do you have before you need to get a prescription.

3. Could you order some glasses on line?

4. Even -0.50 glasses would mean that everything beyond 2 meters (6.5 feet) would be increasingly blurry.

While many people with an Rx of -0.50 get by without their glasses, others who like crisp distance vision wear them full time. It is a personal preference.

I you wish to contact me privately use


H 01 Feb 2012, 15:03

Is there some way how I can make my eyes nearsighted for eye exam?

I need to get prescription for glasses. It doesnt really matter exactly how strong unless it is stronger then required for driving.

I have perfect vision now.

If they test my eyes only with table on the wall it is easy I think but all previous eyetests I have had also autorefractor checkup. Is there some way how to pass autorefractor?

BTW. I dont have plan to buy glasses I just need to show out that I would require glasses (for example driving). Please dont ask why.

Julian 28 Jan 2012, 11:52

Euro Traveller: actually the Optical Shops thread was originally started to deal with actual physical shops as against online suppliers - but of course things change with time.

myopeinhere 28 Jan 2012, 10:15

here's one for the uk side of the pond

What index are Specsavers hi-index or thin and light whatever they call them?

my -3.75 and -4.75 don't look very hi-index at all

Soundmanpt 25 Jan 2012, 14:29

Euro Traveller

There are several out there however I have heard cases where you send off your glasses and never get them back. In many cases the prices are not much better than going to a local shop. About the cheapest I came up with was at a Sam's Warehouse and the price was $60.00 including the AR coating.

I know this isn't what you asked but Zenni does a nice job with polished edges, but you have to use their glasses.

Euro Traveller 25 Jan 2012, 12:57

I originally posted this in Optical Shops because I thought that was the right place but as no one replied I'm going to try again here (after all the subject is lens related)...

Does anyone have experience of online reglazing services with particular reference to edge polishing? From reading posts here Cilliary Blue seem to have a good reputation but has anyone used them and specifically requested polihed edges? If so what was the result? if anyone has other suggestions (preferably UK and/or European) I would be glad to hear them.

Thanks in advance.

Revolver 22 Jan 2012, 09:45

Quite often the reason why the temples won't fold properly is the frame design itself. If the frame front is fairly thin and the temple hinges are therefore quite a bit forward, the problem you described can happen.

Take a look at the frames from the top view, if the frame front wraps around even a little bit that means the hinges will be placed further back and there will be no problem no matter the thickness of the lenses. Have used that solution many times.

It brought to mind a customer many years ago that was -10.00 and polycarbonate was the thin/light lens of choice as the hi-index plastics were in their infancy. This particular poly was 1.54 index so there was edge thickness even though the edges were rolled and polished. There was no difficulty with the frame in her daily wear glasses, but she was very specific about the frame she wanted in her sun wear. I advised her ahead of time that the temples would not fold in the sunwear (they were 1.47 CR-39)as she wanted to save money and get the CR-39 and she said no problem. A couple years later she returned for new glasses and gave me the old ones which I still have.

Soundmanpt 21 Jan 2012, 22:06


I have ordered many pairs of glasses from Zenni in different rxs and have never had the problem you are asking about. The first thing I would suggest doing is calling there 1- 800 number and the customer service people are very nice and extremely helpful. I can tell you I often order glasses that are in the -6.00 range and don't even request the hi-index lenses and they look great and certainly there is no problem with being able to close them. Be sure to have your order number handy when talking with them so they can look it up. It sounds as if they somehow didn't use the proper lenses in your glasses. At worst if you are unhappy with them you can return them and at the least get 1/2 your money back, but I am sure if they agree with you that they can't be closed they will indeed refund all your money. I recently placed an order for someone that needed -10.00 with a hefty astigmatism as well and I did order the 1.67 hi-index lenses and the frame she picked was a simple plastic, black, small frame and they looked great and hardly showed any thickness at all.

Do let us know what you find out.

Chrissi 21 Jan 2012, 16:08

Hi all, it's been a while since I posted here.

I last posted on Post your Prescription a few months back when I mentioned I'd be getting an eye exam. It turns out my eye doctor didn't want to give me the exam since I normally wear contacts, and she wanted me to take a break from them for about a week to two weeks prior to the exam so that she could get a more accurate prescription. I'm wearing about -13/-14 ish in my glasses right now. I have an appointment scheduled in February...

Anyway, so I had a question about ordering from Zenni. I ordered the pair that I am currently wearing as well as the previous pair from Zenni. When I first got the pair that I am wearing now, I noticed that the lenses are so thick that I can barely close the arms. The lenses are 1.67 high index. Does anyone have any experience with what Zenni does to help the arms fold over? If the lenses are very thick, do they make the lenses also protrude more to the front of the frame if necessary? Or will they actually send you glasses that don't close? Just wondering since I'm sure I'm going to need a prescription increase in about a month if my eye exam works out, which means thicker lenses for sure. I'm not looking to really get any thinner lens index since I usually get the wider side frames. I hope my question make sense. Thanks!

GL 14 Jan 2012, 06:07


When I was young I used to lick my mother's glasses. She didn't mind it.

Astra 14 Jan 2012, 05:54


never. I assume you have ?

GL 14 Jan 2012, 05:41


Have you ever fogged or licked anyone else's glasses, or have you ever had anyone fog or lick yours?

Astra 14 Jan 2012, 05:13


yes. fogged up lenses...

for me I realize I see better with fogged up lenses than bare eyed.

GL 14 Jan 2012, 05:05


Fogging the lenses is stimulating. Do you fog up your glasses?

Astra 14 Jan 2012, 04:45


yes me too. pushing the lenses back is so stimulating.

GL 14 Jan 2012, 04:41



Astra 14 Jan 2012, 04:37


do you like the frame tight or loose on your nose ?

GL 14 Jan 2012, 04:23


I do wear glasses, but I don't lick the pair I wear.

I have over 20 pairs of glasses I have bought just for licking. Big frames with very thick lenses. I lick them because I enjoy doing it. I have 'fun'.

Astra 14 Jan 2012, 04:14


but I assume you must have try to wear your licked lenses for fun , some time ?

GL 14 Jan 2012, 04:08


I buy glasses with thick lenses just for licking. Never to 'see thru lenses'.

Astra 14 Jan 2012, 04:03

Yes. a different perspective from the usual, functional "see through the lenses".

licking lenses is more alike to touching lenses etc.

GL 14 Jan 2012, 03:58


Licking the back is better. Especially with really thick high minus lenses. I have two pairs of glasses with -12 lenses in them, and licking the back of them is awesome.

Astra 14 Jan 2012, 03:51


yes. why not ? ...

The back side has a higher curvature.

GL 14 Jan 2012, 03:23


Do you lick the back of your lenses?

Astra 29 Dec 2011, 06:12


For licking I would prefer polished edges. I like the smooth curvature.

For wearing... I don't have preference. both are fine.

GL 29 Dec 2011, 04:49


Definitely unpolished edges and the lenses at least 10cm thick. Which do you prefer?

Astra 29 Dec 2011, 04:24


If you are given choices, you prefer to lick lenses with unpolished edges, or polished edges ?

GL 29 Dec 2011, 04:09


I agree that most people would think licking lenses is weird. Though, I have seen people do it in public.

I only lick lenses in private. And I love doing it.

Astra 29 Dec 2011, 03:57

because it's private.

Most people consider licking lenses weird, some may make comments when you lick the lenses.

GL 29 Dec 2011, 03:40

Why in toilet/bath?

Astra 29 Dec 2011, 02:17

Re: GL 28 Dec 2011, 23:56

Lick your thick lens. best in toilet/bath

GL 28 Dec 2011, 23:56

Thick lens = lick lens.

Astra 12 Dec 2011, 18:45

In case for anyone interested in the theory of "Snell's Law of refraction",

The Snell's Law of refraction can be derived by the following method:

1. "integration by parts" of the equation for evaluating "optical path length", in the 2 surfaces in contact with the required medium.

2. minimizes the difference between the 2 terms obtained. The "Snell's Law of refraction" can be obtained.

Thus all required before step 1. is to have the continuity of the light ray verified.

Slit 04 Dec 2011, 06:52

thanks euro traveller!

Euro Traveller 04 Dec 2011, 05:32

Here is some English language information from the Hoya site (using a pic of the same model)

Euro Traveller 04 Dec 2011, 05:29

It is an advert for a new 1.74 index lens called Eyvia made by Hoya.

Slit 04 Dec 2011, 05:09

Can anyone reading polish tell what this article is about please?

GOCer 29 Nov 2011, 20:59

I think biconcaves are sexier. I like the edge thickness, power rings, and extra reflections!

specs4ever 28 Nov 2011, 13:23

biconcave myodisc is the most seldom seen, and is my favorite - especially in a very high power such as a -40 done in hi index glass.

Lentyop 28 Nov 2011, 09:01

Superlenti/Lentilux/Blended Myodisc are my favorite.

varifocals 28 Nov 2011, 05:08


I agree.

Astra 28 Nov 2011, 04:30


I would say myodiscs.

RL 27 Nov 2011, 13:45

Which are the most sexy lenses; biconcave or myodisc?

Astra 03 Oct 2011, 04:57

Concave lenses can increase the angle of corrected peripheral vision from your uncorrected, come close to normal eyesight.

Astra 03 Oct 2011, 00:14

Another phenomenon you may try,

increasing the distance of your lens from your eyes.

Around 10 cm is enough. See if the correction is still good enough.

There's an inverse relationship in this phenomenon...

Astra 03 Oct 2011, 00:12


This allows the best image to form in eyes.

Also a wider angle of corrected peripheral vision.

Think about it, glasses are already restricting your peripheral viewing angle.

Myopia also decrease the angle of uncorrected perhiperal vision. Concave lenses can increase the angle of corrected peripheral vision from your uncorrected, slightly restricted peripheral vision.

Of course at 3 diopter it's less noticeable. Things get a little worse at higher rx.

Melyssa 02 Oct 2011, 11:04

I just tried this, and I can see almost the same as normal, if the angle is within a slight range near the center. It's not something I would want to try for more than a few seconds.

Cactus Jack 02 Oct 2011, 10:28


Lenses work the same in both directions. The Rx is the difference in the front curve of the lens and the back curve. Having the front surface have a convex (plus) curve is aesthetically more pleasing and it produces less distortion than having the front surface flat (0.00) or concave (minus).

For example, a -2.00 lens might have a +1.00 front curve and a -3.00 back curve and the result is a -2.00 lens.

There are many posts here where people who need high minus lenses complain of distortion with flat front lenses or bi-concave where both the front and back curve is minus. They often decide to go to myodiscs to reduce the distortion,

The ideal place for lenses for the eyes is right where they normally are. The next best place is on the cornea and the worst place is glasses. However, glasses are very convenient and don't require much special care.


Soundmanpt 02 Oct 2011, 10:27


Next time you are playing with your glasses and looking through them backwards instead of looking through the center of your lens at the board in front of you try looking out to the sides through your lens and I think you will find it is much harder to see that way. When wearing your glasses properly your glasses will give you much better vision on the sides because of the shape of the lenses.The lenses on your glasses are shaped outward to match the shape of your eyes which are rounded outward as well.

Flaine 02 Oct 2011, 09:56

Not sure if anyone knows the answer to this weird question.

Toying with my glasses during a lecture on the other day, i realised that when i look through the glasses from the opposite direction, the pens is still able to Correct the myopia as compared to the pproper position that glasses should be worn..this has kinda bugged me for awhile.. Question is, since concave lens are used for the correction of myopia, why are we able to see it through the opposite direction? Unless the physics behind it is that both sides of the lens are designed to correct myopia, but since the side that curves inward( normal myopia lens), it is mpoe aesthetically pleasing and thats why its been made this way all along, as opposed to the edges jutting outwards, away from the eyes?

Anyone can explain?

Brian 30 Sep 2011, 11:27

Thanks.. At least I know what I am seeing is normal with the BI prism correction. Hopefully it will stablize at some point before the prism gets too strong or my eyes will be pointing out of the side of my head. I don't have another exam scheduled until February, so I don't expect any changes until then.

Cactus Jack 30 Sep 2011, 09:38


Prism seems to be more noticeable with plus lenses than minus lenses and needed more often with hyperopes than myopes.

The cause seems to be related to the strength of the interconnection in the brain between the eye muscle control system and the focus control system. The interconnection is seems to be a two way connection where the act of convergence to look at something close triggers the ciliary muscles to contract and add plus to focus. Also, focusing close also triggers the convergence response.

When a person is hyperopic (need plus glasses) their ciliary muscles must squeeze the crystalline lenses to add some plus to see distant objects clearly and then squeeze some more to focus on close objects. The result can be a convergence response (crossed eyes) and double vision.

Sometimes, eye muscle exercises can reduce the strength of the connection and help, sometimes the solution is prism, and sometimes muscle surgery works. Age seems to be a factor in the success of any solution. Eye muscle surgery only affects the 6 tiny eye positioning muscles and not the eyeball itself, with one exception.

One type of surgery for crossed eyes involves moving the inside muscle (medial rectus) attach point back on the eyeball. The advantage there is that there is no scar tissue (which is not flexible) as there is when the muscle length is changed. The effectiveness of eye muscle surgery seems to be strongly related to age. The younger the better. There are several adult members who have had muscle surgery and ultimately still needed prism in their glasses.


prismbaseout 30 Sep 2011, 08:29

Hi there

I wear prism glasses with 12/12 base out prisms, additionally to that I am slightly farsighted (+1.25 in each eye). My girlfriend tells me that my eyes very much look cross-eyed, sometimes I feel as if it is almost not noticeable, but usually if I see my reflection in the mirror I also see that the eyes are crossed. I don't particularly like that but without the prisms I have double vision which is worse. My eye doctor also suggested to me to do surgery but I don't like the idea of muscles being shortened and of surgery on the eye in general.

Cactus Jack 29 Sep 2011, 22:26


One prism diopter results 0.57 angular degrees so 3 BI results in 1.71 degrees of outward deflection. Which isn't very much. It is possible that it is a bit more or less depending on the location of the optical center of your glasses.

It is possible that your current prism Rx is under corrected. I wear 7/7 BO (sometime 15/15 BO) and the 7/7 BO is not very noticeable, but the 15/15 BO is, mostly because of the edge thickness.

I don't know why BI prism is more noticeable, but it is. It may be that because there is no need for the eyes to turn outward past parallel for distant object and it is normal for the eyes to converge for viewing objects closer than 20 feet or 6 meters that we just don't notice when the eyes are converged and we do notice with they are diverged.

More than 15/15 BO is very noticeable.


Angie 29 Sep 2011, 21:37


I have 6 base out in my lenses, and I do try to avoid wearing them often because my eyes sit too close to my nose when they are on. After wearing them for some time, and then removing them, I need to sort out double vision, and wait for my eyes to not look crossed without the lenses on. At my last check-up, my doc broached the subject of eye muscle surgery, of which I want no part of; when I don't wear the base out glasses, my eyes look generally okay, just have eye fatigue in my right eye, as that one is far-sighted. I don't want to reach the point where I need to wear them all the time, so I make do with glasses without the prism, and I save the prism pair for days that involve a load of reading. Keep us posted on how things progress...


Brian 29 Sep 2011, 16:09

Has anyone with Base In Prism lenses noticed they are more walleyed after wearing the glasses? I've really started to notice my eyes sitting out more when my 'script increased to 3D BI in each eye. It was 2D BI before. Is this normal? I hope this isn't a sign of needing more prism at my next visit. Before getting prism in my glasses I never remember my eyes sitting out like that, but now when I look in the mirror they are pointed out a bit. My eyes do feel fine with the glasses on.

Leo 27 Sep 2011, 07:21

HI GOGer. I'am wearing -13's with 10mm thick lenses from Zenni.

GOCer 27 Sep 2011, 07:08

On Zenni's website the 1.5 index lenses top out at a measly -6. And even if they went higher, are the lens blanks going to be thick enough or will they crap out at 13mm?

Soundmanpt 27 Sep 2011, 01:26


You can order lenses from Zenni in 1.50 thickness up to -8.00. Not sure if you called them they might even consider going higher than -8.00.

GOCer 26 Sep 2011, 20:53

How thick are lens blanks made these days? Zenni's "1.57 mid index CR-39" seems to top out at 13mm (had a few high scripts run out of blank at the edge). A few years ago I seemed to be able to consistently get 15mm thick biconcave lenses, etc at various outlets. I also tried to get to make a low-index CR-39 pair in -10 to see what would happen but after much back and forth with customer service it appears they threw in a very high index lens for free and they came back very thin.

Anyone had any luck getting thick glasses anywhere lately? :)

DWV 28 Aug 2011, 09:53

There were at least 80 mm blanks. In the 80s, 60mm eye size lenses weren't unusual. My old aviators are 59-15, with glass lenses.

X-Cel Optical shows 81 mm lenses available in many styles of resin lenses, and 76 mm in glass.

Galileo 16 Aug 2011, 14:46

It's a few years since I had any involvement with the optics industry, but then the largest readily available lens blanks were 65mm diameter. there were two smaller diameters but I can't remember the sizes

Soundmanpt 16 Aug 2011, 11:53

I have been trying to get the information about the various sizes of lens blanks that are available. I have asked several of my friends that are opticians and they don't even know. Hopefully I will have the answer soon. Great question.

Lunettes 16 Aug 2011, 10:35

I have seen onle lenses that are manufactured optical center at middle of lens.

If getting rx lenses to sunglasses,witch are big at these day,lense size gives trouble.

My Tom Ford alessandra frames size is 65, no rx able.

Maybe possible to make special lens order but , maybe too expencive.

Cactus Jack 14 Aug 2011, 09:24


Yes, but the lens maker does not have to grind the lens with the optical center of the lens in the center of the blank, but there are limits on how far it can be offset. Why are you concerned about blank sizes? That is the lens makers problem.


Lunettes 14 Aug 2011, 08:56

If eyes are close to nose, small pd. and frame is big,wide.

That would take larger diameter lens.

Cactus Jack 14 Aug 2011, 08:06


Could you help out here. I don't know what Blank sizes are available. 65 mm comes to mind as a large blank, but I am not sure that is right. I think a large "aviator" style frame would need a larger blank than that.


Cactus Jack 14 Aug 2011, 08:00


Lens Blank size is NOT directly related to PD. PD is the distance between the pupils of your eyes when you are looking straight ahead at a distant object. When they make glasses they cut and mount the finished lenses in the frame so that the Optical Center (OC) of the lenses is the same distance apart as your PD, typically 55 to 70 mm apart in adults.

Lens blanks come in different sizes. The size selected is related to the size of the frame. Typically, when the lens is mounted, the distance from the PD related OC to the inside edge of the lens (next to the nose) is smaller than the distance to the outside edge of the lens. The final lens, before cutting to fit the frame, must be large enough so there is some lens to cut away at the outer edge. Otherwise there would be a gap between the outer edge of the lens and the frame.


Lunettes 14 Aug 2011, 07:36

How big Blank lenses are, diameter, i ment.

Lunettes 13 Aug 2011, 10:10

How big bplak lenses are, how big frame can be fitted with rx lenses.

Pd must do something for needed size.

So many 54 size frame, but bigger would be needed.

Tom Ford have some new out with 58 size.

Cactus Jack 31 Jul 2011, 13:02


What Clare said is very true. The cornea normally has no blood supply to provide oxygen and improperly fitted contact or the wrong kind can block oxygen and tears from reaching it.

Oxygen starvation and other things can cause blood vessels to grow into the cornea and ruin its optical characteristics.

As an incidental bit of knowledge, the way they proved that a cancerous tumor had the ability to force the body to supply it with blood was to place a tiny bit of tumor tissue on the cornea of a rabbit and a blood supply soon developed to it.

On the surface this may seem a very cruel experiment, but it proved that the theory was correct, which led to some breakthroughs in cancer treatment to block the hormones that cause the blood supply to form and thereby, starve and kill the tumor without radiation, chemotherapy, or surgery with their associated risk, pain, or discomfort.


Clare 31 Jul 2011, 11:12

Lisa - not worth the risk. I've had to try several different brands to find one that's comfortable and its well worth having a patient optician when that's the case. You could be lucky and be easily tolerant of contacts, but even so you need to know how to look after them. A friend of mine was told she was over-wearing hers and veins were growing into her eyes - that's a really dangerous condition that happens when you wear them too long. So you need to know all the risks before you start, just to be safe.

Aubrac 26 Jul 2011, 09:30


Sorry to bang the drum, but if contacts do not fit correctly, parts of the cornea can become starved of oxygen which means blood vessels rise to the corneal surface to get more oxygen.

Once this has happened, and you will not be aware of it because it is for the most part painless, it is irreversible and will block light rays entering the eye giving rise to shadow patches in your field of vision.

Not something you really want.

Soundmanpt 22 Jul 2011, 08:22


Yes by all means don't purchase any contacts until you have a fitting done. Many places will often times if your glasses rx is less than 6 months old they will wave off the eye exam charge and only charge you for fitting contacts, much cheaper.

You didn't say what your glasses rx is but if your more than -3.00 your contacts can be a bit different rx than your glasses.

But Aubrac is correct you can do serious damage to your eyes if the fit isn't correct.

Aubrac 22 Jul 2011, 02:16


Contacts Contacts have to be fitted to the correct diameter and base curve for your eyes. Once this is known you can order contacts online, etc.

The optician will put in trial lenses and and examine your eyes to ensure the fit is correct. This is most important otherwise it can result in damage to the cornea, also some people have a condition often called 'flat eye' which means they find it very difficult or impossible to wear lenses.

It really is necessary to have contacts properly measured and fitted or you could risk damaging your eyes. In the UK an eye test is about £15 with an extra £10 for contacts testing.

Lisa 22 Jul 2011, 02:07


I have a prescription for glasses and have never worn contact lenses before. Would it be possible to buy contact lenses from an optician without never had a fitting?

Rayray 21 Jul 2011, 17:06

Contacts causing pain after coming out is a sign of over-wear and the cornea desperately sucking in oxygen that it has bee starved of - give your eyes a break!

Soundmanpt 21 Jul 2011, 10:42


I am only backing up what "specs4ever" and "Cactus Jack" have said only maybe even stronger. They are correct and I recommend you not wear your contacts again until you see an eye care professional. I think you will be told to stay away from contacts for awhile and as stated it could be a different type or brand may be a better choice for you.

Good luck and do get it checked out.

Cactus Jack 21 Jul 2011, 10:13


I agree within Specs4ever. I also urge you to see your Eye Care Professional very soon. There may be something going on with your corneas. if there is, you need to find out about it NOW and do something. Corneal problems are nothing to trifle with. If they get in trouble, they heal slowly and sometimes, not at all.

The corneas have no blood/oxygen supply, they must depend on oxygen from the air and tear film for their moisture and nutrients.


specs4ever 21 Jul 2011, 08:43

Baker, if our eyes are hurting before you put in your contacts, I would strongly suggest that you go a couple of days without wearing your lenses. The hurting when your lenses are out only means that your eyes are trying to heal, and to put your lenses back in only increases the problem. It may create a big enough problem that you will have to do without contacts in the future.

However, I am not an expert, so I suggest that you visit your eye doctor. Possibly a different brand of contacts might help.

Good luck

baker 21 Jul 2011, 01:33

Does anybody else find that their eyes feel dry and uncomfortable even more/only when they take out their contacts? At least initialy? Like if your eyes are bothering you and you put in contacts it will still hurt for a bit but then feel better or when you take your contacts out that's when they start hurting or when your eyes hurt, you take out your contacts and then your eyes only bother you more?

Does anybody know why that happens?

And 27 May 2011, 17:37

My gf wears daily disposables without any problem - all day, every day.

Aubrac 27 May 2011, 03:31

I think it is luck of the draw when it comes to contacts. I am fortunate in rarely suffering from dry eyes and don't have a problem with extended wear.

I remember my first contacts were hard micro-corneal lenses, not very comfortable and prone to popping out often with embarassing results. I also tried so called 'perma-wear' lenses I wore 24/7 for several months but gave these up as they were not healthy for the eyes.

Present lenses are high water content 2 week disposable that I find very comfortable.

Clare 25 May 2011, 14:30

Very Progressive - you're lucky, not everyone has such a good experience. I find I can generally wear my lenses for about 12 hours before they start to get uncomfortable which isn't always convenient when the working day sometimes extends to 14. On the other hand there are the rare occasions where 14+ hours is okay, which just goes to show its a very subjective thing. Working in air conditioning doesn't help of course and the PC is a known devil for causing discomfort. Glad its going well for you.

very progressive 25 May 2011, 08:13

I am new to contact lens wear. (just a few days). I was dx'd by my allergist, as having dry eye syndrome. I also have a little bit of allergic conjunctivitis. I was very dissapointed, as I thought contacts were out of the question. I am needing multifocal lenses, hence knowing they can be difficult to fit, contacted " a contact fitting expert." I had never seen this optometrist before, but was told that I would be best off finding a Dr that is very confident with regards to fitting bifocal lenses, and or monvision.

I called this Dr's office after researching online, and asked not only about the need for bifocals, but the dry eyes. I was told that dry eyes go with the territory at my age, and expecially with alot of computer use. He was not concerned. Long story a little shorter. I am pleasantly surprised to find that wearing the contacts ( high H2O content ) is actually mcuh more comfortable than not wearing them? Is this possible? As I am adjusting , must wear for limited # of hrs, with daily progression. Couldn't wait to get lenses in this morning, as eyes felt horrible , even with drops. Wanted them back in last evening, almost immediately after taking them out ! Now just to fine tune the rx. (hope this can happen), and I'm happy camper ! In adequate vision for computer with progressive glasses! Not comfortable with the glasses, as they make me feel odd !

Soundmanpt 27 Apr 2011, 01:02


Yes, but even $10.00 for something that don't work is still money wasted. What you have there is junk.

miranda 27 Apr 2011, 01:00

It seems the lenses are made incorrectly and not up to desirable quality.

I can leave this pair aside.

I would not remade. this pair of lenses is made one year ago.

After reading some of the online reviews of that store, it seems that store does have quality problems.

The price is low ($ 10 for frame and lenses ), but the service and products are not good.

Soundmanpt 26 Apr 2011, 08:22

I meant to say "at no additional cost to you".

Specs4Me 26 Apr 2011, 07:43


Wearing those glasses is certainly going to create discomfort for you, don't think there is any danger to your sight.

The solution is to have them remade, if they are fairly new the opticians should do so an no cost to you.

Soundmanpt 26 Apr 2011, 07:42


It would seem that your new glasses were made incorrectly and as antoniio says the optical store should remake them at additional cost to you,

miranda 26 Apr 2011, 05:24

antonio, I have other pairs of lenses with the same prescription, the focus is correct in other pairs.

I am more concerned about whether this is a condition that indicate I should not wear the pair with too low optical center.

antonio 26 Apr 2011, 05:14

hi miranda,

seems you should check your eyes at an eyedoc

and your glasses at an optician again:

You said:

The optical center of my lenses is too low for my eyes.

perhaps it´s their fault and you don´t have to pay money again.

perhaps those glasses are too strong for you even for far.

I suggest you wear some older perhaps weaker pair for a day and you try you have the same focussing problems with those.

If yes, might be your eyes, if not should be these special glasses or the prescription too strong, center too low, etc.

please tell us again,

best regards,


miranda 26 Apr 2011, 05:02

antonio, the focus problem affects both distance and near.

antonio 25 Apr 2011, 14:10

I´m not an expert, miranda

and probably it´s best you visit an eye doc,

but could it be you need bifocals or just an older

weaker pair to read nearby ?

Would this help you to read nearby ?

best regards, antonio

miranda 25 Apr 2011, 02:28

The optical center of my lenses is too low for my eyes.

Is this a possible cause of strain sensation when wearing the glasses ?

I could not focus good enough for reading books after wearing for a few minutes.

By then, if I take off glasses I cannot focus as I did right before I put on the glasses just few minutes ago.

Cactus Jack 18 Apr 2011, 20:13


Anti-reflective Coatings are technically very complex and the tint of the little light that gets reflected depends on the materials used, the number of different layers and even the index of the lens materials. The coatings are usually atoms thick. The color or wave length of the light that gets reflected depends on all these. Some are violet, some green, some brown depending on the purpose of the lens and the process used.

What they are not is a grating. You may be thinking of a deffraction grating that is used to split light in to colors and cause the reflections to scatter in different directions. You can see deffraction grating effect by looking at light that is reflected from the surface of a CD or DVD. Curiously, a deffraction grating like effect can occur in nature. Some butterfly wings and bird feathers will reflect different colors of light depending on angle from which they are viewed. Some male hummingbirds in effect put on a light show with their feathers to attract a female with brilliant iridescent colors by changing the angle of their feathers. The females are VERY particular about the quality of the light show in choosing the father of her offspring.


LikeGlass 18 Apr 2011, 19:58

The AR coating has a bit of the Dichroic effect, so on axis color may be different then off axis color. Most ARs look green to me when viewed with a reflection that is straight on.

The effect is an unintended consequence of the coating.

Here is some info on the Dichroic Effect:

miranda 18 Apr 2011, 19:18

I was told that anti-reflection grating appears violet in color.

My prescription is in -8 range, Why is there a coating that appears green on my lenses ?

Aubrac 21 Mar 2011, 10:43

I want to get rid of scratches on some lenses, could I do this using a buffing wheel and toothpaste, and would it change the optical properties of the lenses?

Cactus Jack 21 Mar 2011, 09:25


Yes, it is. Generally, the Chromatic Abberation near the optical center of the lens is hardly noticeable and it increases as you move away from the OC and it is at it worst near the edges. Most high index materials until you get to the high index optical glass lenses, do not have very good "abbe" values. There is a price to pay for thinness not necessarily related to money. CR-39 is hard to beat for optical properties in plastic lenses, but the price you pay there is thickness.


meg 21 Mar 2011, 08:48

I have also noticed that there is a slight orangey tinge to the edges of objects, my prescriptio in -4.00 and -4.50 Aand ive got the ultra high index lenses, i see this orangey tinge if i look out of the cornner of my eye, if i face something straight on, i dont see this tinge, is this normal?

Cactus Jack 20 Mar 2011, 23:19


Usually, the lower index materials, particularly CR-39, have excellent "abbe" values which generally mean excellent Abberation characteristics, including chromatic, but there is still some. It is only a question of how much.

I would say that you are particularly observant.


baker 20 Mar 2011, 21:26

Thanks. I'm glad that I'm not the only one who sees that. I asked some friends if they saw the outlines when they wear glasses and neither of them did.

I don't have any prism correction. I don't think my lenses are hi-index because their rx is just -3 and -2.5 but I didn't buy them myself nor did I know anything about lenses at the time.

Brian 20 Mar 2011, 18:16

Baker and CJ.. I noticed that same effect you were talking about with the prisms as well.. I never noticed it when I had 2D Base IN in each eye. But with my prescription increasing to 3D Base in in each eye now I notice the reflections on the outside edges of the glasses.. At first it bothered me a little bit, but after having the glasses for a month or so now I hardly notice it.. With the increased thickness on the inside edges, I notice from time to time when on the computer I can see the inside edge of the lense a bit.. But now after getting used to the glasses its not as noticeable.. As you said the brain kinda blocks out some of those minor distractions.

Cactus Jack 20 Mar 2011, 09:19


Those are the effects of prism. Prisms bend different wavelengths (colors) of light by different amounts which results in separation of white light into all its

component colors.

Remember that lenses are actually an infinite number of very thin prisms arranged with either their apexes at the center of the lens in a minus lens or the bases of the prisms at the center of the lens in a plus lens. The amount of fringing depends to some extent on the lens material and the strength of the lens. Of course, if the lens also includes prism correction the the fringing effects are increased.

I don't recall your Rx, but if you wear prism correction, you may notice that the blue and orange fringes are on opposite sides of an object in your left and right eyes. People who wear significant prism correction initially notice the fringing, but because vision actually occurs in the brain, the brain will soon lean to ignore the fringing and you will no longer notice it.

I wear some BO prism and I have noticed an interesting effect when looking at LED (Light Emitting Diode) signs in Yellow (actually done with a Red and a Green LED) I actually see a Red and a Green image with a slight separation of the two images. This is caused by the fact that LEDs emit light of only ONE wavelength. The prism separates and bends the Red and Green light by different amounts and the result is two distinct images.



Danny 20 Mar 2011, 09:17

The Violet/Red images are normally associated with Hi-index lenses.

It's all to do with the lenses refracting the 7 colours of light differently. However, my Physics knowledge is no longer good enough to explain why.

Do you have the same effect with non-high index lenses.

(Sorry, I'm assuming that you have hi-index)

baker 20 Mar 2011, 04:23

When I wear glasses, I often see a blue outline on one side of a person/object/light and an orange outline on the other side. Is that just a function of lenses bending light in general?

Cactus Jack 03 Mar 2011, 20:23


The deflection angle of a ray of light passing through a lens (which is actually an infinite number of very thin prisms arranged in a circle. A plus lens has the bases in the center of the lens and a minus lens has the base on the periphery of the lens) or a simple prism, is a function of the Index of Refraction of the material. Prisms of higher index materials have thinner bases that lower index materials for the same angular deflection.

Recently, I asked a local vision center what was the highest prism Rx they could do. The reply 10 diopters in CR-39 or up to 30 using the highest index material they offered. In many cases, the maximum prism is governed by the capabilities of their lens generator (lens grinding machine). Remember, they start with comparatively large, thick lens blanks and have to grind it into a plus or minus lens with one edge very thick and the other very thin without breaking the blank in the process. It isn't easy. What you wind up with mounted in the frames is about 1/2 or less of the total volume of the lens material.


Brian 03 Mar 2011, 13:40

One interesting thing I was thinking about Prism Lenses...does the thickness of the Prism Lenses remain the same no matter what type of lenses you get in your glasses.. Eg.. Is the actual thickness of the Prism the same whether you order CR-39, Polycarbonate or High Index Lenses or does the index of these lenses affect the prism as well? I'm only on my 2nd prescription with Prism lenses but for future reference because my prism seems to likely increase in the future, is it worthwhile ordering the ultra high index lenses to cut down on the thickness of the prism or will that stay the same no matter the type of lenses... Thanks..

danny 18 Feb 2011, 01:48

Thanks a lot. I will try that!

specs4ever 17 Feb 2011, 18:07

And toothpaste works just as well, and is easily obtainable in your own bathroom.

Stingray 17 Feb 2011, 11:39

You need to buy this stuff called "plastic buffing wheel compound" It's a cylinder of this hard white stuff that you place on a spinning cotton buffing wheel. I bought it from this place called Visioneering Optical Supply. I bought it about 10 years ago and still have 90% of it left. It lasts forever and 1 stick of it and you can polish thousands of lenses.

You can polish the rough edges of any plastic lens in about 2 minutes time.

specs4ever 17 Feb 2011, 09:14

I have often made "myodiscs' out of very thick lenses. I use 24o grit on a metal base, and thin the lens down to the point that I want it. Then I use progressivly finer sandpaper to eliminate the scratches. I have gotten down to 2000 grit water paper, but usually 1500 grit is Ok. Then if you take toothpaste on a buffing wheel you can polish the lens so that it is perfectly clear. And if you don't have a buffing wheel, you can also use a buffing wheel in a cordless drill. Just take it easy with a lot of care and you should be all right. Good luck!

danny 17 Feb 2011, 06:26

I have a question regarding grinding/polishing lenses (specifically the edges):

I have a pair with very thick lenses which I want to grind down flat (a little like lenticular). That is no problem with common sand paper.

But what I would like to accomplish is a clear polish and I wonder how to do that. Doe sanyone know what grain size might be working or what extras I would need. I hope I don't have to do it with a sponge polishing for a month.

Any insight is very much appreciated!

lentifan 21 Jan 2011, 11:33

The term 'pebble' glasses or spectacles, as used in Britain, would not, I think, be understood by most people nowadays to refer to lenses actually made from pebble material. Rather, as Cactus suggests, it would indicate a lenticular or (perhaps more likely) a myodisc lens. These might resemble to the uninitiated onlooker a 'pebble' set within the carrier.

I think the term is less common than it was, perhaps because such lenses are also less common.

Cactus Jack 21 Jan 2011, 02:26

Like Lenses & Penny,

An excellent link and well worth downloading and reading. I stand corrected.


Like lenses 21 Jan 2011, 01:57


Continue reading past page 5 for additional info.

Like lenses 21 Jan 2011, 01:49


Here is a link to an interesting history of lenses. It is a long read,but pebble glass is discussed on page 5.

Cactus Jack 20 Jan 2011, 18:14


I am not sure, but it is possible they were referring to the very strong plus glasses that used to be worn by people who had had cataract surgery. Before Intra ocular lenses (IOL) became available, when a person developed a cataract, which is typically a clouding of the crystaline lens, the only solution was complete removal of the lens and its capsule. The crystaline lens has a nominal power of about +15 diopters and to provide reasonable vision, it was necessary to wear glasses in the +20 range.

High plus lenses in that range look like a section of a small glass sphere about the size of a small pebble, which might explain the name. Today, we would call lenses like that "lenticulars".

Fortunately, today, cataract surgery is no longer a very serious surgery with a long recovery. Typically, cataract surgery is an outpatient procedure of only a few minutes where a tiny (about 3 mm) incision is make at the edge of the cornea and very tiny instruments open the crystaline lens capsule, emulsify the clouded crystaline lens, and remove it. Then a flexible IOL, which is rolled into a small tube, is inserted through the incision and allowed to unroll. The lens is then positioned where the natural was and the incision will often close without any stitch. Anti-biotic ointment will be applied and the eye will be bandaged with a protective shield in place.

Typically, the next morning the bandage and shield will be removed by the patient and in an hour or so, the antibiotic ointment will wash out with tears and depending on the power of the IOL, that eye will see nearly 20/20 or better.

With the advent of IOLs, cataract or pebble glasses are no longer needed and only those few people who have severe hyperopia need to wear very high plus lenses in their glasses.

BTW, the discovery that you could put plastic IOLs inside the eye occurred by accident some years after World War II when an opthalmologist in the UK discovered some pilots who had slivers of acrylic plastic (perspex or plexiglas) inside their eyeballs without apparent damage or harm to their vision.

I hope this helps.

By the way, I have had cataract surgery in both eyes and it was the nearest thing to a surgical non-event I can imagine.


lucspecs 20 Jan 2011, 16:05


thanks for the info, I may well give them a try.

PENNY 20 Jan 2011, 15:03

In reading over the years,esp.British,I have come across the word "pebble spectacles". The wearer was, thus, referred to in a sort of derogatory term(s). Can anyione define PEBBLE SPECTACLES? I can think of the earlier myodiscs which did seem to be small pebbbles imbedded into a lens in a frame, and for the obvious reasons. BUT I can not find the true definition. Help would be appreciated./PENNY

Clare 20 Jan 2011, 13:33

luvspecs - a friend of mine uses them, that's how I heard about them. And yes, they're very cheap. I don't generally wear disposables but I wanted to see if I could so I ordered some and was pleasantly surprised. Their customer service is excellent, they answered an initial enquiry promptly and followed up after my order was delivered. Nothing to say against them.

luvspecs 20 Jan 2011, 12:44

I came across an interesting site yesterday, They sell contact lenses very cheap. Has anybody here used them ?

John S 20 Jan 2011, 12:00

I have tried many brands of progressive lenses. I have found one that almost makes me forget I am wearing progressives. It is the Hoya Summit ECP. I like a high add for close work, these are available up to a +4.00.

The other advantage is, they have a long drop zone. That means, there is a longer, smoother transition from far to near. More intermediate area to work with.

These are so comfortable, when I come home and get on the computer, I sometimes don't bother using my single vision computer glasses.

They are not inexpensive lenses. I have a friend of mine that has a optical store. I think they were about $125. I would expect they will be much more in the retail market.

If they are fitted correctly, I think you will be very happy with them.

I, Glasses 20 Jan 2011, 10:01

For any of you who have had experience with progressive lenses for the correction of myopia-with-presbyopia, what is your recommendation for the best brand of progressive lenses, those that give the best vision and largest fields of view in the mid- and near-vision range?

Astra 29 Dec 2010, 06:26

Is this lenses before fabrication?

Astra 29 Dec 2010, 05:37

An excerpt from the following article:

"According to an American survey, the most annoying thing about wearing glasses is how dirty they get, and how often they require cleaning. The survey revealed that 93% of wearers clean their glasses on a daily basis, and 64% admit to cleaning their glasses more than once a day. With all the wiping and polishing of glasses that goes on everyday, is it any wonder we break our frames or scratch our lenses from time to time? "

sam12744 18 Dec 2010, 18:27

RT, has to be the place, although their range of frames can be a bit limiting.Quality is good, but, as you might expect, the price of such "strong" glasses is high.

RT 16 Dec 2010, 08:56

Any recommendations for myodiscs please?

Crystal Veil 16 Dec 2010, 07:51


you wrote recently about how surprisingly thin Zenni glasses with 1.67 lenses in the double digits were. I had an even bigger surprise last week when some new Zenni glasses arrived. I ordered standard 1.57 lenses for all glasses. Most glasses have Rx L=R -8.00 but one pair has L -11.00 / R: -12.00 and lens thickness is less than 4 mm. Incredible. The lenses look different than the -8.00 lenses in the other glasses. Almost like rock crystal. A big surprise. I will have a photo shoot in spring with a model that has exactly that prescription and no doubt, she will be pleased. Perhaps Zenni made a mistake. I only paid $ 9 extra for the Rx above -8.00 so it's a bargain.

Soundmanpt 17 Nov 2010, 12:10

Thanks Cactus Jack I should have been a little more clear about that.

Cactus Jack 17 Nov 2010, 10:23


To amplify a bit what Soundmanpt said, in some countries (the US for example) glasses must be a certain minimum thickness for safety reasons. The US requires a test of lens strength before they can be delivered. Online retailers, outside the US, are not required to perform this test. This results in thicker centers in the US for minus lenses, which results in thicker edges. Some very strong lens materials with higher indexes of refraction than CR-39, polycarbonate for instance, can withstand the test with surprisingly thin centers.


gwgs 17 Nov 2010, 09:40

Thanks for the response Soundman - maybe the lab technician kept it as his secret as the lady I conversed said that CR39 lenses had been used, as this is what had been requested, but even with 1.74 index lenses they should have been a couple mm's thicker.

Anyhow, the missus didn't approve of them and hence why they were sold at a loss! :(

Soundmanpt 17 Nov 2010, 08:45


My first guess to be that different would be that they used high index lenses maybe due to the style of the frame. The frame looks like it might be a drill mount and that would be very thick with CR 39 lenses. The lab person may not have had any choice but to go with thinner lenses to make it work? Being a smaller frame of course will cut down on edge thickness as well. But I really think that due to difficulty of using CR39 lenses it was worth giving you the more expensive lenses at no additional cost.

I got glasses from zenni for a client about 7 months ago and her rx was -10.00 and she had -2.25 cyl I did get them with 1.67 high index lenses in a small plastic rectangle frame. I was very shocked at how thin they were. So much so I even had the rx checked to be sure the rx was correct. It is true also that being made in Hong Kong the lenses are thinner anyway.

gwgs 17 Nov 2010, 06:48

Soundman, and others, maybe you can help with this?

I recently had these glasses reglazed - this is the photo after they had been done -

I had a -9.75 prescription fitted in them, with no cyl and standard CR39 lenses. However, when they arrived, the lenses were remarkably thin for this prescription, they are just 4mm thick. I thought then the optician must have fitted hi index lenses, but she said, no, they were cr39 lenses, and it was because the frame was quite small that the lenses weren't as thick as others I'd reglazed by them.

However, I found yesterday an interesting tool which lets you put the dimensions of your chosen frame, along with your prescription, and PD, and it will tell you how thick the lenses will be with various different lens types. With CR39 lenses and this prescription, the lens thickness should be 9.7mm at the outer edge, however, it isn't even half that! Even if you select 1.74 hi index lenses, the lens thickness should be 6.7 mm. The said website is here - some of you may find this interesting for prospective purchases to see how thick the lenses will be - (for some reason it won't work in Internet Explorer so I use Mozilla Firefox).

They have fitted -9.75 lenses as I've compared it to other frames, and the edges haven't been bevelled down as you can still see the unpolished edges in their normal profile.

I just can't figure this one out, someone please help solve this mystery!

Soundmanpt 12 Nov 2010, 08:53

Kate - Not really, you should be fine with a small plastic frame and high index lenses. A few weeks ago a lady about 25 got glasses from me with an rx of -9.50 and -2.00 astigmatism correction and her glasses looked great on her. If your going for a certain look that would be more up to you.

Are you wanting myodisks?

Clare 11 Nov 2010, 15:44

Soundmanpt - when I first got glasses I was more embarrassed than anything, especially having to put them on in front of people who'd never seen them before. And I remember being horrified when an optician said at -1.50 it was worth wearing them for all distance activities (ie except reading), as I didn't think I needed to. Like you said in an earlier post today, even people with the same Rx can see differently and I just presume I have a higher tolerance than some!

Kate 11 Nov 2010, 14:08

Soundmanpt, would you recommend myodiscs for an rx of -10?

Soundmanpt 02 Nov 2010, 11:50

Clare - I do know you may not have been the best one to to use as an example. I knew you pushed back wearing correction as long as you could. But at the same time as you kinda said here you knew you probably should have been wearing full time correction sooner than you did. My guess is that besides not wanting to wear anything you got by because you could still see your computer screen good enough and any other close work. But I bet once you started wearing contacts all the time you soon found that when you had them out everything was much more blurry than before? Something you said, that when you had only -1.25 glasses you used them for driving, at the show, and watching TV. I wish I could have been a fly in your car when you first got your glasses and you had to start wearing them for driving, i'm sure you probably made some bad faces and maybe bad language as well about putting them on, but i'm sure they made you a saver driver or at least one that could see better.

I haven't seen Hollie in here for a good while, have you chatted with her lately? Hope all is well with her.

Stay well!

Clare 01 Nov 2010, 14:27

Soundmanpt - I'm the wrong person to ask I think as at that rx I was mostly without glasses, that was just before I switched to contacts. I always thought I could do okay without them so should go without, maybe that was a silly attitude but you know how ridiculous I am about wearing glasses. I wish I wasn't!

But, to answer your question, I'm sure lots of people at that rx would wear their glasses most of the time. When I was around -2.25 and -2.75 I asked my optician how much someone would generally wear glasses at that level and he said he'd expect most of the time.

Soundmanpt 31 Oct 2010, 22:09

Clare you are so right -2.00 or -2.50 is not real strong, but as you must admit at that point you really need correction most if not all the time? It seems that Alison doesn't think her glasses look strong enough, but otherwise I don't think she has much issue with wearing them full time. Sadly of course she does have the option of contacts if she decides against glasses.

Clare 31 Oct 2010, 16:28

Alison - some people will think that your prescription is strong even though you may not think so. I remember when my aunt asked to try my glasses but said she couldn't see a thing through them even though my prescription was only about -2. I didn't think it was strong before that!

Soundmanpt 30 Oct 2010, 13:36


Just what you have found, when others try your glasses they think they are strong and if they have good vision i'm sure they do seem too strong for them. Your glasses are not real strong but they are certainly well into the area of full time wear. Normally when you get past -1.50 full time wear is pretty necessary. About the only thing you may want to take your glasses off for is if your doing a lot of reading maybe. But even for that you may want to just keep them on, that is up to you. If you like your glasses and like wearing them, I see no reason to be doing the on / off thing. You will quickly find it a lot easier to just keep them on. Maybe just try wearing them full time for say the next 2 weeks and see how that works for you.

antonio 30 Oct 2010, 09:36

hi Alison,

big glasses also have thicker lenses on the sides,

and wearing metal frames, they might even stick out.

Don´t use expensive hi-index lenses as they are thinner.

Normal glass has a fraction number of 1.5

giving you the thickest lenses at any prescription.

Of course, many people wear glasses with your prescription full time already.

All the best,


Alison 30 Oct 2010, 09:01

Hi Soundmanpt,

I don't want thick glasses! I've grown up taking them off and putting them on so I guess it's become a bit of a habit. Even though they look good on me it hadn't occurred to me to just keep them on, as I can see close up I didn't think that would be necessary. So many people wear glasses nowadays but I guessed that those who wear them 25/7 have pretty bad eyesight. I guess you're saying you don't need to be blind to wear them and not take them off! That's why I thought my glasses could do with looking a kittle stronger. As they are they don't look strong at all although people who've tried them have said they are but they only make things seem a bit smaller through the lenses though some people's look more strong.

Alison 30 Oct 2010, 09:01

Hi Soundmanpt,

I don't want thick glasses! I've grown up taking them off and putting them on so I guess it's become a bit of a habit. Even though they look good on me it hadn't occurred to me to just keep them on, as I can see close up I didn't think that would be necessary. So many people wear glasses nowadays but I guessed that those who wear them 25/7 have pretty bad eyesight. I guess you're saying you don't need to be blind to wear them and not take them off! That's why I thought my glasses could do with looking a kittle stronger. As they are they don't look strong at all although people who've tried them have said they are but they only make things seem a bit smaller through the lenses though some people's look more strong.

Soundmanpt 29 Oct 2010, 15:12


Well by making your lenses a little thicker should make them appear stronger. If you are wanting more cut-in the only way you can do that is to actually order some glasses with a stronger prescription. You could easily increase your rx by about -.75 in each eye with no problem adjusting. If you choose to do that you will need to go on-line at "zenni" or one of the other retailers. Be sure to get your full rx and only change the sph in each eye. But if you just want them to look stronger making the lenses thicker should give that effect.

Is there a reason why you don't think your glasses look strong enough as they are? Your rx is certainly enough that you should be wearing them full time except maybe for close work.

Alison 29 Oct 2010, 14:37

Thanks for the replies. It's not that I particularly want my lenses to be thick I'd just rather they looked a bit stronger. I didn't know if there were types of lenses to do that?

Mr Cockeyed 28 Oct 2010, 07:59

Alison, maybe you should consider industrial 3.0mm center lenses, either in glass or plastic. Regular plastic 1.50 index lenses ground with 3.0 or 4.0 mm center thickness will be real thick, if thats what you desire

specs4ever 28 Oct 2010, 06:15

Allison, if you are in the US, the best way to get thicker lenses is to ask for regular plastic, and tell them that you need them to use as safety glasses at work. They will try to sell you on polycarbonate as safety glasses, but tell them that polycarb doesn't work for you, as they have shitty optics.(they do, but it isn't as noticible at low prescriptions). Hopefully what you will be able to get is regular CR39 with a center thickness of 3mm, and that, in a decnet size frame will give you a bit of thickness.

DWV 27 Oct 2010, 23:00

I think it was Optical4less that had pictures of massively thick lenses that were only about -2. It's just a matter of starting with a thick chunk of plastic.

Or, the stealth approach is to insist on CR39, and choose a frame with wide lenses, since thickness is proportional to the square of the radius (something like that). And ask for extra thickness for safety reasons. Or just come right out and say you want thicker lenses because you like the way they look. Make it clear that you won't complain about extra weight, and maybe they'll oblige. This may be more effective if the optician has an in-house lab.

Soundmanpt 26 Oct 2010, 15:50


Your prescription is not that weak, I would think you should be wearing your glasses full time without question. If you want your lenses to be thicker you can ask for 1.50 index lenses, it should make them a bit thicker. Also if you want them to appear thicker maybe get a semi-rimless frame that is not too small. That should show more lens thickness as well. I seem to be saying this all the time. No one really knows how much you need your glasses or don't need your glasses except you and your eye doctor. Think of this way, when you see someone in a store do you look at their glasses and think that they should not be wearing them because they don't appear to be strong? If you like wearing your glasses, put them on and wear them. As I said to start with I think most people that would even try your glasses would find them strong anyway. Your not blind but you do need your glasses.

Alison 26 Oct 2010, 13:50

I have a fairly weak prescription of -2 and -2.50. I like wearing glasses but feel they look very weak, is there a particular type of lens I should ask for so they look stronger?

Also, is it likely that people are recommended to wear their glasses fall the time they have a prescription like this?

 06 Sep 2010, 13:26

hello davey

i am anja,i m a college girl who has strong fascination for high myopia and myopes.

I would like to discuss about ur glasses by mail.pls give ur mail id or mail to my id

Mark 06 Sep 2010, 04:05


My prescription atm is -22/-21.5

Got my first myo's in late secondary school, however during college and university my jumps went up rather rapidly, ending in the -20s at the end of my degree.

went up about 0.5 per 6 months for a year and then hasnt gone up since.

Hope that helps

davey 06 Sep 2010, 03:33

hi Katy , i wear -27.50 r+l lenticular (myodisc) lenses and i have very good vision in them , although if i want to see somebodt to my side i need to turn my head towards them so i,m looking through the middle of the lenses ,if i don,t i can,t make out their faces to know who it is.Hpe this helps you.

 06 Sep 2010, 03:00

RL, hw close you have to get to answer a person who is asking to count his fingers?

RL 04 Sep 2010, 19:18


I got my first myodiscs at -13.25. I'm -15 now and I find the myos give the best vision using CR39 plastic with 30mm bowls. They are light and only 4mm thick at the edge of the bowls. What is your prescription now? I do have some full field high-index glasses, but as you said, there is some distortion at the edges. I mostly stick with the myodiscs.

Mark 04 Sep 2010, 12:19


I think about -14, at the time my eyes were a little unbalanced.

I think i was -14 / - 12.50 or something.

It was swap to myo's or keep using high index which at the time were driving me mad.

in the 20s atm though my progression seems to have stopped now.

inthecloset 04 Sep 2010, 12:10

Anyone sport glasses with CR-39 lenses? Rhetorical question how thick are your lenses having mild myopia/astigmatism? Quite Curious?

RL 03 Sep 2010, 17:14


At what prescription did you switch to myodiscs?

Mark 03 Sep 2010, 14:35

It depends on the invidivual.

Personally before them i'd had high index lenses, which had aberations at the edges, therefore my eyes were fairly used to keeping to the centre of the lenses to get the best vision. When I switched to myodiscs the area was a little smaller (I think 30mm bowls) I think it didnt take more than about 2 or 3 days to get used to them?

You end up moving your head a little more than you used to, but its not noticable to others.

Hope that helps


Katy 03 Sep 2010, 14:24

My friend has seen her optometrist again. He doesn't recommend contacts with glasses for astigmatism so she has no alternative but to go with the myodiscs. She's still not sure about how these will look but if it improves acuity that will be cool :-) Does it take a long time to adjust to myodiscs?

Mark 31 Aug 2010, 08:51

Hey Katy,

From someone who's worn them for a while:

They arent as bad as everyone makes out, in lower strengths especially what your friend has -13 region you can get nice large bowls which often are hardly noticable. They get really noticable in higher powers where you get lots of rings from the front and the bowl looks markedly different from the carrier.

If the lab tech is half decent they'll likely blend them slightly anyways.

I would tell your friend not to worry and go for the myo's, low index has far better visual acuity and its well worth using it at higher strengths.

John S 31 Aug 2010, 08:28


If she can deal with contacts, put the sphere in contacts (might be more like -11) and put the remaining astigmatism in glasses. That combination should work out well.

Katy 31 Aug 2010, 07:32

My friend has an rx of -13D. She has hi index lenses but has complained to her optometrist about the acuity with these. He fears that myodiscs are the only option. She can't wear contacts due to-1D of astigmatism. She's concerned about the appearance of the bowls but I think you can get blended lenses that look like regular lenses? Are myodiscs the best option?

The Fridge Mechanic 31 Jul 2010, 02:22

Like Lenses.

No. I fog them first, then I lick them.

Like lenses 31 Jul 2010, 00:13

The Fridge Mechanic

Do you put them in the fridge first to get them frosted over, and then treat them as a popsicle?

Daniel 30 Jul 2010, 21:07

I was not aware of the flat lenses either Yasmin, it caught my attention how much light they reflected, and then after reading some post in here I realized why they were flat.

The Fridge Mechanic 30 Jul 2010, 20:02

Large flat-fronted high myopic lenses are the best. How I love to lick them.

Yasmin 28 Jul 2010, 18:32

Hi Daniel,

my current glasses have flat fronts, too (-7/-6). They are just 45 mm wide, so the wideness of the lens should not be the reason for flat fronts. I chose 1.74 high index lenses and highest possible AR coating. In my case it shimmers light green. Before I read this here on eye sceene, I never noticed that my lenses were flat. I guess most "normal" people wont tell the difference. Every lense reflects the light from a stupid angle.

Hi Like lenses,

I have no problem to see my eyes in the mirror from the back of my bathroom (~ 6.6 feet). Then I tried to see my eyes from the back of my living room but not the reflections but my poor correction restricts to see my eyes clearly.

Daniel 27 Jul 2010, 15:15

I am not sure about the distance but I would say that most of the time all I can see is light reflecting on them. Honestly a feel a lot more self conscious about my glasses than ever before. I guess I should have know beter and paid for the more expensive lenses. I am usually a full time contacts wearer but recently I´ve had to give my eyes a break more often than before.

Cactus Jack 27 Jul 2010, 02:07

The power of a lens is determined by the difference in curvature between the front and back surface and its index of refraction of the lens material. The glasses fashion these days is the thinnest possible lenses using high index materials. The result is that it doesn't take much curvature to get the power needed in a thin minus lens with a flat or nearly flat front, or a thin plus lens with a flat or nearly flat back surface. The side "benefit" is that the lens has very thin edges compared to say CR-39 and the customer will pay more.

I have never heard of there being a relationship between height of fashion and magnitude of the price (and profit). Amazing!

BTW, lenses with flat surfaces really need a good AR coating to reduce the very distracting reflections from the flat surface.


Like lenses 27 Jul 2010, 01:24

I am curious . When looking in a mirror at yourself with minus glasses on , at what distance can you no longer see your own eyes clearly due to the lense thickness,and reflections.

I am -5.50 and can see my eyes at about three feet, but not at four.

Like lenses 27 Jul 2010, 01:18


I think that newer lense technology is having weaker lenses with flat front base curves. It used to be that they became flat at -9.00,but I have a friend that is -3.00,and her newest pair are flat front.

I wear -5.50 and have had mine made with flat fronts since I was -1.25. I like that look and they use higher power blanks,which result in thicker glasses.

Daniel 26 Jul 2010, 12:23

I picked up my new glasses from the eye doctor at a well kown convenient store yesterday´s afternoon, and to my suprise they had flat front lenses. I´m just -7.50, though my frames are a little bit oversized, would that be the reason the lenses are flat?

Ryan O'C 13 Jul 2010, 10:20

My sister and I got flat front lenses when were about -8 or -9, about 8 years ago. They coincided with our first bifocals. Always have had AR coating.

RL 09 Jul 2010, 16:18


I got my first flat front lenses at -11. That was in the eighties and the frames were pretty big and the lenses were CR39 plastic and were over a half inch thick at the outer edges. When my prescription reached -12, I went to the myodiscs so I could stay with the CR39 which has the least abberations of any of the lens materials.

RL 09 Jul 2010, 16:13


I have -15 myodiscs with flat (plano) fronts. I find they give the very best vision of any lens for me. I have had biconcave lenses, but there is alot of distortion around the edges and they stick out of the frame in the front. I have a pair of biconcaves where the prescription is pretty much split between the front and back curves. Probably -7 on the front and -8 on the back. They're still nearly 12mm thick and look pretty radical. I like the myodiscs much better and they give better vision. The flat fronts do reflect light, but you can get anti-reflective coatings to minimize the effect. The myodiscs have 30mm bowls and a +6 carrier so they make the edges of my face look big in contrast to my eyes which look really small.

myofan 09 Jul 2010, 15:07

I've always wondered what it's like for a high myope to receive his/her first flat-front lenses. The reflections are obviously very different from lenses with a positive curve, but I'm curious about any other changes as well. I'd imagine that after a while, the plano fronts just become a fact of life and don't cause any continuing concern. Would someone with experience give me a clue how this works?

Ryan O'C 05 Jul 2010, 08:23

To those who asked:

I do not have bi or trifocals in the myos, the myos are flat front and I use clip-ons for trifocals with a plano top, +2 intermediate and +4 reading segment.

I don't know where my glasses are made as we go through the optical department of a teaching hospital and they send them out, it takes about 6 weeks.

My corrected VA runs about 20/30-40.

My sister also has high astigmatism and wears glasses over her contacts with the cylinder and add.

Cactus Jack 04 Jul 2010, 18:08


I'm glad you posted. I was thinking of your situation when I asked for a private contact. I would think if the front surface of the myodisc lens was flat, it might be possible to have a bifocal or trifocal blank and grind the bowl with the sphere and the cylinder into the rear surface. Perhaps Soundmanpt who has some experience in making lenses could comment on the practical aspects of making a myodisc lens with prism, high cylinder and bi or tri-focals. I would have to believe that the PD, adjusted for the prism correction would have to be "dead-on" to not have severe effects on acuity. This gets back to my curiosity about combining high minus sphere contacts with glasses which have the rest of the Rx. This might provide the best possible acuity and minimize glasses induced distortion and image size reduction caused by vertex distance effects in high minus Rx glasses.


Puffin 04 Jul 2010, 17:48

Ryan O'C

That's quite high astigmatism, does correcting it affect acuity? Seen some cases where it does.

Brian-16 04 Jul 2010, 17:48

Ryan O'C -I did not know you could get an add (bi-focal) in myodisks.

Cactus Jack 04 Jul 2010, 16:04

Ryan O'C,

Please contact me at I would like to ask you some questions about your acuity with your glasses and who made them for you.

I am a bit surprised that you could get myodiscs made with your Rx. There are occasional questions about myodiscs and perhaps we can help some others with similar needs.


Ryan O'C 04 Jul 2010, 12:12

Just got my first myodisks at -20. The full Rx is R -20.0 -6.5 x25 15BO L -19.5 -6.25 x40 15BO add +3.50. I have a twin sister who is about -17 with no prisms. I think she is interested in myos also because my glasses are now so much thinner, although she mostly wears contacts. Double digit myopia runs in the family.

My sister and I will be starting college in the Fall.

Emma 08 Jun 2010, 11:28

post deleted - troll

Rayray 07 Jun 2010, 12:42

Emma any chance you could tell me what was the lowest rx you got myos at?

Lee 07 Jun 2010, 12:18

Post deleted - troll

Wei 03 Jun 2010, 08:35

Yes wide plastic side very nice. But of wooden better i think!

ehpc 03 Jun 2010, 08:20

1980s is my era. Although many of the trendy rectangular plastic frames with wide sides available now are even hotter. Black is the best, but bold colours like red, dark blue, and purple can also be very hot.

Wei 03 Jun 2010, 08:00

Many lens for lenticular, is carrier plano! So yes is mysodisc. Frame wooden. No termite.

Astra 02 Jun 2010, 21:24


Pete should have optical store like that if it is now 1960s or 1970s... Such frame should be widely popular back then.

ehpc 02 Jun 2010, 19:52

Cool :) I shall really look forward to that :) Pete

Heather 02 Jun 2010, 19:31

ehpc - When I don't need the old frames as backup glasses any more, I am going to donate them to you ... :)

Soundmanpt 02 Jun 2010, 19:15

ehpc - If you had an optical shop you would only sell one frame style - big rectangle black frame with wide arms. Your store would be small, very small.

ehpc 02 Jun 2010, 19:07

The thick lenses and the big black rectangular plastic frames with wide sides must have looked SO hot..............:)

Heather 02 Jun 2010, 18:10

Charles - Thanks. I was just interested. Luckily I don't need any myodisks. I just got new high index lenses (1.74 index) which are just great. They are so thin even for a -5.00 prescription. Before that I had Polycarbonate lenses (also with a slightly larger frame) and I found them horrible because of the thickness of the lenses.

scott 01 Jun 2010, 11:28

Hi; I was collecting a new box of contact lenses this afternoon but i was trying to listen to a conversation that the optician was having with a customer. She (optician) was asking the female customer what type of lenses did she want. The choice was blended lenticular or semi-lenticular. The customer was baffled about semi-lenticulars saying that "ive always had blended lenticular lenses". I couldn't stay any longer to listen to what a "semi-lenticular" lens is like.

any ideas?

Charles 31 May 2010, 23:05


When I was first prescribed lenticular lenses (nyodiscs)I was told that I would find them lighter, thinner, possibly better looking in some respects and, above all, better optically. All these things, with the possible exception of appearance, were true. I found the optical improvement more than compensated for the unusual appearance and also the notional decrease in peripheral vision. I say 'notional' because with normal glasses my peripheral vision was so distorted as to be of little use. As well as standard lenticulars, I also have the blended type. These are certainly better looking but I seldom wear them as I find them less good to wear, particularly at the periphery.

ehpc 30 May 2010, 11:30

Emma - blended myodiscs for are just the hottest glasses a girl can wear :) Pete

Puffin 30 May 2010, 10:11


Yep. If you take an ordinary plus lens, turn it round so that it sticks out towards the eye, then scoop out enough of the lens to make a minus corrective lens, you'll find you can get more power for a given thickness and it will be nearer the eye. The closer to the eye it is the less minification you get. Anything over -25 will give significant minification and will be ridiculously thick unless you do this. Remember also that people with this level of myopia often have acuity problems thanks to the high curvature (and thus stretching) of their retinas, among other reasons, so image size becomes even more important.

Okay, perhaps the lens will look a bit odd, but then any other glasses-based solution will look just as odd and probably have less good corrected acuity.

Heather 30 May 2010, 08:20

So are myodisks also used to get better clarity rather than just to make the lenses thinner?

Emma 30 May 2010, 06:49

Oh yes, it's money well spent. I have some blended and unblended myodiscs. The blended ones just look like normal lenses but lighter and thinner, so no one can tell they are myodiscs really.

Wei 29 May 2010, 11:59

I think of mysodisc for lens very good!

LikeGlass 28 May 2010, 19:08

Found this interesting. Apparently, as we know, AR coatings can go bad. Here is a girl that found you can remove the coating using Armor-etch and end up with the lenses looking a whole lot better! (don't rub it.) Anyway, I know the topic of AR coatings going bad has come up before and this looks like a great way to salvage the glasses as compared to spending a ton of money on new ones. It's a flickr site, just browse through the pictures as she shows how it went.

Interested 28 May 2010, 03:10

Emma what is your rx and is your optician right. Was it money well spent. What was the reaction when you first wore then yourself and any comments from your friends. I am tempted but could you kindly expand a little. Thanks

Emma 28 May 2010, 02:52

I have myodiscs in a lower RX. I've been told you can get them from -6. Which seems low my new optometrist recommends them in lower RXs for better acuity.

Heather 27 May 2010, 14:34

RL - Thanks for your answer.

Wei 27 May 2010, 00:06

Yes i have mysodisc! Is lens good -18d! So of friend is -7 and have mysodisc for vision very good

ehpc 26 May 2010, 17:57

You are very gracious, Heather.A strong woman indeed..........except for her dependence on 'strong glasses'..............:) Cool :)Pete

Heather 26 May 2010, 16:35

Mr T - Wow, the boss has spoken! You seem to be quite the authority over here. No wonder given that you are so smart to know all these things!

Mr T 26 May 2010, 16:10

regarding Heather; You need to come out of your closet. Stop playing us with the "innocent" questions, you already know the answers. You're obviously an OO, just like most of us here. We admit to that, but you're going further, you're just somehow gettin' off on playing the role of being some "victim" of myopia, (and not even severe myopia) which is coming off to me as really disrespectful. Tons of people have myopia just like yours and even more, and never think twice about it. Get real.

RL 26 May 2010, 16:08

Heather, I have heard they can be made in any prescription over -6 but that would be unnecessary. I got my first ones at -12 because I wanted CR39 plastic because it has the fewest abberations and gives the best vision (I think.)They seem to work best for prescriptions above -14 or -15. I'm -15 and think they work better than any of my other glasses. They are much lighter than the high-index lenses and fit nice and close to my eyes.

Heather 26 May 2010, 13:56

Regarding myodisks, what is actually the weakest prescription they are used for? Just wondering.

RL 26 May 2010, 13:43

Just wondering if there are any other myodisc wearers that visit this site. Not GOC, but really needing the myodisc lens. If so, at what prescription did you get your first pair?

Aubrac 26 May 2010, 06:09

Cactus Jack

The article was in the Health Section of the UK Daily Mail yesterday. I'm not certain if there was a reference to astigmatism correction but I'll see if I can find a copy.

One of the drawbacks for the average person was a waiting period of two to four weeks before any tuning of the lens could be done. During this time, and during the week light tuning was carried out, wraparound dark glasses had to be worn all the time (even in the shower) to prevent any UV light triggering a change in the implanted lens.

Not a viable option for most of us to be virtually unable to function or work for five weeks, however does certainly open up some interesting possibilities.

Cactus Jack 26 May 2010, 04:38


Interesting and certainly possible. I have not heard of these lenses being tested or available in the US (our FDA bureaucrats are not usually in a hurry to approve any new treatments for anything. Better safe (for them) than sorry!). I wonder if there is a way in the light adjustable lens to correct astigmatism.

The idea is potentially a good one, but I think I would not be in any particular hurry to try the lenses. More than half of the effort in triggering the developing new ideas and products is to show that there is solution to a problem. If these lenses show that IOL lens power can be successfully and permanently adjusted by light, other improvements and innovations will follow with amazing speed.

Light adjustable sphere power might be very helpful, but what would be fantastic would be a flexible lens that truly replaces a presbyotic (hows that for a word?) crystaline lens. Then, all that would be necessary is to re-condition the ciliary muscles and presbyopia would be cured.

I wonder if the light adjustable lenses can be adjusted to correct astigmatism?


Aubrac 26 May 2010, 03:53

Don't know if this is the right thread but was reading in the paper yesterday about Light Adjustable Lenses (LAL).

These are new in the UK but may have been around a while in the US. They are inserted into the eye like a replacement lens following cataract surgery, but can be used at any time if £9,000 is paid.

It seems that the lenses are tuned over a period of several days by specific light intensities that adjust the lens for perfect distance and close vision. A brighter light is then shone which fixes the prescription.

A women in her sixties described the process and claims to now to have perfect vision at all distances.

ehpc 24 May 2010, 19:06

Minus 4 or 5 just isn't 'strong', Heather. Not at all.

RL 24 May 2010, 17:33

Heather-I never got into myodiscs until I reached -12, and that was probably a bit early but I really like the thinness of that kind of lens. The little circles in the middle of the lens with the plus carrier around them are certainly different to look at, but since I'm pretty much stuck with them I've decided they're sort of exotic and cool.

But at -5 or -6 you're a long way from needing anything like a myodisc.

Heather 24 May 2010, 16:40

RL - Glad to hear you are getting along well with the myodisks. I certainly hope that -5.00 or -6.00 is going to be the end of the line for me. Like you I had to give up contacts since I did not tolerate them any more. I am still trying to get used to having to wear strong lenses all the time.

RL 24 May 2010, 16:16

Heather, It really isn't so bad. I have 20/20 vision in both eyes and have never had any pathological problems like detached retinas etc. With the myodisc lenses that I described the thickest part of the lens at the edge of the bowl is only 5mm; the outer edge maybe 2mm. The CR39 plastic gives the best vision as far as I'm concerned. I have some high index lenses that are full field and are about 9mm thick at the outer edges, but they do have some abberations at the edges. I wore contacts for a long time but got so I couldn't tolerate them and went back to glasses. I think I was -5 by the time I was 16 and it went up from there pretty steadily.

Heather 24 May 2010, 13:32

RL - I am really not sure how you survive with such a presctiption and regular plastic lenses. I already have trouble with a -5.00 prescription, which seems very strong to me.

RL 24 May 2010, 13:10

Just picked up my new glasses. They are myodiscs made in CR39. Turned out very cool: 30mm bowls, +6 carrier, and plano fronts. The edges of the lenses are thinner than the frame which is good since in a full field lens my glasses are about 16mm thick at the edges. Tehy do magnify the edges of my face alot which makes for quite a contrast with the really small eye size through the bowls. They are very light and comfortable for -15.

Tim 22 May 2010, 21:26

Also the fronts were not (quite) plano.

Tim 22 May 2010, 21:22

Have the Chinese come up with some new superhigh-index lens material? I saw a Chinese girl yesterday wearing a pair of glasses with thin wire rims. The cut-in and minification from the lenses suggested about -12 to me, but there were no visible power rings and the lenses barely protruded beyond the frame either in front or behind - they cannot have been more than 2 or 3mm thick at the edges!

Stingray 18 May 2010, 10:13

Dee: My cousin in an optician and he uses toothpaste and a cloth to take out the superficial scratches. I would try it first on an old pair of glasses first, you don't know what kind of grit is in a particular brand of toothpaste, so go easy.

Dee 18 May 2010, 02:06

I noticed my new glasses already have a small scratch or chip in the corner of one lense. When I was younger there was a polish or something that would fill these that my eye doc gave me. Is this still true?

Charles 15 May 2010, 23:03

Sorr.y, I forgot to add my name to that post

Cactus Jack 15 May 2010, 23:01

I think I have tried all types of lenticular lenses (myodiscs)including blended. Blended certainly look best but, somehow, I have never felt comfortable with the smooth, blended edge of the bowl which even more than the standard type which are set in a plus carrier. When my eyes strayed from the bowl the effect was quite disconcerting! a few years ago, I switched to a plano carrier which is excellent. The carrier is very, very thin and the 18mm bowl is set very close to my eyes which means that I have to really try to get my eyes to stray over the edge. When they were first fitted, my eyelashes touched to bowls and the dispensing optician, with great care, had to cut them. They have never grown back! The optical effect of having the bowl very close to my eyes is excellent as the minification effect is slightly reduced which is helpful to my acuity. Very importantly, they are the lightest lenses I have ever had.

Lunettes 15 May 2010, 22:24


What is max diameter of hi index lenses.

These new large eyeglasses ans specially sunglasses,can they be fitted hi index tinted,polarized lenses.

rx is about -4,5.

Cactus Jack 12 May 2010, 20:15


The language differences make it very difficult to understand your questions in English. I would suggest you do a search on Blended myodisc lenses and study several of the suggested results. I found the discussion at OptiCampus to be very informative. However, you need to be aware that some of the illustrations are displaced from the related text.

I don't know if you are doing the English to Chinese and Chinese to English yourself or doing it with a translation program. Ideally, you should read and understand the discussion in its native language, English. It gets rather technical. The section on various types of myodisc lenses is about 3/4 of the way through the discussion. I have no experience with myocisc lenses, but it appears to me, that the various types of myodisc lenses primarily differ in the optical effects when the eye strays outside the bowl. The blended myodisc lenses provide the best appearance to others, but appear to provide little benefit to the wearer because the area of the lens outside the bowl is essentially useless to the person requiring myocisc levels of correction.

Perhaps some of our experienced wearers can comment.


Dave 10 Dec 2009, 12:14


Glad you got your glasses sorted out. I've noticed that plano (flat-fronted) lenses are becoming the norm with many rimless glasses' prescriptions, even fairly low ones. I think the objective is to make them as thin as possible since there isn't a frame to hide the lens thickness. The tradeoff is the flat front lens usually associated with prescriptions -9 and higher.

guest 10 Dec 2009, 09:25

I took them back to the opticians and complained about the workmanship, there was also a tiny chip on the edge of one lens. They still insisted that it wasn't possible to get minus lens with a curved front face in my prescription. They did offer to replace tthe lens with the chip and they said they could "flatten" the curvature of the top of the frame to accommodate a flat lens. I decided to go along with it as the best option although I wasn't convinced.

Today I collected them as they did them really quick. They are much better, the neww lens are now much more recessed into the frame with all the thickness to the rear. They have also flattened the frame profile to suit the flat lens. They do look 100% better but I still think they look terrible with flat lens. I intend to get them done again sometime when I can afford it at another opticians. Next time I will be very specific about what I want and expect!

thanks for your comments.

guest 09 Dec 2009, 04:06

OK, thanks Hollie, I'm sure they could have made them with some nicer looking lens and better attention to detail with the glazing. These are semi-rimless frames. there is no prism in my prescription, I think it's just that there is some curvature in the frames that doesn't suit the flat lens so they are OK in the middle but stick out of the front near the nose pads and at the outer edge. I dont mind about the thickness of the lens at the outer edge which is 6 or 7mm, they are polished and look nice, in fact I prefer a thicker lens, it would just be a lot better if it was all to the rear of the frame and with a lens with a curved front.

I don't think I'm going to get anywhere wit Specsavers, I think I'll have to get them re-glazed elsewhere andpay again. If I do I'll certainly explain what I want and ask if they can do them exactly as I requested.


Hollie 08 Dec 2009, 23:42


I have a similar prescription to you, got my glasses at specsavers and they are not flat. However I agree with you the workmanship can be poor. I took a pair of plastic framed ones in for tightening and they said the lenses were set too far forward and were in danger of falling out! They adjusted them for me, but another branch of specsavers had made them in the first place!

nostolgic 08 Dec 2009, 20:38


If you have any prism in your lenses (you didn't say you do), aberrations are reduced by having flat front lenses. e.g., your vision will be better.

Some online sites (I think optical4less and 39dollarglasses?) will 'reglaze' (put new lenses in your frames you send in) for you for a reasonable amount.

If you can order from them, that is!

Guest 08 Dec 2009, 16:06

They were very insistant that they could only supply flat fronted lens in my prescription. I thought this was wrong but they insisted that it was fact. The lens were standard CR39 with AR coating. Maybe I'll have to go elsewhere for a better job. Unfortunately I dont have my old lens to show them what I'm after. Maybe it's down to the cost, the lens were £39 + £30 for the AR coat, total £69 which I thought was not very expensive (this was Specsavers). The worksmanship was terrible, looked like they were rushed and they didn't really care how badly the lens fitted my frame.

Puffin 08 Dec 2009, 13:51

Guest: that is nonsense. flat (plano) fronts normally start these days at about -9 or possibly a bit more if you get the right lens material. Your optician should have no big problem sorting out non-flat lenses if you want them for your prescription.

Guido 08 Dec 2009, 10:18

I had a similar experience several years ago with a script similar to yours. The lenses were very flat and reflected quite a bit. People remarked about how strong the new glasses appeared. The Optician swapped them with lense with a convex base curve. If you have old glasses with your previous script, take them in and have them measure the base curve (front curve of the lens) and have them duplicate that curve. It is a solvable problem, just be persistent!

guest 08 Dec 2009, 09:39

I just got some new lens in my frames, -6.50, +1.00 both eyes. I was very disappointed with the result when I saw them on collection, they have fitted lens that were absolutely flat on the front and even with the anti-reflection coat they look dreadful. The lens sticks out at the front corners of the frame.

I took them back to the opticians and complained, I said I wanted lens that were more curved on the front but they said it was impossible, minus lens cant be made like that. Is this true, I'm sure that previous lens I've had have not been so flat and looked much better.


A.D. 01 Nov 2009, 15:18

Thanks for the answers! I'll have them replaced...

DWV 30 Oct 2009, 01:01

I, Glasses:

Well, partly personal experience; I've ordered a couple of different types of bifocals in glass and plastic. And, reading what technical info I could find in books or online. Some useful texts can be browsed with Google Books. I think one was "Ophthalmic Optics". I found an online introductory course for wannabe opticians, and Marchon had some free online courses on lenses.

The lens "sag" formula is useful for estimating the thickness of segments. The key fact is that thickness is proportional to the square of size, so going for a wider segment means a thicker "ledge", or a wider lens makes for thicker edges in a minus lens. 41% wider means double the thickness, so if you want "spectacular" lenses, choose a huge frame and the widest possible bi or trifocal segment.

Melyssa 29 Oct 2009, 12:48

I've had many of the lenses of my pretty plastic pairs of glasses replaced over the years, mostly when my RX was changing. Only once did a frame break, and that was on the side of the frame near the temple, which was rather unexpected.

Puffin 28 Oct 2009, 17:27

I've found during my experiences of fiddling around with frames and lenses, that metal frames are easier to replace the lenses in, just undo the screws and there you go. With plastic frames I heated them a little to expand them and make them more pliable. Unfortunately they sometimes don't like this and break.

The flip side to this is that if you've got advancing myopia, metal frames are obviously less good at hiding extra thickness.

A. D. 28 Oct 2009, 17:00


Over the years I've accumulated a number of glasses, including plastic, rimless and semi rimless frames. Since my prescription increased, instead of buying a new pair(s), I'd rather replace the lenses in some of the existing ones.

Is it possible to do it for all kinds of frames?

I, Glasses 18 Oct 2009, 10:17


I appreciate your answering my post, and I thank you for your advice. I'm curious, though -- how do you know those details so well?

DWV 13 Oct 2009, 14:41

Regarding your previous post about how to maximize thickness... AFAIK CR39 is the lowest index available.

If you went with lined multifocals, there's a couple of options that would increase thickness:

1) Glass bi or trifocals. Since the segments are embedded in the lens right where the lens wants to be thinnest, the lens has to be made thicker. Bonus: the segments are virtually invisible, except if the light strikes them just right, and the transition between segments is cleaner than with plastic lenses. The downside: heavier, and maybe not the best choice for rimless frames.

2) Executive bi or trifocals. Probably a bigger gain in thickness, although it would be more pronounced with a plus lens. Not virtually invisible, although since the "ledge" is on the underside, it doesn't catch the light as well as the segments on plastic FT multifocals.

Maybe just being honest and saying you _want_ thick lenses because they look cool will convince the optician/sales-critter to instruct the lab to go for broke. The lab rats may enjoy a chance from the usual.

I, Glasses 13 Oct 2009, 12:48

Interesting plot twist on 'CSI Miami' last night. While investigating a murder scene, police found a contact lens. A suspect wore glasses, so the police, on their lensometer, checked his glasses Rx against that of the contact. No match; he was cleared. Ultimately, the real culprit was in police custody for questioning. Asked if he wore contacts, he said yes, and the detective asked him to remove one. He did, the policeman compared the two prescriptions, they matched, and the man was arrested. His prescription, announced by the detective -- minus 7.5.

minus 5 who luvs gwgs 10 Oct 2009, 22:47

I posted yesterday on post my prescription forgot to mention my gf s new lenses The shop tried to push thinner lenses saying how thick they would be and the standard ones were CR39 so I suggested these and they have come out about half an inch thick and look lovely

I, Glasses 28 Sep 2009, 12:37

I wear roundish wire-rims with my actual Rx, minus 4, with progressive adds for near and intermediate vision. I’ve had a change in prescription (not in sphere, but a total disappearance of astigmatism) and I need new glasses. I’d like to get the traditional-shaped (‘octagonal’) rimless with lens edge thickness that is noticeable, but not quite as thick as some larger aviators I used to have (Rx minus 6, 55mm vertical, 55 mm horizontal, 14mm bridge, and a 9mm edge thickness).

Each of my current lenses is 40 mm vertical and 45 mm horizontal, and the bridge is 20 mm wide; the edges are not polished, since they’re beveled to fit in a frame, but I measure them at 5 mm thick. I’d like the lenses in my new rimless glasses to be somewhat thicker than that, but not quite as thick as the 9mm lenses in my seventies glasses.

With that in mind, what option, or combination of options, should I pursue?

Actual prescription, or greater (If greater, wouldn’t the adds need to be greater, too, to make up for the additional minus?)

Same size lenses as current, or somewhat larger?

Lowest index available (is that still CR-39?)?

Maximum center thickness (Industrial strength?)?

Base curve that results in maximum thickness (but without distorted vision)?

Polished edges?

Any other option(s)?

Finally, once I have determined the best techniques to get the thicker lenses, is there some way I can get a fairly accurate estimate of the edge thickness before ordering the

glasses, based on the prescription, the size of the lenses, and the other criteria mentioned above.

VisitBoy 14 Aug 2009, 05:03

Thanks Cactus Jack for your advice. :-)

Cactus jack 12 Aug 2009, 05:21


Probably none.


VisitBoy 12 Aug 2009, 01:46

Thanks Cactus Jack for advice. I wonder if you'd say what the potential problems are with inducing BO prism by reducing PD, especially if only by 2mm per eye.

Cactus Jack 11 Aug 2009, 05:38


I was not very clear on de-centering for prism. Decreasing the PD has the effect of inducing Base Out prism and Increasing the PD has the effect of inducing Base In prism.

A diopter of prism deflects a ray of light about 0.5 angular degrees and up to about 5 diopters of prism is almost unnoticeable other than an increase in edge thickness of either the inner edge for Base In or outer edge for Base Out.

If you plan to order on line, it is better to order from someone that offers prism and let them do the de-centering calculations Optical 4 Less and Eyeglass Factory Outlet both offer to make glasses with prism and apparently know how to do it.

Please remember that Base Out prism is used to cause or correct excessive convergence and Base In prism is for divergence.


VisitBoy 11 Aug 2009, 01:56

Thanks for your reply, Cactus Jack.

I actually know my PD from previous measurments for glasses. I want to adjust it for a bit of base-in, but keep it within a normal range to avoid rousing suspicion. Why do you say this is not a good way to get prism?

I'm looking at lenses about -4

Cactus Jack 10 Aug 2009, 13:35


Sometimes there are very simple solutions to really annoying vision problems. Hang on to that 6th doctor. He/she is a rare jewell who actually looks at and listens to the patient. They are very hard to find.


Buck 10 Aug 2009, 13:26

For what it's worth I had a major problem where the vision in my left eye would go from moderately farsighted in the a.m. (normal) to quite nearsighted by late afternoon (or earlier). One eye only. Two opthalmalogists and 4 optomitrists dismissed me, one saying I just need 5 or 6 pairs of glasses to change throughout the day. The 6th Dr. actually looked at me instead of notes while we spoke and said, "I think I see your prob. You have dry eye and your left eyelid does not close properly. Apparently the dryness along with a scratch in my cornea made the shape change as dryness increased. Tear drops fixed all and a change of meds that stopped dry eye.

Cactus Jack 10 Aug 2009, 13:02


Your actual PD is very easy to measure and that is where you start. All you need is a ruler marked in mm and a bathroom mirror.

All you need to do is measure the distance from the center of your nose to the center of each pupil and add them together. Do this 3 times and average the result. It will probably be in the 60 to 70 mm range, but can vary, which is why you measure it.

Once you have that number, you can adjust it downward for Base Out prism. It is approximately 0.27 mm per prism diopter, but it varies slightly depending on the Rx.

This, by the way, is not a good way to get prism in your glasses. What is your current Rx and how much prism are you thinking about.


VisitBoy 10 Aug 2009, 11:28

I wonder if anyone - perhaps Cactus Jack - would advise me please: What is the normal range of Pupillary Distance (PD)? I'd like to decrease this on my Rx in order to induce a little prism.

Secondly, approximately how much prism would I induce for each millimetre I subtract from my PD? I'm sure this has been discussed before, but I haven't found the discussion again.


Trent 09 Aug 2009, 18:14

Cactus Jack

I had my fasting blood sugar done and it was normal. I think my change has more to do with eye strain as the changes are slight but noticeable. Thanks for your concern though.

Cactus Jack 09 Aug 2009, 06:44


I have not been following your discussion with Danbert very closely, but depending on a number of factors, changing Rx during the day can be caused by unstable blood glucose levels. Changing blood glucose levels cause the refractive index of the vitreous humor inside your eye and the aqueous humor between the cornea and the crystaline lens to change. The result is changes in your Rx.

Typically, changes in blood glucose levels are an early symptom of diabetes or uncontrolled diabetes in those who have it.

Today, diabetes is relatively easy to manage and uncontrolled blood glucose levels can do a lot of damage to your eyes (retinal and cataracts) and other vital organs in the body.

If you have not done so, I strongly suggest that you investigate the cause of your changing Rx and get a test for short term blood glucose levels (involves only a finger stick) and if indicated a long term blood glucose A1c test (which involves a larger sample).

I discovered that I had Type 2 diabetes on a routine physical when I was about 30 and I have been managing it closely for 40 years. So far, no retinal damage and with correction, I can get pretty close to 20/15.


Trent 07 Aug 2009, 20:03


Thanks for the answer. Yes I have also heard that the power range of the silicone injection eyeglasses is only -6d and there is no cylinder correction. Being -8d with a high cyl, I do not believe these would work for me. I would need a base lens containing most of my Rx. I am still interested in the TruFocals even though they make no fashion statement.

Danbert 07 Aug 2009, 09:38

@Trent: The last line should read "I don't see a reason why a hyperopic type could not be manufactured."

Danbert 07 Aug 2009, 09:37


I am sorry that I didn't actually answer your questions.

If your Rx changes only several times during the day, then perhaps they would be a good solution. As an emmetrope I lack experience in that area, but I don't know if it wouldn't be just as easy to swap glasses a few times a day...

As for the range, I read elsewhere that they are being manufactured with a range of 0.00 to -6.00 diopters. They are intended for myopia and not hyperopia though I don't see a reason why a hyperopic type could be manufactured.

Danbert 07 Aug 2009, 09:33


Essentially the same technology was in the news only a few weeks ago, but intended for export to places in the world where there are insufficient opticians (and money) to do things the way they are done in the "developed" world.

That one was posted a while ago somewhere here but in case you missed it:

Apparently they're selling them for $19 overseas. You wouldn't get a price like that at your local optician though.

I think they're a great idea in developing countries where people simply cannot afford the eye care that you and I take for granted, especially for children where their Rx would be changing quite often.

I am honestly a bit dubious about using them in place of bi/tri/varifocals though:

1. People care about appearances, and it is doubtful that they will look "fashionable."

2. They require constant manual adjustment, which is really not a very natural way to view the world at all.

Until technology is available to autodetect the required focal length, I do not see this taking off as a solution to presbyopia.

I'm not sure how much these ones differ from the similar product

Trent 05 Aug 2009, 18:15


Because my vision changes throughout the day I found this to be an interesting concept. Any idea of cost and what the change to the Rx is limited to?

Danbert 05 Aug 2009, 01:01

Nova man 26 Jul 2009, 08:42

I dont know if this is the right thread of I should put this in sightings. I saw a friend of mine the other day and she has worn glasses for a long time. I notice she had gotten some new frames. I didnt have time to chat with her but what I noticed right off was , I remember her old pair and her lenses somewhat thick with the right being worse than the left and the lenses were almost flat on the front, well this pair was really thin and the lenses were not flat, curved like a low rx?? any Ideas. why is it the lenses are flat anyhow, My wife needs a new rx she is a minus 7 and her lenses are flat is there any type of lense she can get that wont be flat on the fronts

Mark 16 Jul 2009, 12:00


There are lenses on ebay which i saw recently from an american shop with high plus lenses with very high prism.

American vision or something like that was the ship name.

Astra 16 Jul 2009, 11:07

When lenses are under bright light conditions, does the size or shape of the shadow of the lenses itself reveals some clue about the prescription?

For example:

Katy 15 Jul 2009, 10:10

Actually this one might be better, as it is for slides so focusses closer:

Katy 15 Jul 2009, 10:04

Biggles - you can buy viewers that have the lenses already in, to view images at about 5cm:

These are for pairs of images so you can view them in 3D, and you can buy an attachment for your camera to take the pairs of images. Might be a cheap way of getting the lenses even if you didn't want to use the viewer as it is.

OttO 15 Jul 2009, 09:25

I remember those View Masters from when I was a kid in the 1950s. I had one. Really neat. Mine showed tourist sights around Chicago. I think you could even change programs. Today it might be possible to locate them either on Ebay or perhaps in antique stores.

Cactus Jack 15 Jul 2009, 07:50


The first sentence of my post should read . . . without some prism help.


Cactus Jack 15 Jul 2009, 07:49


To focus comfortably at 5 to 6 cm, you would need lenses in the +16 to +20 range, but it might be hard to converge enough to have comfortable vision at that distance with some prism help.

There are vision aids made for close work that might be useful. They have high plus lenses with prism to help focus close and also converge. They are marketed for hobbyists and others. I suggest searching on the web for "Close Work Glasses" or similar topics.

Many years ago, around the 1900s, there was a device made for viewing 3D images called the Stereopticon. It came with cards that had two pictures made with a special camera to give a 3D effect similar to the ViewMaster device marketed in the 1950s for viewing 3D color slides.


Biggles 15 Jul 2009, 06:30

Hi, Cactus Jack!

I posted a question in lense chat and skipp suggested I direct it to you.

I'm looking to build a gadget and one of the problems I'm facing can be rearranged to be like the following:

Imagine that I were to put a small postcard in front of your eyes, say 5-6 cm away. What sort of lense could I use between you and the postcard to make it look as if the image is actually at a much greater distance? That is, your eyes would not strain to focus on it and the brain would be tricked into thinking that it could see a beautiful landscape.

I'm guessing that such a lense exists? are they hard to come by?

Many thanks!


Rachel J 13 Jun 2009, 22:58

And. She must see what I do without glasses then. Virtually nothing except really blurred unless its very close

And 13 Jun 2009, 17:16

Ha, sorry, she posted earlier and you have the same rx, it was probably a daft question anyway.

Rachel J 13 Jun 2009, 09:21

And. I don't know what the other Rachel's scrip is do I

And 13 Jun 2009, 04:36

Sorry Rachel J, I meant would you and the other Rachel have identical views of the world because you have the same script.

Rachel J 13 Jun 2009, 03:00

And. Well my rx isn't all that different for each eye. I only have -0.75 stonger in my left eye so if I'm without glasses my eyes are still fairly balanced. All the same if I'm reading in bed after I've taken my glasses off I usually close my left eye and just read close up with my right eye, because that is the best eye. I think lots of very myopic people do that. When I've noticed my auntie ever take her glasses of, she does the same.

And 13 Jun 2009, 02:21

Racel/Rachel J - same script, sorry I'm getting confusd who is who so apologies if I'm duplicating questions. If you were both bare-eyed would you 'see' exactly the same or do different eyes kinda cope differently ?

Rachel J 12 Jun 2009, 23:16

Melyssa. Yes I've done that a few times. At least you can see what theframes look like from a distance. But last time I had my check-up my optician showed me this kind of camera she has got and it takes your picture wearing the new frames you fancy. Then you can take the off and put your proper glasses back on and see yourself in the screen. The only thing is you aren't able to see what you will look like wearing them once the lenses are fitted. And that makes quite a bit of difference with my rx. And yours I imagine.

Rache J 12 Jun 2009, 23:11

And. My current pair are RE-11.75 and LE -12.50

And 12 Jun 2009, 14:17

Rachel J, what's your prescription ?

Melyssa 12 Jun 2009, 12:41

Rachel J,

Yes, that is the one problem with trying on glasses. You can't tell how good they look until you've already had your prescription lenses put in them. But I always get as close to the mirror as possible. Even better, I would have one of the saleswomen model the frame for me. In fact, that's why I bought my first pair of drop-temples, because I could see how pretty the frame looked.

Rachel J 11 Jun 2009, 22:58


I saw some really big frames yesterday in a new opticians that has opened near us. I couldn't resist going in and trying them on! But I had a terrible problem trying to see myself in them. lol

Melyssa 11 Jun 2009, 13:16


That would be fab! All I need is for the lenses to be 2.5 inches in diameter or thereabouts, and the frame should fit me better. I'd love to have 3 collections -- a drop-temple one, a top-temple one, and a mid/split-temple one. :)

Rachel 10 Jun 2009, 23:54


Glad you approve of my comments. I reckon that in another year or two, frames will have got to how you like them and you can start with a new collection. lol

Rachel 10 Jun 2009, 23:53


Yeah I think RE-15.00 and LE-16.00 would be amazing for me. But you have to decide for yourself about what you want to do. It's very personal I think.

Melyssa 10 Jun 2009, 12:51


You're absolutely right about the more bold colors now in frames. It's too bad they're too small for me, which is why I wear big, bold, and beautiful glasses from the 1980s and early 1990s, in addition to finding the occasional large pair nowadays.

Danbert 10 Jun 2009, 11:27

Thanks Rachel - it's great by the way that you enjoy having to wear glasses. BTW, why would -15D in particular be your dream Rx?

As for me, it's just the questioning that would be very difficult to handle. You see, I really cannot lie with a straight face. I really need a legit Rx so that I can honestly tell people that I need glasses. That's why I'm tossing up the contacts idea, because it's unlikely anyone will notice and could make my eyes dependent upon correction.

I should of course do an eye exam - who knows, perhaps I'm -0.5D shortsighted or something in one eye. But I really doubt it... unless I cheat. But I'm not good at that either.

Rachel 10 Jun 2009, 11:07

Danbert. I've just posted to Induced Myopia about my boyfriend. No, definitely not, I don't think you are being at all stupid. But to be honest I'm sure wearing contacts are the answer. At least with glasses, if they are too strong for you eyes to take at first, you can pull them down your nose a bit. The important thing is to wear an rx that you are comfortable with "absolutely all the time" and no giving in at any time of the day. Just think to yourself, "I wear glasses and that's it." "I don't take them off until I get into bed and go to sleep." Then as soon as you waken up, stick them back on again. Your eyes will get to really need them then, and you will want to wear them all the time. Don't be too ambitious at first, but just keep edging the rx up about every six months or so. Then your eyes will have plenty of time to adapt. It's not at all stupid wanting to wear glasses because glasses are simply brilliant and people look really cool in them.

Danbert 10 Jun 2009, 10:56

Rachel: The first time I tried them it took me some hours to not feel dizzy and disorientated, but now I can put them on and my brain almost instantly adapts. It's just the warping on the edges which persists a little bit, but not too badly... so as you say, I could handle a higher Rx easily enough.

I have tried -5.00 contacts (which is probably -6.00 at least in glasses terms?) and it was pretty wild (blurry that is); not to mention scary because it was the first time I had put them in my eyes. Unfortunately, I could not accomodate to reading distance too well... at least not within 5 hours of having them on, and what I could focus on was too minified to be useful.

So none of this is going to have any permanent effect. As I said in the Induced Myopia thread I'm not going to do anything until I'm sure it's what I want to do. What I do know is that I just love glasses alot.

I could try again with contacts of a lower prescription (maybe -2.5 or -3) and try wearing them constantly for 3-6 months. Perhaps then I'll be able to get a reasonable legit Rx.

BTW I don't want to wear contacts; they're just a means to an end (glasses).

Tell me if I've gone bonkers, please, before I actually do anything :D

Rachel 10 Jun 2009, 10:34

RL. To be honest, I don't think you can really complain if you have reached -15.00. It would be my dream rx. I think you are so lucky. I'm hoping to reach RE-15.00 and LE-16.00 before my eyes start to settle down. Wish me luck. lol.

Rachel 10 Jun 2009, 10:31

Danbert. That's great you like wearing glasses for fun. I suppose though with only -2.50 the minus effects aren't going to be all that great when you are wearing them. If you wore them fulltime it would soon seem perfectly normal to you I reckon. Have you ever considered wearing a higher rx? it would probably be worth it in the long run. It would give you that really sharp crisp vision I so much love.

RL 10 Jun 2009, 08:02

Rachel, As to whether I would want to be more myopic, I don't know. But since I can't really do anything about it, I've decided to simply take things for what they are. Having lots of different glasses to wear (costs about the same as having a bunch of shoes) for different occasions is fun. Anyway, I just accept strong glasses as part of me and have decided to enjoy being who I am.

Danbert 10 Jun 2009, 07:53

Apologies for the double posting.

I meant to say that the parallels "jump out at me," not out of me :)

Danbert 10 Jun 2009, 07:41


I'm into photography somewhat and the parallels jump out of me.

Regarding "feeling tall", the wide angle lens in a camera system is similar in effect to minus lenses on glasses. When I look towards the ground through my camera with this type of lens, I feel very stretched and tall. Furthermore, the sides of the image are very slightly warped (alot of engineering goes into minimising this effect), just as they are with strong minus lenses.

I have a pair of -2.5D glasses ordered online which I wear "for fun" and experimentation when no one else is around. I feel "taller" (though I'm happy with my height already, except for the fact that I'm not short enough to be really good at limbo anymore) and the sides are a little warped but this effect slowly disappears as I get used to them.

RL 10 Jun 2009, 07:10

Rachel, My Rx seems to be doing quite well at growing stronger with no help from me. My first glasses were at age 12, around -1.5D I think. By 21 I was at -10 or -11. I wore contacts for nearly 20 years then stopped. By then I was around -13.5, and now I'm at -15. So the progression continues. Luckily everything else is healthy; no retinal problems etc. We'll see where it ends up.

Rachel 09 Jun 2009, 23:13

RL. Yeah that's like I said. It's as if stronger glasses push the ground away from you kind of. That's what make me feel taller. It's kind of weird at first but really really interesting. I think it must be part of the minification effect minus lenses have on your vision don't you. Like making things small to make them sharp and clear. I think at 44 you should be able to increase your rx quite a bit more yet with a bit of luck don't you?

Rachel 09 Jun 2009, 23:09

Melyssa. I agree Mel there are some really brilliant designs now in plastic. Like ones that are really noticeable. I know a girl who wears black an yellow ones with really wide sides like that fill her face. Even though her lenses aren't all that thick they make her look as if she realy realy needs glasses, which I think is so cool. Like evn if you had just started with glasses and you chose some of these frames that make a statement, everyone would immediately notice you've got some. Like " wow, did you know, Rachel has started wearing glasses now." Its' great.

ehpc 09 Jun 2009, 19:32

Rachel - your 10.54 post - PERFECT :) Pete

Melyssa 09 Jun 2009, 14:02


You're better off with plastic frames. I went with the metal ones when they were practically all that existed in the mid-1970s, but I was glad to get back to wearing plastic frames again when they returned to prominence. And my prescription was maybe half of what it is now.

RL 09 Jun 2009, 11:48

Rachel, About feeling taller...the weird effect is if I take them off I feel much shorter. Of course if I take them off, I can't see a thing. Everything is blurry past about 6.5cm. Needless to say; I don't go without glasses. 44.

Rachel 09 Jun 2009, 10:58

RL. That sounds so brilliant. Do you actually feel taller in them, like the pavement seems further away or anything? I love that experience when i get stronger lenses. Do you mind saying how old you are? I've started having eyetest every six months now and I think its worth it to keep fully corrected or slghtly over-corrected as the case may be. My dad seems quite happy to foot the bill, so I might as well take full advantage of it.

Rachel 09 Jun 2009, 10:54

Pete. I probably will now my lenses are so thick. My latest pair are slightly bigger and really make a statement on my face. Like, "Hey there, I need strong glasses." And when I walk down the shopping street, I can't resist looking at my reflection in the shop windows, thinking whose that girl in thick glasses.

RL 09 Jun 2009, 09:25

Rachel, I've had the new glasses for a day now, and I completely love them and especially the way things look through them. I had probably been undercorrected for a year or so; it's great to have everything be so nice and sharp again. I hope this lasts for a while. I'll probably go for a check-up sooner next time...waited over two years. I really like the vision with the plano fronts. Less distortion than with biconcave, but I had to go to the very high index to get away from biconcave lenses which I have in some of my older glasses.

ehpc 09 Jun 2009, 09:07

Stick with hot rectangular plastic frames with wide sides, Rachel :) Pete

Rachel 09 Jun 2009, 09:02

Galileo. Sorry, you said rimless. Yes I love them but my lenses are too thick now for me to have them which is a shame. Lucy my firend is about -5.00 though and she used to wear them adn I know she's love them in flat fronts. Give me the make if you can.

Rachel 09 Jun 2009, 08:50

Galileo. That's interesting. No one has ever told me that before. I wish I had know earlier. What sort of frames? Are they high index lenses? Or are they standard plastic?? I'd love to hear because I know other people who like the appearance of them.

Galileo 09 Jun 2009, 08:28

Rachel, there must be some cosmetic options for flat fronted lenses. I have a work colleague whose Rx is -4.25, her glasses are rimless and they have absolutely plano fronts to the lenses. She has two pairs the same, both made in Hong Kong.

Rachel 09 Jun 2009, 06:02

RL. Two years ago when my rx had reached RE-7.25 and LE-7.75 I got this desperate urge to wear glasses that had lenses with flat fronts. I'd seen the receptionist at the optician's where I go was wearing them, but I was much too shy to ask what her current rx was. I mentioned it to a few people in Lenschat and in the end I discovered that it was Emily who had a passion for them as well. She told me her lenses had started to flatten out on the fronts when her rx was approaching -9.00 and that by -10.00 they had gone totally flat. Can you imagine my desperation next time I went for my eye exam? I just knew I had to push like mad to achieve an increase of well over another 1 dioptre in each eye to stand any chance of my lenses flatten out. Luckily my in 12 months my eyes had really gone downhill and I was actually struggling to recognize people when I was out unless they were quite close, so I knew I could lie quite a bit when it came to reading the letters. In the end I achieved an increase of -1.25 on both eyes giving me RE -8.50 and LE -9.00 and when I collected my new glasses I was really thrilled with theri appearance. Both lenses were almost flat. It was my dream come true.

Rachel 08 Jun 2009, 22:03

RL. They sound totally amazing. I bet you felt great when you first put them on and walked out of the opticians wearing them. I bet you felt like saying to people in the street, "Hey I've just got new glasses and look how much stronger they are!" What did the girl in the opticians say when she first put you them on? I bet she was stunned by the high minus effect and the way your eyes adapted to them immediately. Did she tell you they may get a lttle bit of getting used to, like she did me last time I had an increase. I love it when she says that. Anyway congratualations on the new rx. I think its brilliant. Personally I'm not quite there yet but still trying. lol

RL 08 Jun 2009, 14:53

Hey Rachel, I collected my new glasses today. You would approve. They are full field (not myodiscs) show plenty of power rings, and huge cut-in. My face appears to be under four inches wide through the lenses. They are the really high index plastic, so they're not all that thick; just 8mm at the outer edges. Not bad for -12, -15. The fronts are completely flat and the lenses are coated to minimize reflections. My eyes are more visible than with uncoated lenses, but they look really tiny. Best of all, things are really, really sharp and bright.

Rachel 08 Jun 2009, 10:51

And. Probably RE -9.00 and LE -7.25 I would guess. Her glasses must be quite thick and her right lens will most likely be totally flat on the front surface, which I love. Her left lens will be pretty flat on the front as well I should think. How old is she by the way? From what you say her rx should keep increasing for a while which may please you by the sounds of it. lol.

And 08 Jun 2009, 09:04

My gf also says she has better vision with contacts rather than glasses and I think her specs prescription will be up to date, I think they were new last year. If her contacts are -7.50 & -5.95 how much higher is her glasses rx.

Rachel 08 Jun 2009, 04:44

wondering.. You've got a high minus rx like me but I've never actually tried contacts. I'm now RE -11.75 and LE -12.50 which is quite a bit higher than you. All I know is the higher minus lenses get the more curvy the insides of the lenses get and this kind of distorts your peripheral vision until you really get used to it. Even then sometimes it can be quite difficult if you don't really turn your head when you look sideways. I've actually got some glasses with high-index lenses and some with standard CR39 lenses, both with same rx now in case of emergencies. The glasses with standard lenses are pretty bad for curviness. When I first walked out of the opticians wearing them, the doorway looked all was really weird. When you say it looks clearer if you look though the bottom of you lenses, I think that means you need strong glasses again. Thats what I do when I'm needing another increase to read signs and things at a distance. Although I don't wear contacts, I know that glasses need to be stronger because they are are further away from your eyes. And the higher you rx gets the more difference between glasses and contacts you need. Like if you need -12.50 for glasses, you'll probably need something like -10.50 for contacts. -2.00 less. A girl I know also told me that she can actually see a lot better with her contacts than with her glasses, but her glasses are slightly out of date and not really strong enough for her anymore. I think next time she has her check-up she'll get new glasses for emergencies and she may decide to wear them more. I hope this helps.

Aubrac 01 Jun 2009, 07:23

Sussex Vision

Interesting web site with every sort of lens and test equipment you could think of - and a lot you've probably never seen before.

They have secondhand items and at the moment have a set of about 300 trial lenses in a beautiful inlaid wooden case - new cost over £1,000 and asking for offers.

Their website is

Phil 28 May 2009, 10:23

I got it from Sussex Vision in the UK. It's very good quality. Spheres (+ and -) from 0.12 to 20.00. Cylinder (+ and -) from 0.25 to 6.00. Some prisms and odds and ends (occluding lenses etc). About 225 lenses all told. They come in a smart large briefcase.

Mark 28 May 2009, 10:01


Where did you get them, how big is the set and how much did it cost, i have considered it in the past, but never gotten around to it.

Phil 28 May 2009, 08:40

I have just acquired a trial lense set and a trial frame. What fun I've been having!

What has, however, struck me is how difficult it is to get exactly the right degree of correction.

At my level of myopia (around -3.50 to 4.00) the 0.12 lense makes no difference at all either way. And it is hard to judge the effect of the 0.25 lense.

My current (optician's) rx is -3.75 sphere in one eye and -3.50 with -O.50 cylinder in the other. But the best corrected vision with my "kit" seems to be at about -3.50. I have tried making that up with -2.00 of sphere and -1.50 of cylinder which seems to give me the clearest vision of all.

I find the prism lenses interesting: they seem to have no effect at all. And of course dropping in the add for close correction is such a treat!

Every OO should have a set!

wondering 21 May 2009, 10:39

I have worn contacts and glasses for a pretty long time and have a prescription in the -8's with astigmatism too for both eyes. I've been wearing my glasses more in the past year since my eyes seemed to be becoming less tolerant to contacts. So I ordered some prescription sunglasses from my regular eye place and picked them up the other day. Because of pricing, I didn't pay for the hi index lenses and went for the regular plastic instead. Since the frames are pretty large I was more than a little worried about how thick they would come out but the guy who helped me told me that they would do the lenses very dark and in the same color as the frame and set them in the frame so as to make them less noticeable. I have to say they did a really good job. The lenses are about the thickest I think I have ever had but you really can't tell unless you inspect them closely.

However I have another problem with them. I dont see as well with them. When I picked them up from the store I was wearing contacts and he even made me take them out to try on the glasses to be sure they were ok. They are very quality conscious there; in front of you at this place they even put them in the little machine that measures the lenses to make sure they are the right numbers, and he concured that they were. However, he didnt do an actual exam on how I saw out of them or anything, and with a quick look around they seemed fine to me. Since I was in a mall and had more shopping to do, I took them off and put my contacts back in.

I've worn them a few times now. When I initially wore them, walking made me a bit dizzy, I guessed because of the big curve of the lens(much more than my very thin (and much smaller framed) regular glasses. I noticed immediately that everything to my sides amd out of the lower part of the lenses looked very "curved." I am used to that now even when switching from my clear glasses to these. What does bother me is that I have noticed when I am driving especially, I find myself tilting my head back to look out of the bottom (stronger?) part of the lens, and if they slide down my nose even a bit things are blurry. This never happens with my normal glasses. Should sunglasses be made in a stonger prescription than clear glasses? Or does the material of the lens make a difference to the prescription?

DWV 13 May 2009, 15:53

Try asking to have the lenses made as thick as possible. Hopefully the lab rat will enjoy doing something different and apply all their skills to produce the thickest, rather than the thinnest, lenses possible.

Asking for "as flat as possible" as well may help, since plano lens blanks are presumably made to be used for higher power lenses.

Cactus Jack 11 May 2009, 16:47


Changing the base curve is a possibility but it can cause some edge distortion.

You could easily add up to 10 diopters base out in each eye if you wanted to and it will add about 1 mm per prism diopter edge thickness to the outer edge. The inner edge will be thinner, but not by as much.

The PD in your glasses will need to be reduced by either you or the lens maker (but not both) by about 0.25 mm per diopter for the total number of diopters in both eyes.

Wearing prism will cause your eyes to converge by about 0.5 angular degrees per diopter as if you were reading. It will not be particularly noticeable to others until you get over about 10 in each eye.


newby 11 May 2009, 12:41

OK, thanks for the suggestions, I was only thinking about a thickness at the edge of say 5mm, can this be achieved with different base curve options on the lens blank? I was wondering about adding some base out prism to my prescription, would that help much, how much could I tolerate without being uncomfortable? I'd really like to use my existing frames which are for sort of medium sized lens.



Cactus Jack 11 May 2009, 09:55


There are two possibilities for thicker edges in your current Rx. One is to get frames with larger lenses. Edge thickness is a function of lens size. The other is to ask for the lenses to be made using a thicker blank such as safety glasses.

Larger frame sized are coming back into fashion. Thin lenses using hi index are in fashion today so most lens makers will try to make the lenses as thin as possible. You might try Optical4less special makings, I have seen some pictures of very thick low Rx glasses they made.

Other, more involved possibilities are GOC and wearing significant over correction. The latter could increase your myopia.


newby 11 May 2009, 09:02

Can anyone help? I was wondering if there is any way I can get my lenses made up to look a bit thicker at the edges. I only have a weak presciption (L -3+1x80, R -3+1x135) so they always come out quite thin looking. I have a semi rimless frame and I would like to have them look a lot thicker which would look good with polished edges. Is there anything I can ask for when I get them made? Is it possible to do this, I already ask for standard CR39 lens?



Lisa 20 Apr 2009, 08:36

Lots of bluriness!

And 17 Apr 2009, 16:03

Lisa, perhaps we're on the wrong thread now but what do you see without correction ?

Lisa 17 Apr 2009, 15:27

It's hard to say. I think even at -6 it would be hard with having to get a few inches close to see anything clearly but at least i wouldn't walk into people!

And 17 Apr 2009, 13:55


At what point would you have tried ? Did your script get stronger quickly or over many years ?

Lisa 17 Apr 2009, 12:35

I can't even begin to imagine shopping without glasses with my rx of -19d! Except with a guide dog, lol!!

Clare 16 Apr 2009, 10:51

And - well I'm full of nonsense aren't I because though I say I could easily do a Sainsbury's shop bare-eyed, I rarely do. In fact I can't remember the last time I tried. I generally put my contacts in when I'm going out as it's so easy to. No need to do otherwise.

My only problem is I have occasional problems with a thing called a pinguecula (sp) which is a piece of skin on the eye. It can cause be sore and a few months ago the optician forbade me to wear contacts for a week. Of course I sort of complied, but only indoors! That's the only thing that might make me venture out to test how I perform without contacts. I'll let you know if it happens!

ehpc 15 Apr 2009, 15:32

You don't check the prices? Aaaaargh ! Clearly you are not Scottish :)

And 15 Apr 2009, 15:11


When was your last challenge ie the last time you were without lenses when perhaps life would have been easier with them ?

Clare 15 Apr 2009, 11:21

Aubrac - you made me laugh! Actually I know my local Sainsbury's inside out so it's not that much of a challenge - I don't need to read the signs on the aisles and I don't often check the prices!

Aubrac 15 Apr 2009, 09:09

Clare - it really is a very individual thing, the ability to go without glasses. I'm amazed at your confidence in doing a Sainsbury shop with uncorrected -2.75/-3.00, I struggle doing it wearing lenses!!

On the Going without Glasses thread there is the story about a -4.00 German girl who slipped and lost her glasses and tried to crawl home on her hands and knees!

It does remind me of when I was doing some office interviews in London and the lady I was talking to peered and squinted at me from behind her desk. She took me on a tour of the office and various people acknowledged her but she took no notice. Whe we got back to her desk, she held up a paper and put on a pair of at least -6.00 glasses to read it, then immediately took them off again, how she managed to get home I can't imagine!

Clare 14 Apr 2009, 14:08

Guest - -2.75 is quite blurry but its possible to get about without them. I have -2.75 & -3 and though I don't often go out without my contacts, I would if I needed to if I didn't need to drive and if it didn't need very good vision. I could easily shop in Sainsbury's because I know where everything is but I wouldn't want to try and find a friend in a large/dark/busy place!

gwgs 13 Apr 2009, 00:23

Another nonsensical post from "kate" - clear off and leave us to discuss sensible points of 0-0 matters instead of spamming these pages.

It would be utterly ridiculous to get -7's in myodiscs, quite aside from the fact I don't think you could get them made!

Guest 13 Apr 2009, 00:20

Like Lenses

Did your friend seem to mind needing her glasses all the time now? What frames, did they look good?

And how is your new prescription? No issue for you as I remember you already wore full time.

Kate 12 Apr 2009, 00:10

I have a script of -7. My lenses are thick and heavy, so i have been advised to get myodiscs for my new glasses. I'm collecting the myodisc glasses in a few days. It will be good to wear lighter glasses but i have some concerns about their appearance and acuity. But there again my eyesight is bad now so i guess i have to get used to the idea! The alternative is hi index but i find problems with the vision with these so i've been prescribed unblended myodiscs now.

Like Lenses 10 Mar 2009, 22:13

Over the weekend, went on a date to a concert with a female friend that I see on occasion.

She was a part time glasses wearer, but showed up wearing a new pair that looked somewhat stronger. On the way to the concert she said that she had just gotten the new glasses and now needed to wear them full time. She said her Rx is now - 2.75, and her vision without correction is very blurred.

At the concert we were seated about the center of the seating area,and with my glasses that I wear full time, everyone on stage was a bit blurred.

I knew that I need stronger glasses, but have been lazy about making an appointment.

When I mentioned that I couldn't see the stage very well, she offered to let me try her new glasses. Everything through them was quite clear, so we shared them the whole performance.

I had an exam today and my new glasses are now Rt. -2.50 -75 cyl. @177 Lt. -2.50 -.75 cyl @ 180. Previous Rx was Rt. -1.50 -1.50 cyl. @176 Lt. -1.50 -1.50 cyl. @ 176.

My nearsightedness has increased, but astigmatism has decreased.

I always like the super sharp vision with new glasses. I CAN JUST ABOUT COUNT NAILS IN MY NEIGHBORS SIDING!

mysuperduty 23 Feb 2009, 14:13

HI. My son (18) has a very high rx - 22 and -23.50. I couldn't find a search, but I need help finding a place that will put thin lenses in my son's frame that look thinner than lenscrafters did. I usually like to have thicker glasses myself, but this is directed more for my son. I want to get him the thinnest lenses possible without going to a myodisc. I know Optical 4 less has good prices. That is some of a concern. I think the way to go is the 1.74 lens? Help me out here guys. THX! my direct email is

Phil 23 Feb 2009, 10:49

Louise, it seems to me that, if you don't have any issues with being a gwg, and you find that your eyes object to taking your glasses off, you'll soon end up a full-time wearer! Good luck!

Louise 23 Feb 2009, 09:47

Thanks Aubrac!

Aubrac 23 Feb 2009, 00:58


You will find it is the -0.50 of astigmatism that is causing strain. The problem with astigmatism is that nothing you can do, e.g. using eye muscles, squinting, etc, will make any difference.

Depending on also the angle of correction, letters will be confusing, an 'n' can look like an 'h'. Your right eye is probably dominant, and in trying to see clearly, is causing muscular strain that will lead to headaches.

Louise 22 Feb 2009, 07:03

Hi Phil, Aubrac, Eyespy and thanks for your responses. I’ve slipped into a routine now with my new glasses and most people have seen them and commented on them. I said about a week ago that my right eye was protesting. It has bothered me quite a lot this week so I have worn my glasses more than I originally though I would and I must say that has helped a lot, although I can’t work out why all of a sudden I am getting this when the only difference is a -.5 of astigmatism in that eye, otherwise it’s the same prescription. I even found that it happened when I’d been on the computer for a while even though I still feel I can see the screen without them. So I’m just taking it as it comes and we’ll see what happens.

Phil I don’t have any issues as such with glasses. To me they’re just something that lots of people wear nowadays but I wouldn’t be one of those people who wear them all the time just because they’re fashionable either!

Dieter 20 Feb 2009, 07:17


I had a lensectomy in my left eye 3 years ago (lens replacement) that corrected that eye so well that I can see 20/20 distance. I was encouraged by my surgeon/doctor to try functioning without aid. Due to the inflexible lens, that eye sees nothing up close. My right eye, which still needs a -3.25 script to see distance, does all the near vision. I do most activities with this unaided monovision comfortably. It surprised even me because I had done monovision for at least 5 years prior to that using contacts but of only about a -1.50 difference.

Two things worked in my favor, though. (1) The corrected left eye is my dominant eye (i.e. it was the eye that had always been corrected for distance with contacts). (2) I’m obviously predisposed to being a good candidate for monovision. Not everyone is.

Aubrac 20 Feb 2009, 06:21


I don't really find any problem or distortion wearing only one lens. I have often driven wearing one lens but you have to be careful, as depth perception is reduced and judging the exact position of the car in front is difficult.

Using one lens for me is a rareity and using two is definitely more comfortable.

Phil 20 Feb 2009, 03:36

Louise, you've gone quiet! How is the glasses-wearing going?

eyespy 17 Feb 2009, 16:36


Interested in your experience here, do you not experience any distortion with the equivalent of a -3 difference without contacts? I wear -3 myself and have found it odd to have only one eye corrected, definately couldn't do it for long!

guest 17 Feb 2009, 15:48

Personal preferences notwithstanding, I understand that anything beyond -2.50 is a definate full time wear. I've heard that -2 is often the trigger so would expect that Louise would find it best to wear full/most time.

Aubrac 17 Feb 2009, 05:55


Eye care professionals do say that the brain receives images from the aprropriate eye and this quite true but only when there is a significant difference between the two.

I wear -5.00 add +2.00 contacts and with only one lens I will see distance perfectly with one eye, but if I try reading my brain switches to the other eye.

With a smaller difference such as yours, I don't think the brain will automatically accept one image in preference to the other. However in trying to achieve best binocular vision there could well be some pull resulting in muscular discomfort and strain.

Fulltime wear will be the most comfortable course but if you try extended periods of not wearing when you do not need to focus, e.g. outside when focussing on infinity by looking at the sky, you may find a halfway course that suits you. It is after all entirely up to you.

eyespy 16 Feb 2009, 15:24


It's not surprising that your right eye protests as there's a clear 1D between it and the better eye. My wife has the same. It bothers her because she gets distortion in the worse eye which distorts her binocular vision. Overall that results in alot of discomfort so she sensibly chooses to wear her glasses fulltime. I guess that's what you're experiencing now you have your new Rx.

I've heard that eye care professionals say that the better eye ignores the worse but my wife would dispute that. If you're experiencing discomfort then there's no harm in wearing the glasses to relieve it and you'll be improving your binocular vision at the same time.

Phil 16 Feb 2009, 03:42

That's what they mean by saying that. You don't recognise a cmpliment when you see one!! I think that your right eye is at about the point where fulltime wear is what's needed. Mind you, I'm a fine one to say that. Here I am squinting at the screen as I type, with a rx a full -1 above yours! Maybe you'll eventually just slip into being a fulltime gwg without realising. Do you feel comfortable wearing glasses? Or do you have some feeling of shyness or embarrassment?

Louise 16 Feb 2009, 03:37


Yes certainly more but no way near all the time. My right eye protests a bit without them. I haven't had any comments about how they suit me only that they like the style.

Phil 16 Feb 2009, 02:19

Are you finding you are wearing the new glasses rather more Louise? Have you had any compliments about how you look in them?

Louise 16 Feb 2009, 00:34

JP, Phil

Yes it could be that she's a bit fascinated by glasses. She hasn't asked to try them on yet, we'll see if she does!

JP 14 Feb 2009, 05:35

Louise - Your change in prescription would make little difference to the appearance of your lenses, even to the keenest observer.

A wider frame would make minus lenses appear thicker, although many here would compliment you if that were the case!

Most likely your friend had simply noticed that you've got new frames and has assumed that you needed stronger lenses (or, as I don't like to hear people say, that your eyes have got "weaker").

Who know.... Perhaps your friend likes glasses too!

Phil 13 Feb 2009, 01:22

I wouldn't have thought they'd look that much different Louise. If it concerns you you could always get thinner lenses. Maybe your friend has just noticed that you are wearing them more. Are you?

Louise 13 Feb 2009, 01:02

One of my friends asked me yesterday if my new glasses are stronger. It's only .25 and .50 astigmatism extra would that make them look stronger, can a .25 be noticeable? My last pair were nearly 5 years old, has the technology changed signficantly to make lenses look different?

This prescription is now -1.75 & -2.50 x -0.50. Thanks!

Dieter 27 Jan 2009, 19:40


I was just laughing at the mechanical translation that was generated. What a hoot! I totally understand what you were trying to accomplish. I would never laugh at you my friend - I have too much fun reading your stories.

specs4ever 27 Jan 2009, 16:58

Hey Dieter, all I was trying to do was create some more interest in Micha's request for a translation. Like I said, what the online translation gave wasn't really comprehendable, so I am hoping someone can make sense of this. So, thanks for helping, because the more dialogue, the better chance of a proper translation.

Dieter 27 Jan 2009, 13:18


"All your base are belong to us"

Sorry, I just had to do that. Translation can be so tricky and hilarious.

specs4ever 27 Jan 2009, 12:51

Hi Micha.

No one else seemd to be able to help you translate, so I went to an online translation. It still doesn't quite make sense, although it looks like a conversation between 2 people with similar problems

This vybrusenie slides became a 300Sk. Front to look nice, but how to change the angle it is seen to grinding, so send more photos. Again, the co mam dioptres su -26 and -28. And this, I would you like to ask whether the silicone when you have half of the year or how many you've mentioned, you have also selected intraocular lenses? I ask is because you chose me, that is, through the glasses still visible and it must have prelepene. And when you sil.olej he chose to help you? Sice do not know which use me, because now I first met with them and gave it to me there to make me threaten us retina, which I odlupila and natrhla. After a month and a half, the lower part uvolnuje me more and tomorrow I go to check hadam there will know more, so we do all descriptions, from there you had a similar case because I am desperate, because we are not, or to help when I to be lifted.

Cactus Jack 27 Jan 2009, 09:04


Prism is a little tricky. Base out prism will make the outside edge of the lens about 1 mm thicker per diopter and the inside edge thiner. Wearing Base Out prism causes your eyes to turn inward (converge) like they do when you read or look at something close. It is something that occurs naturally. Base In prism will make your eyes turn outward. That is something that does not normally happen unless there is a muscle imbalance problem and it is difficult to adapt to.

If you decide to experiment with Base Out prism you should reduce your PD by about 0.25 mm per diopter of prism so that the optical center of the lenses is pretty close to your axis of vision. The actual turn in is about 0.5 angular degrees per diopter. You have to get up to around 10 diopters Base Out in each eye before others will notice it. 10 in each eye is about like reading at 10-12 inches.

If you want to discuss this in detail, contact me at


Brooklyn Boy 27 Jan 2009, 08:35

My actual prescription is around -5 both eyes, If i order eyeglasses with prism will that make the thickness of the lenses thicker than normal? I never had a prism correction before so I don't know these things I just think that I would get a kick out of it if I show up somewhere with my eyes looking in or out...

Cactus Jack 27 Jan 2009, 08:15


Yes, it depends on the direction of the base of the prism. The direction the eye turns is the opposite of the base.

For example, Base Out is for turn in.


brooklynboy 27 Jan 2009, 07:59

I was wondering, if you eyeglasses that has prism correction when you do't need one would it make your eyes turn in or out?

Micha 23 Jan 2009, 08:07

A couple of days ago someone from Slowakia sent these photos to me and #2, #3.

Coud someone of you translate the comment into English?

> To vybrusenie sklicok stalo jedno 300sk. Spredu to vyzera pekne, ale ako

sa meni uhol je vidiet to brusenie, preto posielam viac fotiek.

Opakujem, tie dioptrie co mam su -26 a -28.

A este by som sa vas chcela opytat, ci ten silikonovy olej, ked ste mali

toho pol roka alebo kolko ste to spominali, mali ste aj vybranu

vnutroocnu sosovku? Pytam sa preto, lebo mne ju vybrali, cize cez

okuliare nevidim a stale ho musim mat prelepene. A ked vam ten sil.olej

vybrali, pomohlo vam to? Sice neviem ake pouzitie ma, pretoze teraz som

sa s nim prvykrat stretla a davali mi ho tam nato, aby mi tlacil na

sietnicu, ktora sa mi odlupila a natrhla. Po mesiaci a pol sa mi spodna

cast uvolnuje stale viac a zajtra idem na kontrolu, hadam tam budem

vediet viac, Preto vam to vsetko opisujem, ze ci ste mali podobny pripad, pretoze som zufala, kedze neviem, ci to pomoze, ked sa mi to


Cut-in UK 15 Jan 2009, 22:47

Jenny, the Henry Poole clip, from the brief view through the lenses, looked like a +0.25 or +0.5; no more. If you are -2.5, you should be able to get a bit of edge thickness with the basic CR39 plastic lenses which are the lowest refractive index of 1.49. It is also possible to order the lenses with plano (flat) fronts rather than the slight outward curve. Your other alternative is to do GOC, as I do, wearing 'plus' contact lenses and order a higher minus prescription than you need. If you use CR39 low index lenses, they can be really thick at -5.00 or so. It depends how much you want to do it, but it means full-time wear and your friends and family may notice the increase so you may have to give them an explanation that you can stick with. You may also get to like the 'look'

You may prefer to try the former (and easier)suggestion, with an internet pair at very reasonable cost. There are 'tables' that can tell you how thick your lenses will be at any Rx in any material. Ask us more if you need to. Your age and occupation may influence the choice, and our advice.

Aubrac 15 Jan 2009, 04:51


Only just noticed your post - have you got your new lenses now?

My prescription is exactly the same as yours except for the add (which I need) but didn't have made up. My lenses are about 4.5mm thick at the edges.

How are you finding your new glasses?

Jenny 15 Jan 2009, 03:32

its my question.. sorry i forgot to write my name

 15 Jan 2009, 03:30

this is clip from movie "henry poole is here "

Many people are claiming that this is just plano glasses with low index glasses.

if this is plano glasses.. i would love to know its index and make it same for me as my bf wants me to wear thick glasses.. but i have only -2.50 D..

can any 1 help ?

Andrew 23 Dec 2008, 01:06

At the risk of stating the obvious, Karly, that all depends on the frame size. My experience is about a millimetre per diopter; I tend to go for normal frames which you could put a bifocal into, rather than extra-large ones, but that all depends on your preferences.

Karly 22 Dec 2008, 22:28

Hi, I just received a new prescription:

-5.00 - 1.00 x 010

-5.00 - .75 x 175

Add +250

If I order just cr-39 plastic lenses, how thick will the edges be?

Aubrac 24 Nov 2008, 02:04

Lenses like these can be for any prescription I think.

I bought a pair which were quite old at a flea-market in Paris. They were about my prescription, -5.00, and were completely flat at the front and also very thin, thinner than a normal thin lens in my scrip.

Emily 23 Nov 2008, 19:10

Stingray -- That's what my lenses are shaped like. I'm very nearsighted (-14) but I don't have myodisks. The outer surfaces first became flat when my prescription increased from -8 to -9.

Stingray 23 Nov 2008, 18:39

Actually, I made a mistake. The inside part of the lens (closest to your eyes) is scooped out, like half of a concave lens. The front of the lens is completely flat. I looked it up on the internet and apparently the lens is called a Plano-concave lens. So what do you think? Myodisc or regular type lens?

Stingray 23 Nov 2008, 14:28

I just came across a pair of the strongest glasses I've ever seen. They have plano fronts and a concave back. I think they may be blended myodiscs. Is there any way I can tell if they are or not? What should I look for? Thanks

Mike 04 Nov 2008, 14:08

I am thinking of buying some new glasses on line. What are the best lenses, is it Zeiss or Seiko or something else? I've heard these mentioned but have never known who makes the lenses I get in my glasses from my high street optician. Thanks.

Like Lenses 27 Oct 2008, 18:57

I posted this on the Induced Myopia thread, but got no responces.

I have induced myopia that requires me to wear glasses with -1.50 with -1.50 cylinder for each eye.

I spoke with Optical 4 Less about a pair of special order glasses that would be very thick, and have flat front base curve.They said that they could make them for abou $ 200.00 U.S.

I am wondering if the quality of vision would be the same.

Does anyone have any info?

stephan 27 Oct 2008, 12:33

read this discussion about lenses... if someone wants to see what a -30.00 plano front highesIndex mineralglass pair looks like :



Galileo 27 Oct 2008, 04:47

Thanks everyone, I'm still not sure I understand any measureable benefit to bi-concave. I agree they can't really be any thinner, and I don't understand enough about the physics to get why a bi-concave should give less minification than another lens of the same prescription as suggested by RL's experience. Any real experts out there? (not suggesting you guys are not experts :))

RL 26 Oct 2008, 08:21

The most distortion-free lenses I have in my -14 prescription are 1.8 hi-index biconcave myodiscs. They have about -2 diopters on the front curve and the remainder on the back. I have noticed over the years that biconcave lenses result in a slightly less minified image than a plus base curve, and at -14 that helps. I have a pair of "normal" (non-myodisc) glasses in 1.67 plastic with nearly plano fronts and they seem to result in a slightly smaller image than the biconcave myodiscs. They also make my eyes look smaller and my head appears to be less than 3 1/2 inches wide through the lenses. They are also quite a bit thicker and heavier. Almost 10mm at the edges compared to the myodiscs being maybe 5mm at their thickest point. Those are the advantages that I find beneficial.

Specs4ever 25 Oct 2008, 22:46

But actually, "normal" lenses are not used up to -28D. I have seen very high - 1.9 index - glass lenses used up to -30D. By far the best optics are with a plano 1.9 index lens. And, with smaller eye sizes that are prevelant now, hi index plastic lenses are quite common up to -20D - and look quite good as well.

specs4ever 25 Oct 2008, 22:43

I really an't tell you what the advantages are Galileo. Back in the 80's, before high index, biconcave came into use with a prescription of around -13D. The rule of thumb was 1/3 to 2/3 rds. Supposedly, by placing some of the prescription on the front of the lens, the lens could be made thinner, however I never could see this. But by the time you got to -15, if a -15D was done in a plano front, with the larger eye sizes of the 80.s then there was a ring of no power around the area that was ground for the lens. A biconcave lens could avoid this. By -15D the choice was biconcave or myodisc. Now this has gone up to -20D in a higher index. Personally I always found biconcave lenses to be hard to wear, because of the distortion.

Galileo 25 Oct 2008, 21:38

The posts about Lenticulars made me think - can anyone tell me what are the advantages of bi-concave lenses for myopia? Why use a bi-concave as opposed to a myodisc or a "normal" high index lens? I've seen "normal" lenses in small frames used up to -28. I'd like to understand why an optician would recommend one of these options over another??

gwgspotter 22 Oct 2008, 09:20

it was just that you say that your husband seems to be on the verges of presbyopia and i wondered if you were too.

Sharon 22 Oct 2008, 08:10

yes I'm new here. i don't wear bifocals, just myopia & astigmatism as indicated in the rx i posted below. why do you ask if i wear bifocals?

gwgspotter 22 Oct 2008, 04:47

are you new here Sharon? do you wear bifocals?

Sharon 22 Oct 2008, 02:53

My prescription is -2.25D in both eyes with -0.5D and -0.75D astigmatism.

Without glasses, i think i can only read the top line of the eyechart, ie., the 20/200 line.

So I'm 20/200 when uncorrected.

Charles 21 Oct 2008, 12:06

Patrick B,

You may well be right that, corrected, I am the equivalent of -4.00. I was told some time ago that my distance vision equated to about -3.00 but that, in certain other respects, my acuity was worse than that.

Yes, even at 42, I am still getting increases on a regular basis. However, to be a little pedantic, I am not 'enjoying' them at all.

Pete 17 Oct 2008, 18:51

Is there anyone here that knows how to program and set up a lens generator?

And also maybe knows some of the design


Patrick B 16 Oct 2008, 14:12

Charles: My prescription is now -26.50 and -27.50 with only a bit of astigmatism. I think you said you had finally cracked -30 and had quite a bit of astigmatism. Funny, one would think that at 50+ I wouldn't be having any additional increases, but they do keep popping up in small increments. With glasses I consider myself to be at the level of someone who is an uncorrected -2, although the quality of my corrected -2 isn't all that great what with the minification and distortion issues. 6/60 is the American equivalent of 20/200, so I wouuld venture to guess that your visual acuity is roughly an uncorrected -4. I realize that all of this is an "educated guesstimate," but I suspect that I will reach -30 at some future point and will continue to experience a visual decline. Has your sight stabilized or are you still "enjoying" increases?

Charles 14 Oct 2008, 09:20


Like Patrick, I can see virtually nothing without my glasses except colours and vague shapes. With glasses, I can just see 6/60 (top line on a standard eye chart). Again, like Patrick I'm much worse at night.

Patrick B 13 Oct 2008, 11:45

anonymous poster -- I can't see a whole lot without correction. No, I'm not blind, but I wouldn't want to go through life without glasses/contacts. Even with glasses, I only see about 20/60. At night it's probably about 20/100 now. Luckily, I get great vision with contacts.

 09 Oct 2008, 17:11

Charles and Patrick B

What can you see without your glasses? What is it like without them?

Patrick B 09 Oct 2008, 15:41

Julian: Like Charles, I also wear lenticular lenses which I have always called myodiscs. "Lenticular" is probably a better term since it can include both plus and minus lenses where a "myodisc" only refers to a minus lens.

Lenticular lenses are an excellent choice for those with extreme myopia and, contrary to popular misconception, provide me at least with a more conventional viewing area since the distortion caused by the high prescription is minimized by the lens bowl size (in my case 20mm). My last pair of regular high-index glasses were nearly unwearable because of edge thickness, and I could only look through the dead center of the lens without having to deal with tremendous distortion. Even then, I was always aware of peripheral distortion.

Julian 08 Oct 2008, 08:15

Thanks Charles, I didn't know that. Although I've seen lenticulars, both plus and minus, often enough over the years, I've only heard the names on this forum. (Thinks: + lenticulars used to be very common before the advances in cataract surgery!)

Charles 08 Oct 2008, 00:02


The name 'myodisk' is unknown here in the UK. We, know them as 'lenticular' lenses and that is what they are called in many other parts of the English speaking world. I wear them and find them to be excellent lenses.

Julian 06 Oct 2008, 04:41

They're called lenticular, which is also a possible name for myodisks.

Puffin 06 Oct 2008, 03:18

Stan yeah sure they exist, obviously they look different from myodisk myopia glasses.

Stan 05 Oct 2008, 19:37


If I'm not mistaken, progressive lenses are the so called "no-line bifocals", so you couldn't have a progressive lens for just a -2.50 sphere. Only if your Rx haa an Add could you get a progressive lens.

If you look through a progressive lens, especially from the back, you will see the effect as the Add increases toward the bottom. For lack of a better word, to me it kind of looks wavy.

Stan 05 Oct 2008, 19:29


Does a myodisc equivalent even exist for plus lenses?

Puffin 05 Oct 2008, 17:59

Here is a question, if anyone knows the answer. We all know that for myopic glasses, myodisks are recommended beyond about -15 and essential beyond -20 unless extremely thick lenses are okay, does the same rough guidelines apply for hyperopia?

Or is it just a matter of taste?

DWV 15 Sep 2008, 15:40

And, flat-fronted lenses reflect light very obviously if they're at the right angle. You'll see that sometimes with prop glasses on TV or movies, or antique sunglasses with literally plano lenses.

DWV 15 Sep 2008, 15:37

Progressive lenses don't look much different with a -2.50 prescription. Cut-in and power rings will be about the same. You can still recognize a progressive lens, though, by how things look through the lens if the wearer turns their head.

Flat-fronted (zero base curve) lenses are normally only used for strong myopic prescriptions. Segmented multifocals (bifocals or trifocals) may be more obvious against a flat lens than on a curved lens.

 15 Sep 2008, 00:16

1 more thing .. what does it mean " flat fronted glasses " ..and how do they look ?

Nick 14 Sep 2008, 23:45

hi friends

i m having very nominal prescription of -2.50 No.s with astigmatism..

i just wanted to know if i make progressive glasses.. then how it would look ?

means in minus lenses we can see power rings... so how progressive lenses look like ? does it magnify the eye like plus lenses ?

want to know.. pls do reply

Highmyope 04 Sep 2008, 20:17

Lenti, much to my irritation, no! I can't believe I didn't bookmark it. The one "consolation" is that it wasn't an online seller, e.g., Globallens, but rather a reference for practitioners or labs.

lentifan 04 Sep 2008, 16:16

Amazing, Highmyope!

You can't remember the address, can you?

‰š 04 Sep 2008, 09:23

Making of the -48D glasses.

Highmyope 03 Sep 2008, 11:03

Lenti--I've seen a contact-lens catalog online with a line of lens that came in powers from -75.00 to +50.00!

 01 Sep 2008, 20:41


Do you have pics and an english translation for your listing?

lentifan 01 Sep 2008, 15:56

Just out of iterest, does anyone know what is the highest minus power of contact lens available?

ms 16 Aug 2008, 01:04

I offer some prism glasses on

 16 Aug 2008, 00:08



If you are interested in discussing prism's and crossed eyes

go the this URL and post a message.

Likes Prism Lenses 31 Jul 2008, 06:48

Cactus Jack,

Once again, thanks very much for your prompt and excellent reply to my last questions. Yes, I will do as you and eros have both suggested and ask Holli out, and I think (hope) that she will accept my proposal.

I have always thought that Holli is much more than just wonderful because I have always considered her to be a girl who is not only amazingly beautiful but is also amazingly talented as well (she works as a physical therapist).

It is disturbing that (too) many men (and other women) obviously only see that Holli has significantly inwardly crossed eyes and are even more obviously blind to the facts that her amazing eyes and how she has learned to function so amazingly well with them are what make her so amazingly beautiful.

I am confident that Holli will (eventually) let me see her wearing her glasses and will also tell me much more about her eyes and her vision.

Perhaps I will (eventually) let Holli read these posts.

I very much appreciate how helpful you have been to me, and I appreciate even more how understanding and how supportive you have been of both Holli and me

Likes Prism Lenses 31 Jul 2008, 06:27


Thanks very much for your advice and your well wishes. I have been planning for some time to ask Holli out on a date, and I think (hope) she will accept my request because she seems to like me as much as I like her. I want her to know that I find everything about her to be attractive, but I also want her to know that I consider her to be even more attractive (and most assuredly not any less attractive) because of her significantly inwardly crossed eyes.

I do not want Holli to ever be in any situation that may possibly cause her any embarrassment or any anguish because of her eyes or her vision, so I will let her decide when she wants to wear her glasses in my presence.

Cactus Jack 30 Jul 2008, 18:05

Likes Prism Lenses,

She seems like a very nice young woman. It is amazing what a human being can learn to do to overcome and compensate for vision problems. She has likely learned to accurately estimate where the ball is and where the bat needs to be to connect with less than ideal input. She is a survivor and a natural problem solver.

One of our members is very far sighted because of a congenital condition with about 110 total diopters of convergence. He wears about 84 BO of prism, but that does not suffice to allow fusion. He sees things to his right with his left eye and things to his left with his right eye. He has learned to do this quite well and he plays goalie (very well I might say) on an amateur soccer team.

My suggestion is to stop worrying about how she does it and do as Eros suggests, as her out. You may find that she is a wonderful companion and if you are patient you may learn something about vision, optics, and compensation. Hopefully, she will be very appreciative of your interest and admiration.


Cactus Jack 30 Jul 2008, 17:48


11 BO in each eye causes approximately the same amount of convergence as reading at a distance of 28 cm or about 11 inches. It is doubtful that there would be much permanent effect unless there is an over convergence tendency anyway. If you read with 11 BO prism at a distance of 28 cm it would be like wearing approximately 22 BO in each eye for distance. BTW to focus comfortably at 11 inches would require an add of +3.50 however, if you wanted to read extensively with 11 BO, I would suggest getting single vision readers for that purpose with with the sphere about +1.50, cylinder and axis you now wear, and the PD reduced by about 11 mm. so the optical centers will be very near the line of vision. Higher prism situation are much like GOC and should be approached cautiously without too high expectations of good results.


eros 30 Jul 2008, 13:53

just ask her out, for christ's sake! good luck and go for it!

Likes Prism Lenses 30 Jul 2008, 04:24

Cactus Jack,

Again, thanks very much for your prompt and excellent answer to my last question. Holli, the female acquaintance to whom I am referring, just turned 24 earlier this month.

Judging by how well Holli plays softball, her depth perception must be excellent because her hitting is superb, her fielding skills are above average, and her throwing accuracy is simply amazing.

I would very much like to see Holli wearing her glasses, but, personally, I always look forward to making eye contact with her bare eyes, especially if she is talking just with me. Whenever I have been fortunate enough to converse with her, I have always found that her eyes are very expressive and literally twinkle as they almost constantly move. Her continual eye movements have never made me feel the least bit uncomfortable, nor have they ever led me to think that she was being untruthful with me. However, I do find myself being mesmerized every time I see her unusually attractive eyes (not to mention her alluring smile). Invariably (and purposely, perhaps) she almost always deliberately looks directly at me at least once for a few brief moments whenever she is talking with me, so she must be aware that that I know just how inwardly crossed her eyes are.

Can Holli’s depth perception possibly be as good as it appears to be when she is playing softball, or has she simply learned how to compensate amazingly well for the lack of the depth perception that she may very well have (and perhaps may have always had her entire life)?

Knowing that she does wear her glasses if she has to drive her car long distances, is it possible that she might also wear her glasses if she had to engage in another similar activity, such as watching a movie in a large indoor theater or watching a sporting event in a large outdoor stadium?

Once again, I thank you (and anyone else) in advance for your help in answering my newest questions.

eyespy 29 Jul 2008, 14:20

Fascinated by why anyone would want to be cross-eyed but your choice. Why exactly?

someonewhowantstobecrosseyed 29 Jul 2008, 11:40

I've been reading the posts about prisms and had a question. I have a pair of -2.00 with 11 BO prisms that I received from optical4less. Here is my question I can wear these for extended periods and when I take them off I see double for awhile, 1. If I wore them all the time would my eyes adjust to them so I would be this way all the time, I mean when taking them off my eyes would remain crossed 2. I can't tell from looking in the mirror when wearing them, at this prescription would my eyes appear very crossed? I'm 50 years old is it to late to get my eyes to stay permanently crossed

I see extremely well with them, but i need to get another pair with bifocals

I would appreciate any help...thanks

Cactus Jack 29 Jul 2008, 07:05

Likes Prism Lenses,

It would be nice to know her age. I suspect that vanity is playing a significant role and that she has become very skilled at seeing with only one eye at a time which only provides 2-D vision (no true depth perception). It is interesting that with her glasses, she has some depth perception, many people with her condition do not develop that ability.

It is unfortunate that she will not wear her glasses more. Constantly shifting eyes make other people extremely uncomfortable, because it is a clue that the person may be being untruthful. (Skilled and successful lawyers and politicians develop the ability to lie while looking you straight in the eye.) High prism glasses can cause some slight initial discomfort for others because, in some instances, they can't tell exactly where you are looking, but they quickly learn to deal with that and look beyond the glasses to see the real person behind the lenses.


Likes Prism Lenses 29 Jul 2008, 05:06

Cactus Jack,

Thanks very much for your prompt and excellent answer to my questions. Your reputation as one of ES’s resident experts is well earned and well deserved.

A female acquaintance of mine has beautiful blue eyes that are significantly “crossed” inwards (she says she has congenital bilateral esotropia), but I have never seen her wear glasses in the more than two years I have known her. She has told me she has glasses, but she adamantly insists that she has almost perfect vision without them. She claims she only wears her glasses when driving long distances because they give her slightly better depth perception and slightly more peripheral vision. I suspect she does not like to wear her glasses because their lenses must have significant outer edge thickness and must produce a significant amount of cut-in around the edges of her face.

She is an expert at hiding the fact that her eyes are significantly crossed inwards. Whenever she makes eye contact with anyone, she almost always turns her head slightly sideways, and she constantly moves her eyes by making a variety of expressions with them.

Can her uncorrected vision possibly be as good as she always insists that it is, or is she just sacrificing her vision for her vanity?

Again, I thank you (and anyone else) in advance for your help in answering my new question.

Cactus Jack 28 Jul 2008, 04:56

Likes Prism Lenses,

It is difficult to quantify, but BO prism does produce significant cut in on the outside edges of the lens.


Likes Prism Lenses 28 Jul 2008, 03:01

Do low minus Rx lenses with strong BO prisms produce "cut-in" equal to the "cut-in" produced by strong minus lenses without prisms? For example, would -1.00 Rx lenses with 15PD BO prisms produce "cut-in" equal to the "cut-in" produced by -16.00 Rx lenses without prisms?

Thanks in advance for your help in answering my questions.

Emily 20 Jul 2008, 13:11

Hi Andrew -- I'm not a total expert, though I was the stock clerk in an optical shop for 2 years while in college. In the case of 2 different standard base curves, they make both lenses on the flatter of the two curves (I used to have to special order them). I don't think the cylinder comes into play, although I can't swear to that. Sorry -- I don't want to guess.

Andrew 20 Jul 2008, 12:07

What do you do with prescriptions of -8.00 and -9.50 for one person, and does (minus) cylinder count towards these totals or not?

Emily 20 Jul 2008, 11:42

Bryan -- Having worked as the stick clerk in an optical shop for 2 summers while in college, I became familiar with the standard base curves:

-0.25 to -2.00: +6

-2.25 to -4.00: +4

-4.25 to -6.00: +2

-6.25 to -8.00: +1

-8.25 to -9.00: +0.50

over -9.25: flat

Hope that helps!

Bryan 20 Jul 2008, 09:13

Is there a look-up chart which pairs sphere strength of a lens with its default base curve when an optician makes glasses?


DWV 09 Jul 2008, 14:18

It's worth asking for a quote from local opticians... prices vary widely. Walmart Optical, for example, does basic single vision or FT28 bifocals for $60 (Canadian). It's hard to beat that online once you've paid for shipping both ways.

DWV 09 Jul 2008, 14:10


I've had one pair done there, and the workmanship was good. They've got a very good selection of lenses.

Julian 08 Jul 2008, 12:05

Just tried again and it still hasn't worked. Sam, if it's a UK supplier you want I've found five. email me if you want the addresses: julianmungo(at)yahoo(dot)co(dot)uk.

Julian 08 Jul 2008, 11:53

I've had several attempts to post a reply to sam12744, but it won't post for some reason. It's only on this thread I've had the problem (and I've rebooted) as I've just posted to Julian's jottings. Any way of accounting for this?

guest 07 Jul 2008, 07:18

Leon will do 1.5 lenses to + or - 10. I don't know about just replacement lenses though.

Leon 07 Jul 2008, 03:51 does not seem to supply low index lenses (1.56 mid-index is their lowest index). Any other retailer?

sam12744 04 Jul 2008, 09:15

Thanks,guys.I'll have to try them,though I imagine they are both USA based,which poses a postal and Customs problem.

EyeTri 04 Jul 2008, 06:43


I have had quite a few lenses changed in my frames by and I think I will try

russell 04 Jul 2008, 04:29

Go to I have had two different pairs of narrow corridor progressives made with frames I have sent them. The price is incredible, and the quality is great. Plus service only takes two weeks or so.

sam12744 04 Jul 2008, 03:54


That is something I would like to know,too.I have yet to find an online service that will reglaze your existing frames.Those I have emailed to ask have flatly refused.They just seem to want to supply new frames,which is a nuisance,as I have some frames I really like,which suit me well and which fit(having come originally from a local optician),which I would like to be able to use for GOC.

If anyone does know of an amenable online retailer,I would be most grateful.

Leon 02 Jul 2008, 12:12

Question: I'd like to have the lenses in my rimless frames replaced. I want low index lenses (1.5) in my new Rx. Any online retailer that offers lens replacement anyone can recommend?

Tim 24 Jun 2008, 21:26

I think it has more to do with the different refractive indices of air and water, though the chlorine might have some effect.

sourgrapes 24 Jun 2008, 11:10

It also just occurred to me that I would keep on these goggles for long periods of time in order to induce the blurry vision that I would get for a while after taking them off. I assumed then and still do that this had something to do with the chlorine in the pool water, but I'm not really sure...

sourgrapes 24 Jun 2008, 10:51

I just remembered this thing I used to do with underwater goggles when I was around 11 years old. I'd fill them up with swimming pool water and put them on, and then walk around with them on to try to simulate blurry vision. I think I was trying to see what it would be like to have to wear glasses. Any thoughts on this water-induced blurriness?

Curt 05 Jun 2008, 05:28

Chuck: With readers, you move your head to look at different objects or parts of the newspaper, etc. With bifocals, you must learn to move your eyes and not your head - if you have never worn bifocals before, this can be a little tricky. When folks are fitted with bifocals for the first time by an eye doctor, that is one of the first things that they are told...move your eyes, not your head.

Chuck 04 Jun 2008, 14:27

Thanks for the site. My wife and I are new to all of this. She has worn reading glasses off and on for the past year. Is it common for her to have trouble with the bifocal but not with the pair of half eye readers? She seems to do really well with them.

Wurm 04 Jun 2008, 10:32

Here's one vendor for full frame 'sun readers':

Chuck 04 Jun 2008, 09:37

I am wondering if there is an online place that sells full frame reading glasses that are darkened to be used as sunglasses. My wife has tried the bifocal sunglasses and she has had a hard time getting used to them because she only wears half eye glasses to read when not in the sun. It seems as if the bifocal segment is set much too low the way she reads.

sam12744 04 Jun 2008, 07:17

Well ,Brent, it has been a while since I looked at their site.I'm just glad you found a source.

Brent 03 Jun 2008, 06:22

Nevermind. I found a site! has 1.50 low-index lenses.

Brent 03 Jun 2008, 05:56

Thanks Sam. I looked at their website, but I think the lowest index they have is 1.57. But, I emailed them asking if they did have 1.50 plastic.

sam12744 03 Jun 2008, 02:47


Last time I looked goggles4u did CR-39. I have a pair of bi-concave -14s from them in CR-39.

Brent 02 Jun 2008, 16:40

Does anyone know any websites that sell cr-39, 1.50 index plastic lenses?

I just bought a pair of glasses from Zenni optical, but they were 1.57 index and the edges were polished.

I'd like the regular thick plastic lenses without polishing on the edges.

Thanks so much!!

 22 May 2008, 23:25


Before you begin, wash your hands--but also make sure to dry them well, or the lens will stick to your finger.

Now, put the contact on the tip of the index finger of your dominant hand (e.g., the right hand if you're right handed) and put a drop of contact lens fluid inside the lens.

Then hold your top eyelid open with the middle finger of your non-dominant hand and the bottom eyelid open with the middle finger of your dominant hand (sort of like flipping yourself off twice).

Next, GENTLY touch the contact to your eye with the index finger. If the lens stays on your eye, continue holding your eyelids open with the middle fingers for a few seconds, to give the lens a chance to settle. Finally, let go of the lower lid, followed by the upper lid.


P.S. It is strongly advised to get an official contact lens exam to find out your eyes' base curves and the best lens size (diameter) for you (tell the dr. you want to get some of those theatrical lenses, which also require you to have a b.c. and diameter--of course, this is most easily done in the couple of months before Halloween! :)). Otherwise the whole experience may well be very painful!

 22 May 2008, 18:27

how is the thickness with -12, big round frames and 1.7 titanium lenses?

nnme 13 May 2008, 08:50

I am trialling contact lenses and am struggling getting my lenses in and out of my eyes! I think my eyes are too small and my fingers are too big.

Anyone got any tips?

Cactus Jack 11 Apr 2008, 09:08


If you are finding that the reduced vertex distance is providing better vision, you might want to consider increasing you Rx either with supplemental contact lenses or new glasses. Vertex distance changes the effective Rx by about 0.1 diopter per mm.


sam12744 11 Apr 2008, 01:23


That made me chuckle!

I can't imagine the screws would be a problem unless the lenses were made of glass.

sourgrapes 11 Apr 2008, 00:47

Oh, but, there is a small possible problem. The screws that hold the nosepads in place are scratching/drilling the inside of the lenses, because the nosepads are so close to them! I hope it won't be a problem for the lenses (they are 1.67) (?). The scratches themselves don't bother me, because it's just at the very edges and I don't use that part of the lens, anyways. :)

You know you're an OO when you stay up hours past your bedtime fudging with your glasses. :)

sourgrapes 11 Apr 2008, 00:37

Just a random comment.

I have rather long eyelashes and was having the problem of them rubbing up against my lenses. But having my (-9) lenses further away from my eyes seems to both decrease power (But I'm over-corrected, anyways), and decrease my quality of vision (less field of view, more minification). Things look so much better when the lenses are really close, so I adjusted the nose pads to minimize vertex distance and have taken to the habit of regularly trimming my eyelashes with some scissors. Now my vision seems much better and I don't have to deal with smudges.

Cactus Jack 27 Feb 2008, 12:22


The image really is bigger on the retina, which makes things initally seem bigger and closer. If she wears her glasses, the brain will usually get accustomed to the larger image and things will just look "normal" after a while. The change in size is caused by the distance between the cornea and the glasses (vertex distance). You can see the effect with any plus lens by moving it closer and farther from your eye. If you get it far enough away, the image will get confued and then it will be inverted.


CR-39 has the best optical properties of any plastic lens. It has the least spherical and chromatic abberation of any lens material until you get into optical glass. CR-39 also has a relatively low index of refraction (about 1.50) which will make the lens thicker than with high index. High index is all the rage now because it makes for thin, costly, and more profitable lenses. Edge finish will mostly affect the "power rings" of the lens. The "power rings" are really internal reflections within the lens of the edges, visible from the front. Power rings can be minimized by using a very light, 5% or 10% gray or rose tint, if they are of concern. Edge polish is considered t be a "more atractive" finish.


sourgrapes 27 Feb 2008, 11:40

Other than that, I believe CR-39 has better optical quality over higher index lenses.


sourgrapes 27 Feb 2008, 11:32

The easiest way is to ask them to give you the prescription along with your PD and buy what you want online. You can explain you want to do this because it's must cheaper to buy online than to buy locally.

GlassesLover 27 Feb 2008, 11:28

I'm going in for an exam and new glasses on Monday and I have a question on lenses. My current glasses are about 5 years old and are -3.50. My contacts that are about 1 year old are -4.50...I've been having trouble seeing again and am going in for new glasses and contacts. I suspect I'll probably be around -5.0 to -5.50. I really like my glasses/lenses to be thick...what type of lenses can I request? CR39? How would I make this request without sounding like a complete wierdo? Would getting the edges polished be agood idea? Any help is greatly appreciated. Thanks in advance!

Clare 27 Feb 2008, 11:12

Cactus, can I ask you a question please?

My mother, who is a hyperope/presbyope, says that things look 'bigger' with her glasses on. I assume that's because her glasses magnify not that she really sees thing bigger. Is this phenomenon the exact opposite of minus lenses making things look smaller? Things looking bigger sounds very inconvenient. Even the cat looks bigger apparently!

Patrick B 27 Feb 2008, 09:50

Cactus Jack is spot on with his analysis, as usual. I'm sure everyone has noticed how often you can detect somebody looking at you from a car which has pulled up alongside of your own even though you haven't actually seen the person doing the looking. You're simply aware of a motion and need to turn your head to observe the details, and those details usually mean that somebody has turned to look at you. It's almost a bit spooky and probably goes back to some early evolutionary time. With myodiscs or any other high minus lens, you will probably notice that the wearer will usually move his head more to see something to the side so that his eyes won't move from the center of the lens which provides the maximum visual correction. Yesterday, while shopping, I saw a guy with about -12s who probably was unaware just how much he moved his head around to see items on various store shelves. I try to scan things in a more "cosmetically correct" way by going across one row at a time rather than doing a scattershot approach which exaggerates the phenomenon and reveals one's visual problems to those in the know. What vanity!

Cactus is also right that peripheral vision isn't where one gets 20/20, that site being the macula. Hence, people who suffer from macular degeneration have compromised central vision but do retain the less desirable peripheral vision.

Cactus Jack 27 Feb 2008, 09:01

Please add to the last sentence of my previous post - "not identify it upon initially detecting the motion."


Cactus Jack 27 Feb 2008, 08:57


Peripheral visual acuity is not particularly good even in people with "normal" vision. The retina has the best acuity and color sensitivity in the central area and the periphery is primarily good for detecting motion (threats intruding from the side) which is a good survival skill. If you want to evaluate the threat, you HAVE to turn your eyes or head to look at it with your central vision. A common test for peripheral vision is for the examiner to wiggle his finger or a pencil around the edges of the visual field. You are not even asked to identify what he is moving only if you can detect the motion.

Curiously, up to a point, wearing high minus glasses may actually improve peripheral vision some because the minimization effect is very similar to the effect of a wide angle lens on a camera. The minimization moves more of the image toward the center high acuity area of the retina.

People who have to wear high plus lenses do no usually have as good peripheral vision because their glasses tend to act like telephoto lenses with a larger image on the retina and narrow field of view, but again, the important thing is to recognize a potential threat so you can look and evaluate it, not identify it.


Charles 27 Feb 2008, 08:25

PatrickB is quite right in saying that lenticular lenses (myodiscs) do not, necessarily, hamper driving. Until my myopia reached the point where my acuity fell below the required level for driving, I drove without difficulty (or accident) with lenticular lenses that had bowls which, I seem to remember, were 22mm in diameter.

Yes patrick, my 'bowls' are on plano carriers which are hardly 2mm thick. Consequently, they are very light in weight and, therefore, comfortable to wear.

sourgrapes 27 Feb 2008, 08:12

P.S. I don't know how much that has do with with the Rx. It seems like the lenses themselves are not very wide, as well.

sourgrapes 27 Feb 2008, 08:10

Yeah. I don't really have much peripheral vision with my -9's. I can drive just fine, though.

Patrick B 27 Feb 2008, 03:01

Diva: 20/40 is the standard people need to meet in most places to be able to drive legally. Peripheral vision isn't measured as a condition of getting a license. If it were, it would mean that most persons who presently wear glasses wouldn't be able to drive. Frankly, the uncorrected visual acuity of somebody who wears myodiscs at -20 isn't all that much different from somebody who wears -10s. 28mm bowls are a great size for a "driving" pair of eyeglasses and provide a very full viewing zone. I have a pair myself, although my corrected visual acuity with glasses is no longer 20/40 as my myopia has increased.

Bowl size, in answer to an earlier question, is determined by a number of factors including wearer preference and the type of carrier employed. I prefer the negative carriers since they provide a more seamless look across the entire lens, although the edges are thicker than that produced by a plus carrier. I believe that Charles has a plano carrier for his -30s. My day-to-day glasses have 20mm bowls.

Hope that answers some concerns.

diva 26 Feb 2008, 23:08

Not to be offensive, but how would other road users feel if they knew your peripheral vision (as I understand it) is negligible?

I know I wouldn't be happy!

It seems incredibly dangerous.

MyoUser 26 Feb 2008, 22:27

Not at all ! myodisc bowl of 28mm is perfect for driving - it's a question of adaption !!!

LikeGlass 26 Feb 2008, 17:37

Stingray, the size of the bowl also determines the depth of the bowl. as the lens must be thicker than the depth of the bowl, the diameter becomes limited by the lens thickness. As for driving, the nature of the lens produces a "tunnel vision" effect, do for driving, you couldn't really use it.

guest 26 Feb 2008, 11:11

She seems to be happy with myodiscs ! And in my opinion these myos from optical4less really look perfect and really much weaker than they are

Stingray 26 Feb 2008, 09:13

Many of the discussions here on eyescene concern myodisc lenses. I think in my entire life of 50 plus years I can only recall about 2-3 people with such lenses. I am curious about them. At what point in a person's prescription are they an absolute requirement with no other option? Also why would anyone not opt for the blended myodisc as they appear to be more cosmetically appealing? Who decides the size of the "bowl"? I would think the larger the bowl, the more visual area you would have. Obviously, the carrier is worthless and doesn't supply any kind of correctional aid to the myodisc wearer. Why is it that a myodisc wearer cannot wear these glasses for driving?

Jill 13 Feb 2008, 23:21

Yes, same deal for me with glasses with no AR coating. I sent the glasses back to get the AR coating. That's what I get for being cheap, I guess.

lazysiow 12 Feb 2008, 00:07

That sounds really weird as the pairs I get without the AR coating are like that. I have one pair that I now really like the frame on but don't have any AR coating on because i forgot to specify it. Its easily my least favourite pair to wear because it gets fogged up very quickly, there is more glare, harder to clean and having to do it ocnstantly etc.

Jill 11 Feb 2008, 21:13

I just got the lens in an old pair of glasses replaced and I got high index with no AR coating. My eyes look kind of cloudy behind the lens compared to my glasses with AR coating. In fact, I tried rubbing the lens with a cloth when I first got them because I thought they were dusty. Is this common and is the glare that significant? My presciption is:

L: -7, -.25, 075

R: -5, -.50, 090

Despite being high index, these lens are pretty thick (being that they are in a thin metal frame).

LikeGlass 11 Feb 2008, 18:08

Odd problem this person had with the lenses. Just thought I'd post it as someone was talking about this a couple of months ago:

Guest 20 Dec 2007, 17:32

Thanks for your replies. Contact lenses are problem because I have dry eyes. Interestingly, I asked my optometrist regading the abbe value of the zeiss lens. She told me it is 42 but increases to 58 due to the lens coating. She also said it has basically the same optical quality with a cr-39. Is this possible?

DWV 20 Dec 2007, 00:56

And choose a frame with small lenses that are centered as near as possible on your eyes. That will reduce edge thickness considerably, since it increases proportionally to the square of diameter.

Cactus Jack 19 Dec 2007, 19:43


If you can deal with the lens thickness, it is hard to beat CR-39 in a plastic lens. The optical characterics of CR-39 are almost as good as glass.

Another very strange sounding solution is to correct most of your sphere refractive error with low cost sphere only contacts and fine tune the rest of the sphere and all the cylinder with glasses. Yes, it is GOC.

I have used this solution, with an open minded OD's blessing, for several years to fine tune a high prism Rx and achieved better than 20/20. Which I had been told couldn't be done in that Rx.

If you are interested in "how to", let me know.


Trent 19 Dec 2007, 18:27

Hi Guest

Yes I have the same problem. With my high-index lenses I have the same problem. There is one clear spot in the middle of the lens about the size of a pea where I have good vision, around this area the image is distorted. I tried 1.7 index lenses before and returned them because of the distortion!

Best solution is to go to a low index lens in a plastic frame which will hide some of the thickness. Try this in your next pair of spare glasses. Glass lenses have the best optics but are difficult to find these days.

Guest 19 Dec 2007, 17:43

Hi, what lens has the largest clear center? My Rx is (R) -10.00 -.75cyl (L) -11.00 -1.00cyl. Current glasses is Zeiss 1.67 and Hoya 1.71 for backup. I find it difficult using a small clear spot. Thanks.

lentifan 16 Dec 2007, 03:41


Isn't it a pity that medical science hasn't yet progressed to transplanting eyes, as they have with other organs?

If they had, some of us would gladly have offered to swap with you. There might even have been competition!

You may not want to post your pictures wearing your 'thick, heavy' glasses but we'd love to see pictures at least of your glasses.

-32Tony 16 Dec 2007, 01:20

Hi everybody. I am new to this website and I am looking for some help.I am fed up with my heavy glasses and I am looking for contact lenses about -30/ -32 dptr. Does anybody know online retailer offering this. Thank you for your help beforehand.


Lisa 26 Nov 2007, 09:53

Thanks. Now, I'll be less self-conscious!

Genchan 25 Nov 2007, 10:52


I'm sure that at your rx how much extra thickness you will get won't be much at all. Sense Your a base In as well while you will get a mm or 2 extra on the inside edge the outside edges won't get thicker at all, they should actually be a little thiner. Ether way though sense your almost around -2 weeker then me it's not likely at all that your glasses will be as thick as mine, even with the extra 1D prism.

Sense as well it's a low amount of prism as well it'll be more then likely that you will be the only one who will notice any extra thickness and that's only before you put them on. To most people looking at you wearing them their won't be no diffrence at all.

Hope what's been said here is helpfull for you and Good luck with the new glasses and I hope they work well for you.

lisa 25 Nov 2007, 10:05

Hi, I'm about -3. The prisms are base-in.

Roy 25 Nov 2007, 07:29


I agree with your comment that prism wearers seem quite rare. Does anyone know what percentage of glasses prescribed have prism correction? After my last eye test the dispensing optician picked up my prescription and said "Oh a prism, I haven't seen one of those for a while, especially this strong".

I'm well into the varifocal age now and initially had quite some trouble finding an optician that will prescribe varifocals with my prism. I don't know why this is as I get on really well with them once I found an optician who would supply, and have had several perfect pairs since.

Has anyone with prisms tried to buy glasses on line. Some sites can offer prisms (though not usually up to the strength of my prescription) and some offer varifocals, but vitually none seem to offer the combination of both.

Roy 25 Nov 2007, 07:13


As Genchan said the thickness depends on the rest of the prescription. Your lenses will be slightly thicker on the inside edges and slightly thinner on the outside edge than they would be without the prism correction. However with only 2 prism dioptres in each eye the difference would be small. I would estimate that the inner edges might be around 1mm thicker, and the outer edges around 1mm thinner but it depends on the rest of the prescription, the frame size, PD and the refractive index of the lens material. Nobody looking at your glasses is likely to notice anything different about your glasses with the prisms added. I have a much stronger prism in my glasses (10 base out right eye and 8 base out left eye) combined with a myopic correction of 4 dioptres right eye and 6.5 dioptres left eye and my lenses are up to 11mm thick on the outside edges but only 3-4mm on the inside edges. I have been wearing prisms for 40 years but can still remember how magically they cured my double vision when they were first prescribed. I can't remember what my first prism prescription was. I know it increased a bit in the early years. (I could tell when an increase was needed when my eyes struggled to work together again.) It has now been stable for many years and gives me no problems. Surgery is sometimes an option for squint but was never suggested to me and I am glad that it wasn't as I am 100% happy with the glasses solution.

Genchan 24 Nov 2007, 15:59


To have an idea of how thick they will be depends on how strong your rx is without the prisms and also where on the lens you have them, i.e. are they base out (BO) or base in (BI).

I've had them for a few months now with a -4.75 distance correction with 1BO on one eye and 1BO with 1BU (base up) on the other. In a medium size frame my lenses on the outside edge where it shows is about 7mm so quite thick yeah, but at the same time while it shows it's still far from massive. saying that though the inside edge where their isn't anything is around 4mm. a little thinner then before I got prisms.

If you can reply back with more details to what your rx is that will be a great help with answering your question. Try not to worry too much about the thickness though. After all, their job is to help you see better and if their doing that then that's what’s most important.

If you don't mind talking about it though I'd be really interested in hearing why you've been given them. It seems prism wearers aren’t too easy to come across sometimes and it'll be nice to share and compare experances.

lisa 24 Nov 2007, 15:03

Has anyone here ever worn prisms? Been prescribed prisms of 2 degrees in left and right eye. how thick will my lenses be? my left eye squints.

Guest 04 Nov 2007, 01:58

I am -6ish and switch between them all the time. The trifocals provide a much larger near field than the progressives, and that can be most desirable depending on use and occupation. I even have a pair of near script glasses for reading and doing any kind of work overhead.

DWV 03 Nov 2007, 22:26

There is a risk that you'll see better through the bi or trifocals, and come to prefer them.

Curt 03 Nov 2007, 16:47

It is generally no big deal. If you are used to wearing pogressives, the biggest issue is image jump when you transition from the distance portion to the add. I have several pairs of each and wear them interchangeably.

Rupert 03 Nov 2007, 11:32

I recently started wearing bifocals and got a pair of progressives. They're working well, and I'm generally pleased. However, I've always been fascinated by lined bifocals, and thought it would be cool to get a pair as a spare--why spend all the money for progressives? I'm wondering, now that I'm totally adjusted to the progressives, if having a lined pair would be a mistake. How easy is it to switch between the two? Any thoughts?

I'm -4.50 in both eyes, with -.25 of astigmatism.


RL 23 Oct 2007, 07:58

One other thing: My glasses are high index bi-concave, with a -3 base curve on the front and the rest of the prescription on the back. This results in a lens thinner than the ones with a +.50 base. 8 mm at the edges as opposed to 11 mm in a 52 mm frame. Lighter too, and great vision as well.

RL 23 Oct 2007, 06:29

Someone posted to one of the threads asking if folks liked glasses with a big difference in prescription between the lenses. Since my exact prescription is R -11.00, -.50 X 017,

L -14.75, -.25 X 005; the total difference between the lenses is 3.5 diopters. A small percentage of the total, but still noticible. I think it results in a slightly exotic look and have decided I like it, since I have no other choice anyway.

Nemo 16 Oct 2007, 02:46

Phil - and I wish I was -4 and not -5! An inch or two more for reading distance would make reading without glasses comfortable. Now I feel like I have to get too close when reading in bed etc.

Phil 15 Oct 2007, 06:18

With my rx having increased over the last few years after a previous period of stability I have just ordered a some rimless frames with an extra .25 of minus (1.6 lenses).

In July I went up by -.5 to -4 in both eyes. I recently tried on my old specs and everything seemed so dim. I'm actually not enjoying the same sharpness I had initially with the new glasses. So I thought I'd give some -4.25s a go. I've never had a fully rimless pair before: it's quite exciting!

I think I'm going to be edging upwards a bit further, though I've no idea why. I'd be happy to get to around -5 or 6. I'd then have no choice but to wear fulltime! And the rx would look serious but not too distorting. Wish I'd forced it higher years ago!

Cactus Jack 12 Oct 2007, 18:06


Sometimes the inside edge of a lens with prism will be about 1 mm thick. The thickness of the outside edge is a function of the Rx, the width of the lens, and index of the lens material. Unfortunately, the cutrrent fashion in lenses is rectangular which results in thick inside and outside edges.

I did not mean to imply that contacts are out of the question. If you become very worried about lens thickness, the glasses over contacts solution would not be out of the question. Though if your optician doesn't have any imagination, it may cause a heart attack.

Your current Rx is:

OD -3.25, -1.50 x 95 BO 3

OS -2.75, -0.75 x 105 BO 3

You could wear this combination or something similar

Contact Lens

OD -3.25

OS -2.75


OD 0.00, -1.50 x 95 BO 3

OS 0.00, -0.75 x 105 BO 3

You could even wear a bit more minus in the contacts and some plus sphere in the glasses which would make the edges even thinner, even with prism.

Modern soft contacts are very comfortable and sphere only contacts are very inexpensive.

One thing I would lile to suggest, don't get too hung up on the thickness of your glasses. Seeing well and comfortably is the goal and a good choice of frames can significantly enhance your attractiveness no matter how thick the lenses. Though some guys are very attracted to thick glasses.

Another question, may I ask where you live? (Country)


Bywater 12 Oct 2007, 16:42

Hiya CJ. You are great! I feel better knowing that prisms aren't addictive. But I'm worried about the increase in thickness of my glasses. The right lens is already about 5mm thick and the left about 3mm. Also, the inside of my right lens is thin already, less than 3mm, as is the left, so how can the inside lose almost in thickness?

Anyway, looks like I won't be getting contacts sometime soon. Bye.

PS: I'm a girl. You said sometimes they increase the prism? Does that make a difference to what might happen?

Cactus Jack 12 Oct 2007, 15:54


A lot of stuff about prism is a myth. You can get used to wearing prism in the same way you can get used to wearing glasses - comfort. Comfort in all forms is highly addictive.

There is usually a reason you need some prism. I your case it is likely, as I said, that your inside muscles are stronger than your outside muscles and try to make your eyes turn inward just a tiny amount. To keep your eyes straignt without prism in your glasses, the outside muscles are having to constantly pull against the inside muscles and after a while the outside muscles get tired and sometime start to complain - particularly if the inside muscles are very strong.

Were you having any problems with double vision or headaches?

With the tiny amount of prism prescribed, I suspect that you may not have had any noticable symptoms. The examiner may have discovered a problem when he caused you to see two rows of letters with one above the other but offset horizontally, and asked to tell him when the letters were exactly aligned one above the other. He found that you needed some base out prism to align them properly.

There are several forms of this condition and the most common is Esophoria - maning that your eyes want to turn inward, but you can hold them straight with effort. There is another form called Esotropia - meaning that your eyes turn inward, but you can't straighten them (crossed eyes or squint in some countries).

In many ways, Esophoria is like hyperopia where the ciliary muscles can focus close up, but are having to work hard to do it. Hyperopes finally get glasses, but it takes a while for the muscles and crystaline lenes to fully relax and then the Rx has to be increased and they have to go to full time wear. Sometimes prism is like that as the positioning muscles relax and you need a bit more prism. If you get to where you need a lot of prism, the problem can be corrected with minor surgery on the eye muscles.

To answer your question about contacts with prism. Theoretically, prism could be put in contacts, but the problem is, that for it to work properly, the base of the prism must remain exactly where it is supposed to and you can't guarantee that in contacts. You could wear contacts to correct myopia, but you would have to wear glasses with the prism. A form of Glasses over Contacts. In your case, you have enough astigmatism that you would need toric contacts, but they are more costly than sphere only contacts and some people have trouble keeping them where they belong on the cornea. Of course you could wear sphere only contacts to correct your myopia and glasses with cylinder for your astigmatism and prism.

The simple and cheap thing is to wear glasses.

May I ask your gender?


Bywater 12 Oct 2007, 14:47

Hi again. Thanks for the explanation Cactus Jack. I get it now. Another question: I've been reading up on here and someone said you get used to prism lenses you can't stop wearing them because your eyes sort of adjust permanently in that position, or something. Is that right?

Also that you can't wear contact lenses. I've never worn contacts, but I was wondering about that. Thanks again.

Cactus Jack 12 Oct 2007, 13:23


Should be 'edge of a prism'. Sorry about any typos.


Cactus Jack 12 Oct 2007, 13:21


Prisms are used to bend light rays. If you look at the eger of a prism it looks like a triangle with a short base and long sides. Sort of like a slice of cake or pie.

For optical purposes, prism is used to help correct muscle balance problems and conditions like your where your eyes try to converge or "cross" slighly.

It is normal for your eyes to converge when focusing up close. If they didn't you would see double when you tried to read. When looking at distant objects each eye mormally points straight ahead and the lines of vision from each eye are parallel. If they are not parallel, you will see distant objects, double.

Apparently, your eyes have a tendency to converge slightly and the eye muscles that move your eyes inward are a bit stronger than the muscles that move your eyes outward and they are fighting each other. The Base Out (BO) prism allows your eyes to converge slightly to where the muscles are not fighting and the prisms bends the light rays slightly so that distant objects are not double.

3 prism diopters base out will bend the light rays about 1.5 angular degrees. This small amount of bending will not be very noticeable to you, but will allow your eye muscles to relax and cause less fatigue. The outer edges will be slightly thicker (about 1 mm per prism diopter)and the inner edges will be a bit less than 1 mm per diopter thinner. The actual amount will depend on the width of the lens and the location of the optical center.

Unless someone really understands optics and lenses, they probably will not notice unless they examine the glasses very closely.

I Hope this helps. If you have more questions, let me know.

BTW, prism has nothing to do with the actual power of the lens.


Bywater 12 Oct 2007, 07:13

Hiya. I've just been prescribed something called prism lenses because my eyes don't seem to focus straight ahead very well and I don't know what prisms are. I know I should have asked at the time, but didn't, sorry. Don't seem to be able to find much on the internet either.

I've worn glasses since I was six and I am now 16. My new prescription reads:

OD -3.25 -1.50 95 BO 3

OS -2.75 -0.75 105 BO 3

Does this mean thicker lenses? My actual prescription has only gone up by -0.25 for each eye in the past year, so I thought I was doing OK. Thanks...

ehpc 10 Oct 2007, 07:21

Mnus 22 in square black plastic frames :) That sounds HOT :) Pete

sweetstephine 10 Oct 2007, 06:30

I've recently broke my glasses because I tripped walking in high heels. I was reading a magazine and I slid my glasses down to prevent eye strain , they were lose fitting , and I was walking looking through my -20 lenses at the same time. I tripped on something and fell forward on my hands and knees. My glasses fell off my face immediately and everything went complete blur. I gropped around feeling for my glasses but I couldn't find them at all. I got up and started feeling my way around and stepped on them.I had a spair pair (not as nice looking)and wore them for about a week. It turns out I've had an increase in RX and got some -22 in some black plastic square frames. My old spair pair wasn't up to date so I donated them. I don't mind helping other needy people, but my new glasses just don't fit right and slide a lot.

Charles 28 Sep 2007, 00:48

Patrick B

I, too, have had many experiences of people being helpful when they notice me having a bit of difficulty with relatively everyday things.I used to hate it and, I hope not too brusquely, say that I was 'OK thank, you'. However, in the last 2 or 3 years I have occasionally had to ask for help in seeing bus numbers and street names in unfamiliar places. My biggest problem is in airports where I now frequently have to ask for help - the screens are so small.

Patrick B 26 Sep 2007, 14:34


Peoples' perception of strong glasses runs the gamut from being totally clueless to overwhelming curiosity and, perhaps, sensitivity. I find descending stairs a bit of problem and was "caught" making my way down quite tentatively in a darkened room. A friend of a friend actually took me by the arm worried that I might take a tumble. Charming but disarming. He understood about the need to look straight down through the lenticular bowls since a grandfather of his had had the same problem post-cataract surgery back in the days before sophisticated intraocular lens implants virtually eliminated cataract glasses.

20/50+ really isn't all that hard to deal with, although I had to admit that I was surprised at my visual limitation when, after many decades of 24/7 contact lens wear and never having a fully-updated glasses prescription, I finally got an up-to-the-moment pair and had to admit that I would never again have anything resembling 20/20 vision with glasses. At least I can still wear contacts, although am definitely supposed to give my eyes a rest.

Charles 15 Sep 2007, 04:11

Patrick B

My experience is that my unusual glasses make some people surprised how well I can see with them and so, until they realise that I can see, treat me as though I am practically blind. On the other hand, others are equally surprised at how poor my corrected sight is. As you say, our degree of myopia is less than 1% of the myopic population so why should people have any understanding of it.

Eyesore 15 Sep 2007, 03:29


Julian 14 Sep 2007, 08:44

I went to book a test the other day, in a new place since last time, enquired about Varilux Ellipse or similar, and was assured that narrower progressive lenses are readily available these days.

Patrick B 14 Sep 2007, 08:25


It's great to hear that I'm not the only one in the high myopia boat. There aren't many people with vision worse than -20 (well less than 1% I'm told) and even some of my friends who are pretty myopic at -5/-6 have no idea what an extreme myope goes through. Recently, when I realized that I couldn't read a wine list in a dark restaurant (and had left my readers at home which actually look much more powerful because they aren't lenticulars and are very thick) I passed it to my friend who remarked, as he whipped off his -9s, that I should just do the same or get bifocals. Here he is very myopic himself and clueless that that I can only see about an inch without correction and, on top of that, would have to close one eye to read anything. Not very attractive. It also took some explaining as to why I couldn't have bifocals with lenticular lenses. I guess these blended lenticulars are a cosmetic success because hardly anyone is aware of the bowl behind the biconcave surface and just how much power it contains.

I'm thinking the time is coming to get a small hand-held telescope for that monent (when I'm alone, of course!) when I need to see a bus number or building address.

Russell  14 Sep 2007, 04:14

For future reference, Jess: I sent my frames to, and for $128, I got Varilux ellipse lenses, beautifully made. Although the frames they sell are not that trendy, the lenses are inexpensive and well-made. It took about two weeks, so if you are outside the US, you might have to wait longer than a "walk in" optician, plus the postage would be more. All in all, it would still be a bargain!

Jess 13 Sep 2007, 20:04

I just got ordered my new glasses tonight they will be ready in about 10 day's so I will let you know how I like them I was able to get the new glasses that I wanted but the compact progressive lens was very expensive. Thanks for all of your help i will let you know when I get them

Baker 12 Sep 2007, 14:27

Jess Tuna's suggestion is a good one. SV readers are handy particularly if you like to read in bed.Also in my case I notice that the image is slightly larger than the reading portion than my aspheric progressive lens. . Full sized readers also may loosen accommodation if you still have some latent hyperopia.One downside of being a higher hyperope vs a myope at least in my case... you end up spending a bundle on glasses in the long term. The other suggestion about sv distance with or without bifocals or full strength readers as well is having a pair of backup glasses. The high end progressives can take a while to get made if you break a lens etc.(i've just been there 2, weeks to get a lens replaced from Nikon))

Charles 12 Sep 2007, 10:16

Patrick B

We seem to have very similar eyesight problems. Like you, my acuity is much worse in poor light and I, too, find my most comfortable reading distance is about 6 inches. I only read large print books now, anything else is too much of a strain (like the font size of the post I am now typing) I also make attempts to hide the extent of my myopia - I suppose it goes back to childhood and trying to prove, in spite of getting ever stronger looking glasses, that my sight was as good as anyone's.

tuna 12 Sep 2007, 06:09


Hang on to your current frame - you can use them for single vision lenses in your reading strength - which might end up being your distance RX anyway. SV lenses aren't usually too expensive. And they are handy for intensive work if you have progressives. (tho just use the progressives only for the first few weeks or so in order to train your brain to fully accept them.

Julian 12 Sep 2007, 05:22

...or as a last resort you can sell your present glasses on eBay.

Julian 12 Sep 2007, 05:21

Well Jess, you can still try another optician - or you can settle for lined bifocals till your next new Rx.

Jess 12 Sep 2007, 05:15

They told me that I needed at least 15mm also and they said that the frames that I have will not suppert the lens I need. I guess I have to get new frames again.

Phil 12 Sep 2007, 01:14

Jess, Although it's annoying to have to pay more I think that the more expensive varifocal lenses are far superior. I always had Nikon but tried to save a comparatively small amount by getting a slightly less expensive lense type last year. They were hopeless: they made me feel drunk. I've now reverted to Nikon and the difference is enormous: a much better field of clear vision and no wobbles.

Baker 11 Sep 2007, 19:29

Jess Follow up from previous post. You need to know how many mm from the bottom of the lens to to where your distance starts. eg In my case I needed a lens design that could handle 15mm.There's weren't many lens choices. Your optician should be able to tell you. You also need a good optician because progressives need to be measured by someone that knows what they're doing. Also if you're getting progressives they're great for a computer. With your rx aspherics are pretty neat.

Baker 11 Sep 2007, 19:09

Jess Similar experience. Was told the frame I liked wouldn't take progressives. Another problem Nikon W short corridor lens...expensive though. If you're just starting off get progressives....with your rx you'll appreciate mid-distance down the road. I started with them in my early 30's.

Julian 11 Sep 2007, 18:33

Jess: try another optician. There are progressive lenses (e.g. Varilux Ellipse) that can fit into smaller frames. They might cost more though. Check the web first.

Jess 11 Sep 2007, 16:25

I went to get my Rx put in my glasses today and found out that the Glasses that I have will not take a progressive lens Rx so I either have to get lined bifocals or get new frames. I do not want to get lined bifocals but at the same time my glasses are Armani and they were not cheap, this is my Rx:

R +3.25 add +1.00

L +3.25 -025 x 015 add +1.00

Patrick B 11 Sep 2007, 10:41


Yes, minification is unavoidable no matter how close the lenses are fitted to the eyes. I started to notice it when my prescription started to climb above -10. I think 6/24 is the equivalent of 20/70 which makes your acuity a bit worse than mine which is 20/40 - 50, especially at night. My reading glasses are three diopters less than my distance glasses, although I sometimes pull my distance glasses away from my eyes a bit if I don't have to read much, say a menu. Otherwise it's the readers and then "scanning" the material at about six inches which really reveals the extent of my myopia. I shouldn't be so vain but will almost never push my glasses up against my eyes when I need to see something clearly in the distance if I'm with friends. Silly, really.

Charles 11 Sep 2007, 06:33

Patrick B

One of the factors causing my distance and reading acuity to be poor is minification which I imagine is problem for you, too. Fully corrected, my distance acuity is only 6/24 (3rd line down on a UK eyechart).My reading glasses are -4.00D weaker than my distance ones and I need to be close to what I am reading unless the print is quite large.

As far as it's possible to be happy with the appearance of glasses like mine, I do like the look of these more than 'conventional' ones. Also, they are the lightest lenses I can ever remember having and are very comfortable to wear. The edge thickness of the carriers are only about 2mm and the bowl is app. 8mm and is very close to my eyes which, as you know, is ideal for extreme myopia.

Patrick B 10 Sep 2007, 13:57


I, too, wear a weaker pair to read and have to hold the page closer than would be considered normal. Isn't it funny that even though neither of us has 20/20 fully-corrected, we still can't see to read with our current distance prescriptions. I had also meant to ask you how you liked the look of your lenticulars set in the plano carrier. Are the edges of your bowls fairly thick?

The strongest myodiscs I ever saw were on a young guy in London in the late 70s. The bowls of his lenses probably were no more than 10mm across, if that, and I would estimate that he was well in excess of -30. Of course, those were the pre-high index days. I suspect his vision was quite limited with those glasses, and he had to move his head constantly to see.

Charles 10 Sep 2007, 02:42


Like you, I used to have a lot of distortion which lessened considerably with lenticulars. The last conventional lenses I had were some years ago. They were in a spare pair and were somewhere around -27. The quality of vision I got from them was very poor compared with lenticulars of the same rx. The degree of distortion was was very offputting and, because the lenses couldn't be as close to my eyes, my acuity wasn't as good either. I was told this was due to greater minification.

Even with correction, my acuity is quite poor. As measured in the UK, I am 6/24 (just) which is the 3rd line down. In poor light, my acuity is less than that. I need to wear a weaker pair to read and have to hold print quite close. Unfortunately, I am one of those people whose myopia seems never to stabilise.

Carol 24 08 Sep 2007, 00:04


I think you are right, once you get used to prisms it becomes very hard to manage without that correction.

I went to the hairdresser the other day and had to remove my glasses, i noticed that within about an hour of no glasses i started to feel ill....bit of headache, sort of swimming feeling and the need to close my eyes, once i put my glasses back on it all dissapeared.

I would never have believed that prism could have such an effect in such a short space of time, i have only been wearing them for 10 days.

I am certainly now a full time gwg, glasses are the first thing on in the morning and the last off at night. Before the prisms i used to manage without glasses while at home but now i seem to need them continuously, however they do what they were mrant to and for that i am grateful and more than happy to wear them. I also think i need to get a spare pair as if anything happens to these i may find myself in an awkward situation

PatrickB 07 Sep 2007, 13:39


I'm not that far behind you in prescription! There was a guy who wrote here not long ago who finally "gave in" to myodisc/lenticulars with a plano carrier and was very pleased with the result cosmetically and visually. I think his prescription was over -25, and he had fought getting myodiscs until there was no longer a realistic alternative. Like me, he couldn't believe that he had refused to get them for such a long time. The fear of looking through such a small bowl is so misplaced when one realizes that the effective viewing area of a super-strong conventional lens is the same. Did you find that the switch to myodiscs was accompanied by a decrease in distortion? I certainly did. Perhaps I will try to get plano carriers next time, although I like the negative carrier since the contrast between the negative bowl and the negative carrier makes for a more seamless appearance.

I'm over 50 and can wear contacts with great success. How well do you see with your glasses? I'm probably around 20/30 - 20/40 + depending on ambient lighting and how close I've got them to my eyes. You'd think that at some point one's prescription would stabilize, but for some people it never seems to happen.

Charles 07 Sep 2007, 01:45

PatrickB & RL

I was interested in what you had to say about myodisks (lenticulars here in the UK). I have had them since I was about -23.00 or so. Far superior from the comfort and optical point of view. Unfortunately, a few months ago my rx increased to a little over -30.00. My new lenses were specially made in Germany by Zeiss with 20mm bowls in plano carriers. I think they are cosmetically better than the more conventional type and very much more comfortable to wear as they are so much lighter in weight.

Aubrac 07 Sep 2007, 00:54


It's good to hear that the prisms are working for you and no more headaches.

Since wearing them, what is it like when you take your glasses off? Many people say that once you have started wearing prisms and got used to them, your eyes have great difficulty in readjusting without them.

Are you a morning till night wearer and have you found it very difficult to get around without them now?

Carol 24 05 Sep 2007, 01:44

I have had my new glasses for nearly a week now. I did not notice much difference at first other than the lenses are a lot thicker than my old ones on the outside edge, about 7mm, they have been polished so look nice.

After about 6 hours wear i had an odd feeling of my eyes being ' puuled ' sideways, this lasted for about 4 days and during that time my headaches started to reduce as well.

I have now been wearing them for 6 days and as predicted by the optician and helpful comments from you guys, i no longer have any headaches....the prisms appear to be doing the job.

I have not had any remarks from friends and work, but my mother has said each time i have been to her house ' why are you wearing your glasses all the time, they do look thick '. I really dont think she understands. If prisms work for me , as they seem to be doing , i will gladly have them even if prism correction increases wildly. It is such a relief to know i will only suffer headaches if they are alcohol induced, sounds like a good night out is due. Thanks Carol

Aubrac 04 Sep 2007, 08:11


Does your daughter have any astigmatism correction as this is very often more the reason for headaches than hyperopia.

People with astigmatism without glasses often tend to move their head at an angle to what they are looking at, which compensates in part for the cylinder correction they need.

My wife (although 20 years older) has the same prescription (with -0.75, 130, -0.50, 40 for astigmatism) and is part-time wearer for near and distance.

I don't know if going into contacts straight away for what is still a fairly low scrip is the best option. Suggest she wears her glasses for initially concentrated periods of reading, and then see how it goes.

M 03 Sep 2007, 21:19

Hi all! I posted awhile back on the psyc thread about getting progressives and never followed up. I was told to drastically cut down on my contacts time. Originally I was going to wear my contacts with readers to work and my glasses at home. Well, I got the progressive glasses and hated them. I tried them one weekend and just couldn't stand them. So I kept wearing contacts and only wore the glasses maybe one or two hours tops at home in the nights. After a couple weeks, I finally tolerated them and learned how to walk with them! Stairs and any sort of ledges were interesting. I guess I never noticed how dry and tired my eyes feel with contacts, I mean I thought that was normal after 20+ years. They don't now when I wear my glasses at night. By the way, I was worried about them being thick but between the plastic frames and expensive lenses they don't look thick, they look strong if you look threw them but not thick. And they shrink my face a little behind them. The best part is my husband doesn't care at all, he has never commented about me wearing them or not. Its just business as usual. I haven't mustered up enough courage to wear them to work, but have worn them out to dinner a few times and shopping. I guess I'm using them about 1/4 of the time and maybe I'll wear em to work sometime, but actually I don't know if they'd be practical because I work on computer a lot and the narrowness of the bottom section might bug me.

Tod 03 Sep 2007, 11:41

Carol 24,

True contacts, at least soft ones don't provide for prism correction [I am not sure about RGP lenses] But if its the case, why not wear contacts for myopia correction only, then have prism correction only put into glasses so you can take off the glasses when you want to. Also, have the prism only Rx put into sunglasses. Have the regular glasses with a nice rose colored tint.

Tod 03 Sep 2007, 11:38

True contacts, at least soft ones don't provide for prism correction [I am not sure about RGP lenses] But if its the case, why not wear contacts for myopoa correction only, then have prism correction only put into glasses so you can take off the glasses when you want to. Also, have the prism only Rx put into sunglasses. Have the regular glasses with a nice rose colored tint.

Good luck!

Tod 03 Sep 2007, 11:29

Carol 24, why do you think you are having trouble with your contact lenses?

Could it be an out of date prescription or maybe something is wrong with the lenses themselves, such a warping.

daisy 03 Sep 2007, 11:14


Why don't you get your daughter some contacts? She obviously needs correction. I know I would have headaches w/out correction.....and if she is not comfortable in specs, get her some cls for crying out loud!

Patrick B 03 Sep 2007, 08:29

Cactus Jack:

Yes, my glass lenses are a bit heavier with the glass but the enhanced optics more than compensate for the extra weight. They're still not as heavy as my old plastic lenses from the 80s which were really thick even though my prescription was "only" in the mid-teens. Glass lenses are hard to get in the States but easily available in Asia/Europe/Canada without a special prescription. For me, they're the only option I now have if I want to have reasonable visual clairty (20/30 or 40) without having to wear contact lenses

chrisb 02 Sep 2007, 14:53

Management of Latent Hyperopia.

all, my daughter who is approaching 17 has just had her second bi-annual examination and prescription. Talking to the optician after the examination she has latent hyperopia of about 1.75 and 1.5. This has gone up slightly since her last examination, but the optician feels she has stabilised. Putting aside any questions of cosmetic and style, would she benefit from full time wear. She complains of headaches and tiredness when reading but has resisted wearing her first prescription at all.

My theory is that at nearly +2 she would benefit, as the range of accomodation between her near vision and her distance vision would be reduced??

Your thoughts and suggestions? That's not to say of course she will adopt full time wear if I suggest it.

Patrick B 02 Sep 2007, 11:43

RL - I have negative carriers which I really like. Although they are thicker at the edges, I like the way they look cosmetically since both carrier and bowl are negative thereby eliminating the sharp contrast between the minus and the plus portion of the lens. Second, when my eyes stray from the bowl I can still see something; it isn't just a complete blur.

Actually, I got them at Optical4Less. I speced them out since I believe their default lens type is a plus. With the small frames and the blended bowl they look far less powerful than my old ones. Clearly, they appear strong to anyone who knows anything about glasses, but the average person only notices edge thickness.

Let us know what you do.

RL 02 Sep 2007, 11:04

Patrick B,

I have had myodiscs with 28mm bowls and a plus carrier. I agree, the distortion is less than with other lens types, even at -15. I have tried to find myos with a plano carrier and have had little luck. Where did you find yours and what kind of carrier do they have? Thanks for the info.

Cactus Jack 01 Sep 2007, 12:15

Oops! Sorry Patrick B.


Cactus Jack 01 Sep 2007, 12:14

Batric B.,

Optical Glass has superb optical properties. The only problem is that it is heavy, expensive, fragile, and very few people know how to work with it any more. Safety considerations also play a role. It is unfortunate, that glass seems to be reserved only for those situations where there is almost no other choice.


Patrick B 01 Sep 2007, 11:51

RL and Cactus Jack:

The last pair of glasses that I had that weren't myodiscs had 1.7 high-index glass lenses with -4 in the front and the balance of the -23/-24 prescription in the back. The frame was quite small and the edge thickness had been beveled off quite a bit creating a pseudo-myodisc effect. I really loved the glass lenses (which fitted right up to my eyes) since they really seemed to provide better optics than any of the plastic lenses. They were even better after I had the beveled part polished which somehow enhanced the refractive properties of the lenses. (Perhaps by admitting more light.) My next pair (-24/-25) were 1.8 Zeiss glass myodiscs with -3 of the prescrition in the front, and my current ones (-25.5/-26) are also myodiscs with 20mm bowls. Should've gone with the myodiscs years ago since I find them to be less prone to distortion.

RL 29 Aug 2007, 19:52


I found an old CL prescription. They were -13.25 at the time. 1998.

Cactus Jack 29 Aug 2007, 19:26


The only reason I asked about the contacts is to get an idea of what your ECP prescribed for lenses with a zero vertex distance. It is great that you have found a solution that gives you excellent acuity.


RL 29 Aug 2007, 15:41


I do not have a contact lens prescription. Wore them for 25 years. Now, I find them annoying, so I stick with glasses, and I see better than 20/20.

Cactus Jack 29 Aug 2007, 11:29


If you were refracted at -15, the vertex distance of the phropter was probably about 10-12 mm. If your glasses are actually that close, the effective power is probably about -16 to -16.50. Do you also have an Rx for cotnacts?


RL 29 Aug 2007, 10:49


Sounds like a pretty good explanation. The glasses do fit very close to my eyes, so close in fact, that I can't get the tip of my little finger between the lens and my eye and my eyelashes rub on the lens. This probably makes the vertex distance something like 5mm. So, I'm likely getting some help there.

Cactus Jack 28 Aug 2007, 22:05

Oops! It should be


Cactus Jack 28 Aug 2007, 22:03


I will ask you to take this answer with skepticism. It is what some people call a SWAG. Only this one isn’t very sophisticated.

If your RX is -15 and -3 of that is in the front surface of the lens the remaining -12 must be in the rear surface. With an Rx of -15, the effects of vertex distance is about 0.225 Diopters per mm or nearly 0.25 D. One explanation might be that the reduced rear surface curvature allows a reduced vertex distance between the rear surface of the glasses and your cornea, which would result in a slightly larger image on the retina. That should give you slightly better acuity because the image elements are spread over more rods and cones of the retina.

Hopefully, some of our professionals will offer a better explanation and critique this answer.

If you need an explanation of SWAG, please contact me at


RL 28 Aug 2007, 19:24

Question for Cactus Jack, or anyone else who may know. My prescription is -15.00 with only -.50 astigmatism. Over the years I have had every imaginable lens, including hi-index 1.74. But regardless of lens or lens material, my ideal base curve is -3. This results in the very best image, and the image with -3 appears to be slightly larger than with plano or any of the positive base curves. I have never gotten an answer for why this is, and would like very much to know.

carol 24 26 Aug 2007, 01:07

Roy , likeglass , specs4,

Thanks for all your helpful comments, i have this week been back to the opticians and orderedmy new glasses.I decided not to go for a really small frame as i prefer a slightly larger lense size ,i find it gives a better all round view. Iasked the optician about the lense thickness and was told with the frames i have chosen it will be about 7mm ,but she did say she would have the edges polished. Glasses should be ready on Wednesday, meanwhile i am still suffering the headaches so actually i am looking forward to new glasses, if only so they do as expected.

Thanks Carol

Roy 20 Aug 2007, 12:37


I have had prisms in my glasses since my twenties, with a myopic correction. I can remember the problems I had with headaches, some double vision, and a strange difficulty in keeping the eyes working together. The optician did some extra tests and prescribed base-out prisms which instantly cured all the problems. I have worn them ever since.

With 3 b/o the extra lens thickness will not be much, perhaps 1-2mm depending on the frame size, and the appearance of the glasses will not be noticeably changed. I would suggest trying the prisms. I believe it is true that prisms cannot be incorporated into contact lenses.

LikeGlass 19 Aug 2007, 17:54

There is a bit of controversy regarding prism. Your eyes don't want to point in the same direction so the prism allows them to not have to. The problem is that it's a bit of a muscle thing as compared to a refractive error. Unless your eyes have always been that way, this would indicate that there is an imbalance in the muscles that aim your eyes. This may (and I repeat may) be helped with exercise. Now, let me balance this out with the fact that I have a somewhat negative bias against doctors that seem to fast to "prescribe" as compared to "work with." (pills, tests, glasses, etc.) If they give you relief and you are happy, go with it. A second medical opinion may help if you don't like the current option. The concern that goes through my mind is that by getting the muscle "off the hook", it has no reason to get stronger, and may infact get weaker.

specs4ever 19 Aug 2007, 12:18

Nope, she is telling you the truth. Your glasses will be quite a bit thicker looking at the outer edges. And with the prism, you will get headaches if you try to go without them. Sorry, but all you can do is get yourself a frame you like, and spend the extra money on a higher index pair of lenses, if the idea is there that the thickness will bother you. And just remember ;-) a recent survey tells us that 62% of men find girls who wear glasses to be attracive.

Carol 24 18 Aug 2007, 23:31

Afriend told me about this site, i have been reading posts and found it all very interesting.I went for eye test yesterday,i am mildly myopic R -2.25 - 1.00 55 L -3.00 -.75 90 I have recently been getting headaches towards the end of the day and mentioned this to my optician. I have been given new prescription R -2.50 -100 55 3 b/o prism L -3.25 -.75 90 3b/o prism. She said i now need to be wearing full time and i will find the prism stops headaches....but if i try to go bare eyed or use my contacts a headache will rapidly appear, also she told me to choose a small frame as the lenses will be a lot thicker than old ones.This is quite a shock to me, i dont dislike wearing glasses but it seems i must now resign myself to be a gwg for the rest of my life and i am not too pleased with having to dump my contacts. Is this correct or is my optician just giving me worse case scenario. Thanks Carol

stingray 17 Aug 2007, 11:56

Actually, I did some research and did find out what it is used for. It's made of 2 concave lenses in a magnifying glass holder. Since it reduces the image from the strong lens (approx -6.00D) It is used by commericial artist and quilt makers to get an idea how their item or quilt would look smaller. So If you were making a quilt and wanted to get an idea of how it would look, you would hold up this glass and see a smaller, but a complete image of the item. Would also work as a single eyeglass lens too I guess.

LikeGlass 17 Aug 2007, 11:18

ahhh... putting out the small fires you start with a magnifying glass ?


Maybe, if it's old, they used to sell them for nearsighted people to use for reading. Who knows!

As a farsighted person, I can walk into any drugstore and grab a pair of glasses in a pinch. I've always thought it was unfair that nearsighted people did not have the same option. I guess we are so hung up on doctors that people are afraid of lawsuits or something, but lets face it, wouldn't it be great to get something over the counter in a pinch instead of walking into walls, even if it wasn't perfect?

stingray 17 Aug 2007, 11:08

At a yard sale I bought a Bauch & Lomb Reducing Glass...the opposite of a magnifying glass. Does anyone know what this was used for?

LikeGlass 13 Aug 2007, 07:59

Oops! That was me!

 13 Aug 2007, 07:58

"Driving Glasses" are often very low in the RX, or sometimes only a small Astig. The problem I would see would be the resale value of the car! I can see the ad now:

07 Mini Cooper:

Low Mileage, 5 speed tran, 2 door, red

bucket seats, GT pack, FM/Sat/CD

-.5 rx windshield

VFL 12 Aug 2007, 00:16

Fred Flintstone's boss in a long-ago episode offered to have a prescription windshield installed in a bus or truck or some-kinda vehicle if he would just stay with the job... once...

I remember from when I was a kid in the '60's. (Ya know how this glasses stuff started back then according to Sigmund Freud.)

Love and kisses from VFL who is wearing her glasses as she types this.

DWV 11 Aug 2007, 19:30

"Yuen-Ming" claimed to have a prescription windshield.

Edge thickness goes up as the square of diameter. But, maybe with a mild prescription, a very small windshield like those on old-time roadsters that just protected the driver's face, and a high-index plastic lens, it could work.

Stingray 11 Aug 2007, 17:16

The concept of a corrective windshield is wonderful idea as long as you drive straight and never check your side view and rear view mirrors. Also, how would you see your instrument panel.

myopeinhere 11 Aug 2007, 07:58

hmmmm,think billy Connolly got there first

skeptic 11 Aug 2007, 07:38

The windshield would be incredibly thick with that size of a lens.

cut-in UK  11 Aug 2007, 02:25

With apologies to Wiliam Heath Robinson, and expanding Julian's point about the vertex distance, technically the idea could not work because the VD is SO great, and constantly varying. The 'lens', be it fresnel or conventional, could not interact correctly with the eye(s) of the driver.

Nice theory though !

Julian 10 Aug 2007, 23:18

I've heard of the idea, but for one thing, that makes one hell of a vertex distance; and for another what happens when the car goes in for service and a mechanic has to drive it?

Flinkodenia 10 Aug 2007, 21:01

I just saw a video about a new car windshield that is actually a large lens made up in car owner's eyglass prescription. The driver only needs glasses for driving, so he had the windshield made to correct his distance vision while driving.


specs4ever 29 Jul 2007, 10:56

I should have mentioned Clare that the posting from Cactus Jack was to tansbourne and was part 2 of an earlier posting today - 17:49 was the time I think

specs4ever 29 Jul 2007, 10:54

A very small amount of astigmatism will not be very noticable Clare. However, even a tiny amount of astigmatism will, when corrected, give you much better vision. A good explaination of why is available in Cactus Jack's recent posting

Clare 29 Jul 2007, 07:56

specs4ever - would the angle of astimatism affect the look too?

I have a very small amount of what I understand is oblique astimatism, which is diagonal rather than vertical or horizontal, and I read that that type needs to be corrected more than the other two. Even though it's only -0.25, at my last CL check-up it made a noticeable difference between the eye with versus the eye without astigmatism. I thought -0.25 was so small as to be virtually unnoticeable so that came as quite a surprise.

specs4ever 28 Jul 2007, 12:29

It depends on the degree of astigmatism Leon. A -3.50D lens with -0.25 of astigmatism on a 90 degree axis would indeed be the same thickness at the outer edge as a -3.75D lens. But a -3.50D lens with the -0.25D of cyl on a 180 degree axis would only be as thick at the outer edge as a -3.50D lens(although the top and bottom of the lens would now match a -3.75D lens. Hope this explains it for you.

Leon 28 Jul 2007, 11:57

Question: what effect does a -0.25 cylinder have on lens thickness?

Would a -3.75 lens be just as thick as a -3.50 -0.25 lens?

Clare 17 Jul 2007, 12:07

Cactus Jack - do you know what affects the appearance of similar lenses? My friend is -2.75 but her lenses look much stronger than mine (-2.75 and -3 with -0.25 cyl).

I have 1.67 index (overkill I've heard but I like thin lenses), can you guess why hers look stronger? I haven't asked but her contacts aren't torics so I'm guessing it's not to do with astigmatism.


Cactus Jack 16 Jul 2007, 19:53

glassesfor everyone also for Lydia,

"Power Rings" are actually internal reflections of the edges of the lens.

Caution, this is going to get a little deep!

Lenses can be thought of as in infinite number of infintesimally thin prisms aranged around the optical center of the lens. For minus lenses, the bases of the prisms are on the outside of the lens away from the optical center. For plus lenses, the bases of the prisms are arranged around the optical center of the lens. Prisms deflect rays of light in addition to separating the colors and lenses accomplish the same thing.

When the power of a minus lens is increased, the edge (base of the prism) gets thicker and there is more surface to reflect. Also the lower the index, the thicker the edge. The type of edge finishing and the method of mounting the lens in the frame can add interesting effects to the "rings".

You can prove that the "rings" are in fact reflections of the edge by looking from the front of the lens and putting your finger against the thick edge and noting the slight change in the appearance of the "rings" (you may have to lick your finger first to get good contact).

Power rings can be minimized by a very slight tint and almost eliminated by finishing the edge in a flat black non-reflective coating. Polishing the edges adds some interesting jewel like effects. Frosted edges make the most obvious power rings..

Base out prism in a minus lens offers some very significant effects of thick ringes at the outer edges and almost none on the inner edge.


glassesforeveryone 16 Jul 2007, 16:25

Hi Lydia,

I don't think there is a straightforward answer to your question about power rings.

I would imagine that the lense material has a big impact, glass, polycarbonate etc. Also, lenses can be bought with more refractive strength than standard.

I am no expert, but I think it's a tough question. My lenses are only -2.00 but power rings are quite evident.

Visitor 16 Jul 2007, 11:35

Thanks Roy, for your informative response.

Roy 13 Jul 2007, 01:47


I wear base out prisms with myopia correction. I have quite a difference in the myopia correction in my two eyes. Right eye is -4.00sph, cyl -1 at 90 degrees and left eye is -6.50, cyl -0.75 at 90 degrees. I have found that if the base out prism in the right eye is 4 prism dioptres higher than the left eye the outer edge thickness is about the same on both lenses. This would imply that 4 base out prism dioptres has about the same effect on edge thickness as 2.5 dioptres of myopia correction. With the fairly large aviator style frames I like, and CR39 lenses, I would estimate that each dioptre of spherical correction increases the edge thickness by around 0.8mm and each base out prism dioptre by about 0.5mm. You need to look up Prentice formula for the connection between offset, spherical correction and prism strength.

Visitor 12 Jul 2007, 23:22

Thanks saltnshake. Is there a way of working out the edge thickness for different amounts of prism?

Does anyone know how much 1 dipotre prism offsets the lens from zero prism?

saltnshake 10 Jul 2007, 15:09


Visitor 10 Jul 2007, 14:54

Hello everyone.

A quick question. I need a -0.75 correction in both eyes. How much base out prism would make the outside edge of the lenses as thick as a -4 without prism?


Clare 09 Jul 2007, 14:24

Plus and Minus - sure, I'm -3 and -2.75 with a tiny -0.25 cyl.

Plus and Minus 09 Jul 2007, 13:13


Would you mind giving your refraction or prescription numbers?

Clare 09 Jul 2007, 10:49

Plus and Minus - I wear aspheric contacts and I wondered what they were too till I did some research. I wear silicon hydrogel lenses and it appears that most of them are aspheric in design. The benefits, I understand, are that they are more precise than spherical contacts in directing the image onto the retina. It is sometimes necessary because of that to reduce the prescription, obviously because they can be too effective maybe! First thing I noticed when I switched was how crystal clear everything looked, I'm a great fan.

Plus and Minus 09 Jul 2007, 10:06

What are ashperic contact lenses - that are not bifocals - used for?

How do they work?

I understand aspheric lenses for glasses a little bit because I have had them but don't know why they would be used in contacts.

russell 21 Jun 2007, 06:01

I have worn progressives almost exclusively since I was prescribed bifocals over twenty years ago. I have never had a problem adjusting to them for any activity. Also, the last five pairs of glasses I've had were fitted with Varilux Ellipse lenses, which are the progressive lenses specially designed for small frames. Obviously, they work very well for me, or I wouldn't keep buying them.

Tanasbourne 20 Jun 2007, 19:45

On the Presbyopia Progression thread, numerous folks have assessed my wife's circumstances as soon needing bifocals to account for her impending presbyopia.

Because the frames she likes (and what looks good on her) are small, will that have an impact on her ability to adjust to either bifocals or progressives?

What is the normal 1st add to a 38 yr. old person's Rx?

What kind of difficulty do most people have in learning to drive with the bifocals or progressives?

Finally, what are people's preference in terms of getting bifocals v. progressives?

I ask these questions, because if the ES folks are correct and this becomes a reality, it will be helpful to have some education on this. She will not be all that 'excited' about it so the ability to avoid some difficulties would be nice.

Julian 28 Apr 2007, 06:36

( and oh, those typos!)

Julian 28 Apr 2007, 06:35

Roy: when I first got progressives I think big lenses were more fashionable than they are these days, and that helped - but also the precription was written with so much add for bifocals and an extra +0.5 for progressives. This meant not only that the lenses were good for a bit longer, but also that I fidn't have to look right to the bottom of the lens to get the reaing add I needed. As other people have said, and I've mentioned myself, optometrist these days seem to be kind of stingly with add.

Roy 28 Apr 2007, 01:38


I would agree with DWV that lens height may be a problem. I am -4 with a -1 cyl in my right eye and -6.5 with a -0.5 cyl in my left eye and I also have a prism of 10 base out right eye and 7 base out left eye. My add is 2.75. I tried varifocals with a lens height of 27mm but could not get used to them. Then, at my opticians suggestion, I went to the other extreme and chose aviator frames with a 45mm lens height. These are amazing. I don't notice any varifocal distortion and vision is good at all distances. I feel like I have regained the vision of a 20 year old and am not conscious that I am wearing varifocals most of the time. I think this is all down to a more gradual transition from distance to near which is possible with the extra lens height. I do have single vision distance and reading glasses but never wear them now.

John S 25 Apr 2007, 14:25


You have got a rough rx. A good bit of minus and a lot of astigmatism. I have never used a high index lens, people have commented that the higher the index, the more distortion there is.

My rx is +1.00 add +3.25. I don't have any problem using my progressive lenses. I am sitting in my work truck about 25 inches from my laptop using the intermediate zone.

I have found, the alignment of the lenses in most of the problem. You need enough height for the reading area, the lenses need to be centered correctly.

I had to shop around to find a doctor that would give me what I wanted. I am 51 now, I needed a strong reading add in my early 30s. The doc actually asks me before the exam, what the rx needs to be, then agrees. It is nice to be able to know, when you pick up your glasses, there are no surprises.

Rolly 25 Apr 2007, 10:05

Thanks DWV and Cactus

The lens height is 26mm I did not want to go any bigger on my face. Distortion does not seem to be a problem at this point neither is add area at the bottom of the lens. The issue is reading especially in low light conditions. I find the energy efficient florescent bulb especially poor at illuminating an area. Progressives do a poor job of incorporating add power. A +2.0 seems more like a +1.5.

DWV 24 Apr 2007, 21:07


It's slightly possible that the lenses are too small vertically, and there isn't quite enough space at the bottom for the reading portion, so you aren't getting the full add.

As for why docs are grudging with adds... it could be because higher adds mean more distortion with progressives, which leads to more dissatisfaction and remakes. Also stronger adds make the ground blurrier, so that walking and stairs are more dangerous. Maybe they're afraid of lawsuits.

Try different eye doctors; the last doc I saw just held +0.5 over my old glasses, asked if that was better, and increased my add by that much.

Lydia 24 Apr 2007, 21:05

At what point/prescription does one start to observe the "rings" in lenses? or maybe rather at what point are they significantly seen?

Cactus Jack 24 Apr 2007, 18:44


I don't have much experience with progressives because I tried them several years ago and because of the add (I think it was either +2.50 or +2.75) the transition zone was very small, distorted, and essentially useless. It could be that the the controlling factor is trying to stay with progressives. If you need +2.75 htere isn's much accommodation available for reading anyway.


Rolly 24 Apr 2007, 18:12

I picked up my new glasses a week ago the frames are nice, semi-rimless with the twin temples. Even with the 1.74 index progressives, the lenses are 5mm thick my Rx is -8.00, -3.00, +2.00 in both eyes.

I could not see properly both near far with my old glasses. I chose a new optometrist she agreed to work with me to resolve my vision problems. Now after wearing the new glasses for a week I still have trouble seeing close up especially in low light conditions. The doctor did not want to give me any more add. She believed I would loose my ability to accommodate. I told her flat out that I had a trial lens set and did an over refraction, I could easily take another + 0.75. The doctor took me to the optician out front and suggested we look at a different lens type that could help me with my reading. In the end it was determined that I already had the best lenses in the store and I should be persistent and give the glasses one more chance.

Why are doctors so afraid to give you more power even if you need it? What do you do when you visit five doctors in five years and your Rx is still out to lunch? Is it wise to test your own eyes?

Jennifer 27 Mar 2007, 09:26

Like seem to know what you are talking about. I just got my glasses back after being redone for the 4th time. They are perfect now. It took me filing a customer complaint to get them to correct my glasses. I received a letter acknowledging my complaint and they are supposed to get back to me on what has been happening. Your description of the cracking is correct. Obviously someone is very careless. I hope to prevent others from going through this. After all, we need our glasses to see and I wasn't going to accept anything that wasn't perfect.

LikeGlass 23 Mar 2007, 12:17

Some of the AR coatings can crack or craze when the lens is bent, which can be done as it is snapped into the frame. As crazy as it sounds, most new lenses can be just about bent in two without cracking, but the coatings, esp the AR coating can craze, forming hundreds if not thousands of little lines in the front surface of the lens. They may have someone working there who is a little brutal, and has learned that it's easier to pop lenses in that way, rather than the proper way.

RL 23 Mar 2007, 10:22


I have heard that the problem you describe is with the lens coating. It can react to the heat used in adjusting the frames. Not sure as to the soultion.

Puffin 23 Mar 2007, 08:03

If that was me it would the last time I'd ever go to them.

Some suppliers are okay with a deposit and you pay the balance when they supply the glasses, you can check them before handing over the balance. At least that way if they screw up you're not so badly out of pocket.

AA 23 Mar 2007, 07:02

Jennifer, sorry to hear of your problems with the company suppying your glasses. I would demand a refund of your money, and go to a company reommended by other satisfied customers.

I would sem to me there is a problem with the grinding of your lenses, more like faulty tooks which do the grinding.

IN this Day and age with high technical equipment your lenses should be perfect.

I think you have been far too patient, you have a right to demand your money bak and take your custom elsewhere where it will be appreciated.

I hope the problem is resolved soon, seems you can,t be without your glasses, as you say you have a high RX.

Good luck Jennifer all well that ends well.

daffy 21 Mar 2007, 17:44

Jennifer - could it be that the RX is wrong/not strong enough? Or maybe there is a batch problem from their supplier

Emily 20 Mar 2007, 13:36

Jennifer -- I have high index lenses and never had a problem like the one you're describing. Do you know what index they are? I used 1.60, but switched to 1.67 because my prescription got stronger.

Jennifer 20 Mar 2007, 10:17

I had an increase in my prescription and picked new frames. 1 week after my purchase I picked up my new glasses. After the fitting, I walked outside in the sunlight and knew there was something wrong with the lenses. I tried wiping them clean, but that wasn't the issue. They appeared to be scratched or even shattered. I walked back and complained. The optical tech. said the damage had been done when they heated the frames to bend them. He told me the lenses would be redone. Several days later I went back to get them and it was the same thing. I returned them, but this time the person helping me couldn't see the defect on the lenses, but he offered to do them again. A week later I went to pick them up for the 3rd time and was shocked to find the same thing. I'm very disappointed with this. After filing a complaint with the company they are offering to redo the lenses in another material. Because of my heavy prescription, my glasses are in made in hi index. I was told that for the frame I ordered, they will have to be made in another material to avoid the damage. The lenses will be light, but not hi index. I'm not convinced the heating process is damaging the lenses. Could it be the machine that grinds the lenses? Does anyone know of such a thing? Has anyone encountered something similiar?

Melyssa 19 Mar 2007, 04:24

On two occasions, for glasses that I wanted updated in my newer prescription, the frame broke. At least I was able to get the drop-temples in another color two years later.

For every pair of drugstore sunglasses (1960s-style cat's-eyes mostly) that I've wanted clear prescription lenses put in, there has never been a problem.

daffy 18 Mar 2007, 17:34

Puffin - and some of us have both the lenses and the frame...just not the tools to get the leneses into the frame.

They don't have a problem with it at all. All they say is that they cannot be responsible if the lens cracks or the frame breaks. Never happed to me.

Cactus Jack 18 Mar 2007, 15:20



I hope you read my post on the Post your Prescription thread. After you get an Rx that seems more reasonable, and if you want to try ordering glasses on-line I'll be happy to help, if you need it. Be sure and get your PD (Pupilary Distance).

BTW, the examiner has to give you your Rx and you do not have to buy glasses from him/her.


Puffin 18 Mar 2007, 14:04

Someone I know had it done the other way around, ie he had the lenses but no frame.

Wurm 18 Mar 2007, 09:57


Yes, most opticians can put lenses into a frame you bring in. Usually they will tell you that they can't guarantee the frame from breakage. But I've had it done several times and never had a frame broken.

rings 18 Mar 2007, 08:52

if I have frames without lenses, can an optician make the lenses for this frames? the model of glasses is about 4 years old. let me know!

DNBursky 16 Mar 2007, 23:55


I went to the eye doctor, opthamologist, a few weeks ago. When I left

I didn't look at the prescription. Now that I see it, I'm concerned.

In June, 2004 I was OD Sphere -3. Cylinder -1.75 Axis 87

OS Sphere -4.5 Cylinder -1, Axis 90

In February, 2007 I was OD Sphere -2.25 Cylinder -1.75 Axis 90

OS Sphere -4.5 Cylinder -.75 and Axis 90

I am curious, does this make sense that my prescription got weaker in

one eye and that my eye got stronger, I am concerned/suspicious? I

discussed this with the woman who supposedly checked my eyes at the

office,not the doctor earlier this morning. She said it's normal. How

can my eye get better in glasses to from a -3 to a -2.75 when in

contacts I wear a -4.5 in that eye. (I assume OD is right eye)?

Also, I was discussing lenses with two optical stores.

In one, he recommended a lense of 1.67 which cost $250, these were

for rimless frames.

In the other, he said polycarbonate is fine, which he didn't give a

width, I assume, of, and said I can get away with the lenses that

cost $159-189 as opposed to the $229-269 for their 1.67's.

With my presciption what do you recommend? Hope someone can help. Are

polycarbs that thin? Is the price for the 1.67 that different?


Hansel 06 Mar 2007, 15:34


I too encountered some problems with the new laws, flying from Manchester, even though it was a bottle that was still factory sealed. However I dispensed with hand luggage, and checked that in as well.

On my return, the staff at Geneva airport noted that the bottle was contact lens fluids, so it was medicine and therefore acceptable to carry.

Given the new regulations, do you think the manufacturers might get round to producing 100ml, rather than the 120ml bottles that they are currently?

Clare 06 Mar 2007, 13:54

Tom/Diva - I think it depends on they type of contacts. I was a victim of the new anti-terrorism security measures yesterday - I haven't travelled with just hand luggage since they introduced the new practice - and they took away a bottle of contact lens solution. That meant I didn't have enough for an overnight stay but fortunately I had some disposables with me. I say 'fortunately' but I don't mean it - they were the most hideous uncomfortable things! Now I remember why I gave them up.

So today I've been wearing my silicon hydrogel contact lenses all day and they are wonderful. I think lens choice is an important factor in the health of our eyes, although I have a friend who can wear her disposables for some 15 hours a day.

Tom 05 Mar 2007, 03:18

Diva: I'm really afraid I cannot help you more... but after the troubles you mentioned weeks ago with contacts, don't you think it should be time to move back to glasses (or blurr) for a while? I remember a friend of mine that was told to stop wearing contacts that often (basically 16 hours per day each day!) sice they were compressing her eyes too much, resembling the symptoms of a known pathology (which was not the case, fortunately).

diva 27 Feb 2007, 02:28

Oh and

a) I've lived overseas - not just NZ, so not same eye doc - even within NZ, I've been in different cities

b) My close up has always been pretty much fine.

Any advice is appreciated!

diva 27 Feb 2007, 02:25

Vision history:

a) got glasses when i went to college at 13. Probably -1.5 or so - to see blackboard.

b) had another test or two, had somewhere round a minus 2.5 / 3 over the years

c) Got first contacts at 20. I have no idea of the prescription - well I know they were -3ish, but I don't know if they were corrected for astigmatism, although I know my glasses always had it.

d) Contacts prescription didn't change much, although I sort of recall some increase at some point but I sort of recall that was because they didn't think astig was necessary. Or something. Maybe at 23 or so. Same at 25 or so.

I guess I should have paid more attention to the numbers.

This time I know it's gone down in minus and astig has been added. Still on trial lenses so I don't have a proper prescription card. Vision is better but maybe not quite what I would have expected (my eyes aren't THAT bad so I sort of thought the correction would have been better. I think she said -2.5ish and something astig.

Not really sure what to do / say?

Tom 23 Feb 2007, 06:23

Diva: Such a change in prescription sounds strange to me, too. With overcorrection of about -1 in one axis (that with astigmatism) you should have experienced a lot of troubles, especially in close vision, I suppose. Did you experience things like headache, blurr etc? Moreover, your near vision, say below half a meter, should have been much better without contacts/glasses at all. Did you found that doing close works or read was easier without that too strong correction? Finally, if that was not the case, don't you have other elements not to trust to your old eyedoctor? Such a wrong prescription appears to me as a really stupid mistake... Or is it possible that your vision has evlolved this way? I think this could be possible only if your are not older than teens.

By the way, it seems that some people here around knows yor old story, but I haven't been able to find the old posts someone is referring too. Which is your vision history?

diva 15 Feb 2007, 05:23

I think I posted this to the wrong thread earlier... sorry ...

So I've had an eye exam - it confused me.

From -3.5 contacts, I've been prescribed -2.5 but with a degree of astigmatism correction. Apparently my previous prescription was bumped up by minus diopter stuff instead of taking into account the astig.

I've been told it is half and half contacts and glasses wear.

I am still skeptical about the change in prescription. I just expected to go up half a diopter, not down and added to in other ways.

Should I get another eye check or believe this - I would love some advice before I order my glasses.

Thank you :)

lazysiow 13 Feb 2007, 22:00

definitely yes if it doesn't cost much.

Some people don't notice the difference but at night with lots of lights shining at your lenses you'll be thankful

jason 13 Feb 2007, 17:53

Is it worthwhile to get AR coating for glass lenses, or are they naturally more transparent than their plastic equivalents?

Random_eye 18 Jan 2007, 04:24

Thank you so much!

Brille 18 Jan 2007, 00:45

Random Eye:

The lens thickness calcualtor has been very accurate for me.

Random_eye 17 Jan 2007, 15:28

Hey I saw someone post a link one time that told you how thick the lenses would be. You would enter the info in all.

Does anyone know what that link is right off hand?


diva 05 Jan 2007, 01:14

hmmmm ... been OK to be blurry while i have been on holiday. not so sure about next week when i go back to work ...

i should probably make an appointment ... :/

Clare 02 Jan 2007, 14:01

Tom - you're tougher than most but your determination is an inspiration nevertheless! I guess that would be quite difficult for anyone who'd got used to good vision, especially over a 10 year period.

Tom 02 Jan 2007, 08:07

Diva, If I understand correctly, you are complaining about the fact that you can hardly tolerate contacts any longer, but you haven't been using glasses for the past ten years, is that right?

If so, there is a third possibilty, that I strongly suggest you to try: discard any correction and live in a blur as far as you can! Obviously you need glasses to drive or see a far board/screen, but if your life is made e.g. of travelling with the tube or bus to your office (and way back) and doing computer work, you can probably manage it with -3.25 without correction I did it several times. I've done it several times (and a have a pretty much similar prescription to you) and it works great. Once I had to wait three days to have my glasses fixed and I preferred not to wear my prescription sunglasses (it was a cloudy winter and walk or work with sunglasses was really embarassing!): after a small initial disconfort, I managed perfectly! Why don't you give your eyes a chance?

4eyes 31 Dec 2006, 08:54

"I’ve been out for awhile and… well, I don’t know if this is the right place to post."

Maybe I'd post this in the wrong site place... I'll try it again.

Mike 31 Dec 2006, 08:46

As a reluctant wearer myself at one time, and a pusher to the extreme of contacts even when they hurt, there comes a time.

I made the decision to give my eyes a rest and wear glasses and after a few days forgot about it. Get a pair that suit you, wear them and that's it. I still waer contacts for some sport, but glasses are far more comfortable.

To answer your question, 25cm would equal -4, 30cm = -3.25 approx, so much as you are with -3.5 CLs.

Go for it!!

Clare 31 Dec 2006, 06:43

Diva - you really have got to bite the bullet before you do yourself some permanent damage. I can't believe you can tolerate contacts 7 days a week without let up.

Derek 30 Dec 2006, 03:57

Diva , i wish you would stop talking about it and take action. You have spend the best part of a year moaning about your eyes, and asking advice. Lots of good advice was given to you, but it seems you choose to ignore. Think it time to put up or shut up

diva 29 Dec 2006, 22:07

well i am still where i was when i started posting here. to refresh, -3.5 contacts with naughtiness factor of no test in over 3 years.

my ouchy contacts started being good for a few months so i didn't really worry, but now they have decided to be a pain in the *unmentionable*. so now again scared to go and have an exam, but finding that (on the suggestion of someone in the chat measured it) i can see about 25-30cm (i'm sorry i don't know that in inches) clearly without my contacts in.

i am gonna repeat my question that - what should i expect from an optometrist if i do force myself to go? in rx and in what i should wear (no glasses since i was 19 which is roughly ten years).


i know it sounds lame but still.

4eyes 29 Dec 2006, 12:54

Hi you all.

I’ve been out for awhile and… well, I don’t know if this is the right place to post.

As I am on vacancies and holidays arrives together with summer arrives, my daddy began to be concerned and worried about me glasses. And not without a reason, he began to look for Opticians to provide me some spare glasses and to his and my surprise nobody were able to provide a glasses on my actual prescriptions so ended up, “again”, with two glasses, for they say they can not do a bifocal with add of +7, 75 difference plus 17º base out Prism.

Well… I don’t want to look or sound stupid, but I’ve got a pair of glasses by mid August with this same prescription and now I have to walk around with two glasses because nobody seems to be able to do new glasses with that prescription? The problem is that I really love to play my portable video game, so I have no choice but take out two glasses around has my daddy saves those I got from UCLA. How come?

Anybody out there wants to try to explain me that?

Thanks for any suggestion.

Filthy McNasty 20 Dec 2006, 11:53

Those are plano front (used for moderate to high minus).

Stingray 20 Dec 2006, 10:11

Puffin: What I have are glasses with flat planar lenses in the front and curved inward on the back of the lens. Any ideas?

Puffin 19 Dec 2006, 08:09

They curve inwards on the front and back. You can get more powerful lenses like this without increased thickness because a portion of the total strength goes on the front, and the rest on the back. The look a bit odd though.

Stingray 19 Dec 2006, 07:16

What are bi-concave lenss and what do they look like?

Moonshiner 16 Dec 2006, 13:30


Cactus is right. Optical 4 Less will make anything you want. Here is their examples page which has pics (among others) of a pair of -2.00 power with 12 mm lens thickness.

Cactus Jack 16 Dec 2006, 04:32


Check out Optical 4 Less. Their special order will make just about anything you want.


littleminus 16 Dec 2006, 00:06

This might be a strange request but can anyone explain how I can get the optical lab to make my new lens with thiscker edges? My prescription is a meagre -3 in both eyes, ideally I would like to have about say 5mm thickness at the edge. The diagonal distance accross the les in the frame I'm using is 48mm. Is this possible and what do I ask for?


-5.00 who luvs gwgs 29 Nov 2006, 15:02

Surely the coke bottle effect shows when you look at a lens at an angle -4.00 and above will show plenty of power rings my lenses and my gfs lenses (-6.50 and -5.00)show quite a few rings.I did see a girl recently wearing what appeared to be standard lenses about -5 or 6 showing plenty of rings they were not high index

Bethanne 29 Nov 2006, 10:31


I have to agree with Emily, coke bottles begin about -8 to -9.

I have real coke bottles with -14.5 & -16.5, flat fronts plus significant astigmatism in a horizontal angle plus 8d base out prisms.

Adam 28 Nov 2006, 12:08


I reckon that coke bottles begin to look noticable at around -4 or -5. mine began like that when i was 14 and steadily increased - I'm now around -9.

of course the added effect is when the front of the lens is made flatter ad bounces lots of light around - my gf thinks its really cool.

Emily 27 Nov 2006, 10:46

Hi Philosofer,

I think lenses start to really look like Coke bottles when the front surfaces go flat. That happened to me at -9, around 3 years ago. Since then, I've increased to -12 but they don't look much different in appearance, just a couple of mm thicker. Going from -8 with curved fronts to -9 with flat frontrs made a big difference in appearance.

spexfan 25 Nov 2006, 07:26

I start to really notice it at about -4, particularly in those larger chunky plastic frames which folk are wearing these days. I think it depends a bit if there is cylinder and which axis it is on.

Philosifer 24 Nov 2006, 18:26

Would any of you like to pass on your perceptions of where the 'coke bottle' effect (aka a serious number of power rings) really becomes very noticeable ?

I know a couple of people with -5 and -6, and it seems to be just beginning to show there, and a couple with -12 and -14, where there seems to be no doubt about it ?

Also , though high index lenses may be physically thinner, their optical effect is meant to be about the same ?

So has anybody observed carefully when power rings first become really visible, in high index as well as regular lenses ?

daffy 12 Nov 2006, 15:02

leelee - for plus lenses, it is also important for the lab/techs to use a smaller diameter semi finished lens. This in turn reduces the edge thickness.

leelee 10 Nov 2006, 07:08

Would the size of the originating blank material also affect the thickness of your lens?

My new pair of +3 sv reading glasses have a very small lens (30--26) and the edges are still about 3.5 mm (not that much, I know! but it does stick out of the frame in the back) and obviously a bit thicker in the center.

These were very inexpensive glasses and I don't care about the thickness (I chose the frames for their funkiness) but do they sometimes use smaller blanks in order to get the lens thinner? I mean, its all about the curve, right?

Cactus Jack 10 Nov 2006, 06:28


You are right, I wrote down 1.56 without checking my facts. Shame on me. I have seen several numbers but they are all around 1.498 - 1.501. I looked up CR-39 in Google and found this interesting, fairly readable, link about CR-39:

I note they list the index of CR-39 as 1.501 at 20 degrees C.

Puffin & Bill,

CR-39 is a polymer which is a "plastic". Mostly people refer to "plastic" lenses to differentiate from glass. The newer high index materials are also "plastic".

The link offers a very detailed explanation of CR-39's characteristics and advantages vs 3 other materials. It is "low index" by todays standards, but it has a lot of redeeming features that keep it in common usage - it just isn't "thin".


Puffin 10 Nov 2006, 03:18

Yes I've heard of this low index referred to as "plastic" for some reason.

Highmyope 09 Nov 2006, 19:16

And Cactus--unless the numbers have changed in the last 10 years (and they might have) CR-39 has an even lower than that--something like 1.498. 1.56 was the lowest of the various levels of high index--at least back in my day. :)

Highmyope 09 Nov 2006, 19:12


They are lens blanks that need to be ground. A 6 base curve is for low powers (roughly -2 to +2). A 5 base is for the adjacent minus range, say -2 to -4.

Yes, I used to be a lab tech at an optical chain. :)

Cactus Jack 08 Nov 2006, 19:20


CR-39 is a plastic lens material with a relatively low index of refraction, about 1.56. It is considered a very good general purpose lens material and it is low cost compared to some of the high index materials available today.

Because of its low indes, lenses will be thicker with CR-39 than high index materials.

Other than low index, it has superior optical properties compared to some of the high index materials.


Bill 08 Nov 2006, 19:00

Cactus Jack

What is a CR39 Lens?



daffy 19 Oct 2006, 22:51

Thanks for that info. I think i may need to send an email to manufacturer and find out that way.

I always wondered about progressive lenses and how they are supplied especially when a cylinder correction is required. For every 1 degree axis, there would need to be 180 variations for every spherical power. Don't think that is practical. I guess that they grind the spherical and cylindrical onto the semi-finished lens. I guess now i know why progressive lenses cost a lot - each is basically tailor made.

specs4ever 19 Oct 2006, 20:25

Ok, I sort of understand. But if the front is a +5 base that won't give you much of a minus. On a plano front base, if you draw a 6" diameter circle, this will give you -5D. But, if the front base is also 5D then you will in effect have a zero powered lens. However, if you do not use all of the diameter of the lens, and draw a 4" diameter circle, this will give you a -10D, minus the +5 base, and you will get a -5D lens. (and a 3" diameter circle will give you -15D, a 2" will give you -20D and so on.) These are just rudimentary calculations though.

daffy 19 Oct 2006, 18:18

opps...that didn't work too well after submission...sorry

daffy 19 Oct 2006, 18:17

The front is dome shaped and the inside is dished in. Basically like this;

/ /

/ /

- -

\ \

\ \

I tried to find out what the maximum minus Rx it can be ground to, but not getting far.

specs4ever 19 Oct 2006, 16:27

You are correct in your thinking Daffy. Is the one side dished in, or is it dished out. If it is dished in then the base is 5, and if it is dished out the base would likely be a +5 - providing the other surface is plano

daffy 19 Oct 2006, 16:22

I have a technical question I hope someone can answer.

I recently acquired lenses. They are progressive lenses. The marking on the box/package says BASE 5, ADD 2. Just looking through the lenses they are plano with a reading segment. The lenses are 80mm diameter. They are also anout 10mm thick at the edge. Index = 1.537.

From my limited knowledge, I have come to this conclusion…The lenses are a ‘blank’ and need to be ground to an Rx. Is this correct? How do I know what the maximum minus Rx these particular lenses can be ground to? I presume the “BASE 5” marking is the curvature of either the front or back of the lenses. I also presume (since it doesn’t say “+” 2 Add, just “Add 2”) that the add is a plus 2.

Any ideas? Or is this too technical for this forum?

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ipml 13 Sep 2006, 09:21


Thanks for the info on your new myodiscs. Any chance of getting a picture of them?

Raznoe 13 Sep 2006, 03:55

Nice layout. But i didnt find information for me that i try to find on your website. But thanks you in any way! Hi! Guys how you manage to make such perfect sites? Good fellows! Good site! It is very creative and includes a wealth of information. Hello nice page and it downloads very fast, enjoyed it very much, take care. Cool design, great info!

Raznoe 11 Sep 2006, 17:32

Ill be back very soon to see any update!!! This is one of the best sites I have ever found. Thanks!!! Very nice and informal. I enjoy being here. You are the best! Im glad... You are the best! Im glad... Sehr guten site. Alles arbeitet deutlich(klar), schon eben storungsfrei. Wer machte? Vielleicht vom Weg?

Danny 08 Sep 2006, 09:19


They are great! they are lightweight and i paid for titanium frames that had small dimensions and a wide nose-gap. The vision is fine, its only when Im reversing my car into a parking space i notice the edge of the lens. They have a magnifying edge to the outside of the myodisk part.

Cactus Jack 08 Sep 2006, 07:18


Normally, the intermediate segment is 1/2 the power of the reading segment so at low add powers, trifocals wouldn't be worth the cost, would not be prescribed, and as DWV said, would not be made.


DWV 08 Sep 2006, 00:51

The lens catalogs I've checked out generally show the lowest available add is 1.50

Wayne_D 07 Sep 2006, 20:25

Cactus Jack,

Do you know if trifocals lenses are available in less than +2.00 add?

Catalog 07 Sep 2006, 09:34

Super site ! Bravo au webmaster qui a su rendre le site tres interressant.Continue comme ca ;) This web-site is the coolest! Now I dont have to feel so intimated by science! Youre a genius! I think Ill visit this site often. Perfect site! Anything superfluous, all is laconic and beautiful. Thanks! Hi! Guys how you manage to make such perfect sites? Good fellows! Hi! Guys how you manage to make such perfect sites? Good fellows!

ipml 06 Sep 2006, 11:20


I am thinking of getting myodiscs myself, although my Rx is lower than yours (-16 in my worst eye). I would like to discuss myodiscs with you, how you like them, etc. My email is Hope you write to me.

Raznoe 05 Sep 2006, 16:18

Good site! It is very creative and includes a wealth of information. Ill be back very soon to see any update!!! You have many friends that post in your guestbook - it is cool! I glad too see this interest site, I tell my friends about it! They like sites like that: site Super site ! Bravo au webmaster qui a su rendre le site tres interressant.Continue comme ca ;)

Karl 10 Aug 2006, 13:25


I assume from some of the things you mention in your post that you are from the U.K. I would like to chat more about your myodiscs, if you would like to do the same then please email me at

Danny 10 Aug 2006, 00:15

I'm 35

Cactus Jack 09 Aug 2006, 19:47


I have seen Rx written to 1/8 D and I have seen trial lens sets with +/- 0.125 and +/- 0.375 lenses. I suspect that they are prescribed very rarely.


Puffin 09 Aug 2006, 18:46

Does anyone know if you can get lenses for fractions of a diopter less than 1/4? ie 1/8th, 1/16, etc?

Karl 09 Aug 2006, 16:45


Luck you having your glasses made up as myodiscs, somrthing that you see very rarely in the U.K. Can I ask how old you are?

Danny 09 Aug 2006, 10:16

I posted here a few weeks ago about my new prescription: (R-19.00 -1.50 090 8bo and L-17.50 -1.25 060 8bo with +3add)

Finally got around to collecting them today - 2 problems the man in the shop said 1st: Varifocal hi-index lenses they couldn't get so they wanted me to have another eye test (so I blew my top and asked why did I pay £17 for an eye test last month if they didnt trust it)

But the second problem was amazing: the free pair contained "lenticular lenses" which everyone here calls myodiscs. So I maintained a matter-of-fact expression, but I'm secretly delighted!

I will post some photos later this week when Im back at home near a camera!

Will 08 Aug 2006, 09:24

Hi Neville,

I just followed link posted - you dont appear to have to join to read through the posts, certainly thats all I did.

The link to the section on progressive lenses is as follows



Neville 07 Aug 2006, 22:06


How did you get into the optiboard site? It tells me you have to be eligible to join.

Will 07 Aug 2006, 14:32

Sorry DWV!

Will 07 Aug 2006, 14:27

Hi Wayne & DVM

Thanks for the tips. I've had a good read through the optiboard site. What seems to be realy interesting is the comments that if you want the best possible quality of vision don't use progressives as they are ultimately a compromise.

Before I decided to try out the progressives I was using trifocals, and a number of people I've spoken to have said that they just register that I'm wearing glasses rather than what the lenses are like. This being the case I think Im going to go back to trifocals rather than put up with the narrow field of view and distortion that the progressives give.

Untill I had spoken to people about it I hadn't really thought about how other people viewed the glasses I am wearing, I just automatically assumed that the trifocals stuck out like a sore thumb. ( I could still of course be kidding myself here)

So here's to function preceeding form, I'll revert back to the good old trifocals. The other thing I should mention is that I decided against high index lenses some time ago as they seem to produce more chromatic aberations than standard lenses. This may again be becasue of the prism in my prescription, but with a standard index lens I find the aberations more reduced. With the lower index lenses they are just under a centimeter thick at the outside edge, definately function preceeding the perceved form!


DWV 04 Aug 2006, 00:09


It should help to read some of the discussions of progressives at

That's a forum for optical professionals (opticians, eye docs, lab techs), so civilians aren't encouraged to actively participate. But, there's been a lot of discussions of the pros and cons of different progressive lenses there, so you may find some pointers to a model which will work better for you.

And, visit a bunch of different opticians and ask for advice. Opticians with grey hair should be more credible than youngsters, since they'll have first-hand experience and not just repeat whatever the last sales rep told them.

Wayne 03 Aug 2006, 17:29

Oops. I forgot to mention the add for near vision in my Rx, +2.50 both eyes.

Wayne 03 Aug 2006, 17:26

Will -

There are a number brands and varieties of progressive lenses. I just got a new pair that is working quite well for me -- unfortunately, I don't remember which it is. I recommend finding a skilled optician to make the glasses. He/she can discuss with you the different types based on your visual needs.

Progressives do work much better if the lens is deeper top to bottom. My previous pair were in a smaller frame that didn't give me enough area for comfortable reading.

My Rx is L-5 R-4, no cylinder or prism. I suspect prism especially would create more complications. Again, a good optician is suggested since their training is fitting glasses.

Will 03 Aug 2006, 08:08

I recently got some progressive lenses on a trial. Cosmetically they are great and the infinite focal range is very useful. However, the field of view with them is very limited.

I have had some success adapting to the progressives, but the narrow viewing angle is a problem with so many activities.

Does anyone know which brand of progressive offers the widest viewing angle?

My prescription does have prism in it, I dont know if that would have any effect?

L+1.50 -2.00 6 Base Out

R+1.50 -2.00 6 Base Out

Great website guys.


Peter 02 Aug 2006, 18:50

Wayne_D -- If your friend's glasses are -8, the contacts should probably be between -7 and -7.5. It depends on her vertex distance.

If she likes glasses, then wearing them is great. But if she'd prefer to wear contacts, she really shouldn't stop just because she thinks her contacts are too weak (or too strong); she should get new contacts at the right prescription.

If she's having headaches with contacts, though, it could be an issue of having astigmatism that's not corrected by the contacts. If that's the case, toric (soft) or rigid (RGP) lenses could help.

Catalog 02 Aug 2006, 13:29

Don’t walk behind me, I may not lead. Don’t walk in front of me, I may not follow. Just walk beside me and be my friend.

Wei 12 Jul 2006, 12:07

Can 1.9 lens be made in to bifocal? I think two lenses can be join to make bifocal??

Cactus Jack 02 Jun 2006, 08:46


There are several formulas. A fairly common one is as follows:

Refracted Rx power squared divided by 1000 then multiplied by the vertex distance to arrive at the CL power.

In this instance, you are wnating to work backward from the CL power which will give you slightly less than what would have been refracted because you are squaring a smaller number.

For example: if the refracted Rx was -9.00, 9 squared is 81, divided by 1000 equals 0,081 times 13 mm = 1.05. Therefore the CL Rx would be -8.00. If you work from the CL Rx you will get 0.83 so you might arrive at -8.75 for the glasses.

If she wants to go back to glasses, the best thing would be a refraction so any cylinder correction could be included.


DWV 02 Jun 2006, 01:53

The lowest add that trifocals are made in is 1.50, but they generally aren't necessary or recommended until the add gets close to or above 2. That's because if you don't need a near add over 1.5 for reading, you should still have enough accomodation left for intermediate distances.

These days progressives must be outselling trifocals at least 10 to 1. Most days the only trifocals I spot anyone wearing are the ones on my face.

Wayne_D 01 Jun 2006, 22:20

Cactus Jack

More questions. Is there an add power starting point that trifocals are prescribed at - I've heard they aren't prescribed below +2, but I don't know. Is the criteria for prescribing them more a matter of what type of close work is being done or is it more a matter of flexibility of the eye's lenses.

On another topic. Is there a formula for calculating the difference in lens power between a minus power contact lens and the lens used in glasses when the correction is the higher ranges, given that you know the lens power and the vertex distance? I have a friend who decided to go back to wearing her glasses because her contacts were weaker than her glasses and she thought it was the source of headaches. She is in the - 8 area. I want to give her an idea of what her contacts should be based on her glasses prescription.

Johnny Van Wert 01 Jun 2006, 20:47

Lenses... so does anyone here have pics on strong astigmatism lenses?

And, about prescription of the lenses...

Actually what's the difference between these prescriptions? And how would the lenses look like? And which of them are "stronger" prescription (That means the eye has less acuity?)

-3.00 +3.00 60

-3.00 -3.00 60

+3.00 +3.00 60

+3.00 -3.00 60

I'm curious about this because my cousin was recently prescripted with a lenses with about +3.00 -3.00 60... don't really understand how would that glasses works. It just looks like distorting his vision...

(Let me tell you my prescription: I'm an nyperope, but I do not suffer from astigmatism. +3.00 for left eye and +4.50 for right eye. When doing close works, I have to use another pair with stronger plus lenses... +5.00 for left eye and +6.50 for right eye)

DWV 27 May 2006, 20:28

X-Cel Optical has trifocal lenses with 40, 50, 61 or 70% power in the intermediate segment, with adds up to a whopping 6. The intermediate segment can be had in heights up to 14 mm.

Cactus Jack 27 May 2006, 11:43


The 7 or 8 is the segment height of the intemediate segment in mm. The 28 or 35 is the segment width in mm.


Wayne_D 27 May 2006, 11:00

Cactus Jack

Thanks for your answer. Can you also tell me what the trifocal reference 7/28 or 8/35 means?

Cactus Jack 27 May 2006, 09:18


The +2.00 add is for the lower reading segment. The intermediate segment is normally one-half the add or in this instance, +1.00. However, there are blanks available with different power intermediate segments for special cases where one-half won't work.


Wayne_D 27 May 2006, 09:01

Cactus Jack

When trifocals are prescribed how are the lower two segments of the lens divided. For instance, if the add is +2.00 is it specified on the prescription what each segment is or is a formula or ratio used to divided the add into sections?

Patrick B 12 May 2006, 08:58


My lenticulars are biconcave and have a negative carrier which I think looks so much better from the front. They're also over ten diopters stronger than your prescription, and I haven't got a choice but to use this sort of lens. While lenticulars are available in the "lower" ranges like yours, I don't think they're all that common any longer what with all of the advances in high-index lens materials. Optical4Less doesn't sell lenticular lenses unless they are -20 or more. I think they used to have them as low as -15. I don't have 20/20, and I suspect that Peter's fully-correctible vision is less than 20/20 as well.

radioman 12 May 2006, 08:20

Peter -What is your vision level with the -40's. Is it 20/20 or in your country 6/6?

PETER 12 May 2006, 07:51



Puffin 11 May 2006, 17:56

I think the minus carrier looks better from the front, too. And if you happen to look through the carrier, things look a bit clearer (so I'm told) than through a plus carrier - but then, you could always look through the lens bit anyway.

RL 11 May 2006, 16:45

Wei, there seems to be no difference in vision. The plus carrier will result in thinner edges but I think the minus carrier looks better from the front. Where did you get the minus carrier lenses? I can find only plus these days.

Wei 11 May 2006, 11:53

RL Did you find better vision with minus carrier? Is there much cosmetic different between plus and minus?

squinty 11 May 2006, 09:37

I've had convergence insufficiency for a long time and have managed it totally with exercises. My research shows that prisms are not as useful for convergence insufficiency as Vision Therapy (the eyes tend to adapt to base in prism requiring endless increases) VT is shown to be quite successful for this, with prisms reccommended only as a last result.

It can be time consuming but its really worth it.

Matt: I agree with you the "pencil pushups" are pretty worthless (I recently saw a new study that confirms this.) The things that have worked with me have been:

working with prisms as exercises (fusion with for a 5 count and then without, working up to about a 12d prism)

using a brock string (little beads at different distances that you focus on up and down the string

+/- flippers

3d fusion exercises using something called a tranaglyph

contact a behavioral optometrist for real vision therapy.

LisaP 11 May 2006, 04:44

The eye doc tried prisms on me, but i think eye exercises are a better solution for convergence insufficiency. i've already tried some of the exs. and can feel my lazy eye struggling to focus... that's a good sign!

LisaP 11 May 2006, 04:43

May need a prism, but trying eye exercises for now. Let's see what happens. Apparently having problems converging. Must have had pseudomyopia past months.

Tim 10 May 2006, 17:07

Sorry, LisaP - I didn't see your 00.53 post until this a.m. due to time difference (it is 8 a.m. here now).

I do hope that all went well for you and you got what you want.

RL 10 May 2006, 16:29

Wei, It seems that most myodiscs these days are plus carrier. I would like to know where to get minus or plano carrier lenses. I had some plano carrier myodiscs in the 70's but they were glass. Now it seems all I can find are plus carrier. My Rx is -14.

Wei 10 May 2006, 13:31

Do anyone have experience of difference in minus or plus carrier for myodiscs? I have minus carrier but wonder if there is benefit for plus carier?

mattp 10 May 2006, 06:28


The doc had me do some vision training at the same time as I was using the fresnel prism. He had me hold my index finger at arm's length and slowly move it to the tip of my nose. I was to force my left eye to stay focused (that is, to not turn out)on my finger for as long as I could. I found it a pain to do so just told him I was doing it faithfully and it wasn't making any difference.


LisaP 10 May 2006, 05:20

That sounds like what I need, but I have problems focusing far and near.

Did you optho suggest vision training or prescribe prism straight away?

Mattp 10 May 2006, 05:14


For a couple of years now I have had prism correction in my left eye. I was having difficulty with close work because my left eye kept wanting to wander out, giving me difficulty focusing and headaches. The doc first tried a stick-on lens with all kinds of little lines called a fresnel prism to see how I would adapt to prism correction. No problems, so he prescribed a 2 diopter base in prism for my left lens.

The left lens is a bit thicker near my nose, but it is not particularly noticeable. The comfort level of wearing the prism is fantastic--I can feel my left eye pulling inwards to work with my right. Without my glasses or when wearing contacts (which have no prism correstion), I do fine except with close work. And it is more comfortable with the glasses.

Good luck--matt

LisaP 10 May 2006, 04:50

Another questiona bout prisms.

I don't have double vision, but just can't get my eyes to work together. Will the prism base-in really help my eyes to converge?

Cactus Jack 10 May 2006, 03:37

Oops, the post for Larika was from me.


 10 May 2006, 03:36

C 10 May 2006, 03:35


The drawing is not realistic. Its purpose is to illustrate that in a myopic eye, the rays of light focus in front of the retina which is corrected by a minus lens. In this illustration, the myopic eye is shown as spherical which it typically is not.

For the condition depicted in the illustration to exist, the cornea and the crystaline lens would have to have about twice the normal plus power to move the focus point to the center of the eye. The formula for calculating focal length of a lens (system) works about the same inside the eye as it does outside the eye.

For eductational purposes, I suggest that you perform the calculations based on a normal spherical eye diameter of 1 inch or 25 mm. What plus power would be requred to focus an image on the retina of a normal eye? What plus power would be required to focus the image at the center of the eye? What minus power lens would be required to neutralize the excess plus power if it had 0 vertex distance (a contact lens)? For extra credit, what would be the approximate power lens required to correct the excess plus power if the lens was 14 mm in front of the cornea?


Cactus Jack 10 May 2006, 02:50


Base In prism for an eye that turns outward.


Larika 10 May 2006, 00:56

What would be the approximate prescription for the below myopic eye diagram:

LisaP 10 May 2006, 00:53

thanks for post, tim. Do i need base in or base out for an eye that turns outwards?

going to see my orthoptist this afternoon... wish me luck!

Tim 09 May 2006, 21:18

Thanks, folks. But I should still have thought that it would be less confusing (and easier) to measure it in degrees!

Cactus Jack 09 May 2006, 20:47

I believe the technical name is Prism Diopter and the definition in Filthy's post is correct. If you do the math, you will get the angle whose tangent is 0.01 is about 0.53 angular degrees of deflection per prism diopter.


specs4ever 09 May 2006, 19:37

Are prism's not measured in degrees rather than diopters?

Filthy McNasty 09 May 2006, 18:40

From that, I suppose it ought to go without saying that prism diopters are different from standard refractive diopters. A lens' diopter is the reciprocal value of its focal length in meters.

Filthy McNasty 09 May 2006, 18:38

A one diopter prism will deflect a ray of light one cemtimeter at one meter. That's how.

Tim 09 May 2006, 18:18

Since prism correction does not alter focal length, but only direction, how can it be measured in dioptres?

And why is it that ECPs are apparently so reluctant to prescribe it?

Roy 09 May 2006, 12:06

Lisa, I am 58 and have had prism correction in my glasses since the age of around 15. I can still remember the way my eyes suddenly felt as if they were working perfectly together when the prism was prescribed. I have had the prism correction since then and have had no problems whatsoever. On a couple of occasions, when I changed opticians, they persuaded me to try leaving out the prisms but I always struggled to see with both eyes together and was back within days to get the prisms restored.

The prisms hardly affect the appearance of the lenses. They just make them thicker wherever the base is, and thinner on the opposite side.

I would say if you need the prisms go for them.

LisaP 09 May 2006, 08:29

Sounds awkward! I'll see first if I need the prism correction.

Phil 09 May 2006, 08:12

Lisa, lenses with a graduated correction. U said in one of your posts that you thought that you might need different correction for distance, on the one hand, and close work on the other. Do you think it might help if you had full minus correction in the top portion of the lense and something less at the bottom for reading etc.?

LisaP 09 May 2006, 07:13


What are progressives and why might I need them?

Lisa P 09 May 2006, 07:12

I've given up working today, as I can't focus at all, it's driving me crazy!

Doing some research for my appointment tomorrow and still not sure whether i need base in or base out. (It's my right eye that turns outwards)

Phil 09 May 2006, 07:08

LisaP, will progressives help? It might be worth exploring that too. I do wish you well. I want you to get a solution that helps you see and look good at the same time. I'm so sorry we got off on the wrong foot yesterday. Don't forget to let us know how you get on.

LisaP 09 May 2006, 07:04

I need base out prism according to this:

Base-Out (BO) Prism- a wedge-shaped lens which is thicker on one edge than the other. The thicker edge (base) is turned outward, closest to the ear. Prisms bend light (opposite direction from its thicker end) so the base-out prism turns the light inward (toward the nose) thus causing the eye to also move inward. This prism is used to measure an eye misalignment and/or treat a binocular dysfunction (eye teaming problem). Prisms are sometimes added to glasses to help improve eyesight due to a misalignment or visual field loss.

LisaP 09 May 2006, 06:43


My "new" rx is -1.75 (Right) and -2.00 (left) (before i was -2.50 and -2.75). These weaker lenses are giving me headaches and my right eye is going "dead". I can feel that my right eye needs help focusing, it needs to be directed to the left a little.

Have made an appointment with orthoptist for tomorrow. I want to try prism lenses, do I need base in our base out?

I wear my glasses full time, but think i should only wear correction for my astigmatism for near work. Will also ask about this tomorrow.

Hopefully prism will be the answer! Wish me luck!

Cactus Jack 09 May 2006, 06:36


Please forgive me, I understand your concern about appearance. Even at my age (68) I don't like wearing my high prism glasses (15 BO / 15 BO) in some situations where I think they might be distracting. I have some 7 BO / 7 BO glasses that I can get by with if I am not too tired. They have a slight tint 10% and it is almost impossible for others to tell that I am slightly cross-eyed because it cuts down on internal reflections (internal reflections are what cause "power rings" in higher minus lenses). Also, 7 diopter of prism only allows the eye to turn inward 4 degrees which is almost impossible for others to detect - particularly if both eyes are turned inward the same amount.

If you get prism lenses, I would suggest the following. If the prism is horizontal (Base In or Base Out) try to get half the prism correction in each eye. Prism in only one eye is much easier for others to spot. Ask for a very light tint as mentioned above. Anti-reflective coating may help. I haven't tried it.

What is your glasses Rx?


Phil 09 May 2006, 06:32

Lisa, from what I've read here in the past I don't think that a modest amount of prism affects the appearance of the lense very much or at all. So you shouldn't worry on that score. You have quite a modest minus rx anyway. Adding prism does seem to make one dependant on glasses but I think you probably wear full time anyway. I've often found opticians unwilling to give me enough close add: I think it's because I need a little more than the books say is "normal" for my age. I fear one just has to insist on what one wants.

Cactus Jack 09 May 2006, 06:10


I agree that Lisa needs the proper corrective lenses very much and I hope she can find an Eye Care Professional (ECP)that understands and will help her. I have been there and done that. It was my own vision problems that led me delve into the "mysteries" of vision and optics. Unfortunately, most ECPs are "trained" (programmed) to follow certain procedures and have no experience in solving uncommon vision problems. Fortunately, my technical background and knack for problem solving helped me and I finally found an ECP that would LISTEN and help when he discovered I could speak his language and probably understood my problem better than he did.

I did not intend to suggest that Lisa wear the eyepatch all the time. Only that she might try it and if it helped, use it in those situations where she was having trouble functioning, it was appropriate, and comfortable (in private).

Before I finally found an ECP who would prescribe enouth prism, I was having trouble with double vision if I had to read a lot and was the least bit fatigued. I found that I could close one eye and read easier. I decided to try an eyepatch and it worked even better. Also, the fact that I had resorted to an eyepatch helped convince the ECPs that I seriously needed prism.


LisaP 09 May 2006, 06:01

Well, my problem is starting to cause serious problems. I can't read things properly and skip lines, will try to see a new opthomalogist asap., one that understands my problem, or should I see the orthoptist again who referred me to another eye doctor, who told me to change my lenses?

Agree about the prescription, what I should and need are two different things, it seems.

Cactus Jack, a patch ? I'm in my late twenties! I'm even reluctant to try prism lenses, so I wouldn't be seen dead wearing a patch.

Phil 09 May 2006, 05:18

Come off it Cactus Jack. Haven't you read Lisa's posts? The poor girl said "Guys are never going to fall for me." Do you think dressing her up like Pongo the Pirate is going to do anything for her self-esteem? Lisa just needs the right lenses, including some prism if that's the answer. I find that opticians are too ready to substitute their preconceived ideas about the correction one "should" have for that which one actually needs. I would advise Lisa to find a new optician who is willing to listen. Medical practitioners so rarely understand the psychological effects of the treatments they prescribe or the advice they give. And opticians can be just as bad. Good luck Lisa.

Cactus Jack 09 May 2006, 04:35


While not very attractive, you might consider getting an eye patch to wear in a pinch. Sometimes, stable vision with one eye is better that unstable double vision.


Lisa 09 May 2006, 00:55

Well, it's only been a few days with these weaker lenses and my right eye (lazy one) is not working with the left. At least with the stronger lenses, I didn't have this problem (although I did cross eyes when reading, as prescription was too strong for close work).

The optician told me to wait two months before coming back for another appointment.

I'm using mostly my left eye to see at the moment, as the right looks elsewhere. Cannot stand another two months of this, so will see about getting a prism. and in the meawhile put back in my older lenses, and get a weaker prescription for computer work.

big ES fan 08 May 2006, 11:44


Astigmatism will sometimes make one of your eyes turn in or out, depending on the axis. My cylinder in both eyes is a little higher than you and it made my eyes turn out which made it difficult to read or use the computer for long periods. After my optometrist was being reluctant, I just told him that sometimes I see double and wanted prism. When he ckecked, with the two red dots test they were not together, so he added base in prism untill the dots were together. I ended up with 2 degrees in each eye. The difference is amazing. Sometimes they are reluctant to prescribe prism and you have to force the issue in order to get the right prescription for your eyes to relax.

Wei 08 May 2006, 11:16

Lisa. Perhaps prescribe of prism result in worsening of problems with eye muscle?? I hear optometrist not very keen to prescribe for dependance problem but if person wears glasses all time any way this not a serious problem so perhaps there is other reasons? I think if eye muscle may become more lazy with prism and problems worsen. But if you want prism try different optometrist. I have problem sometime of double vision if reading at night but am told do not need prism.

Oscar 08 May 2006, 09:51

Hi Lisa,

I'd like to hope that the optician will realise this – and it sounds as if you're having a bit of a nightmare with under-correction for distance at the moment as well. As you say, the whole vision training thing is time consuming and won't necessarily work – I did it from the age of about 3 until I was 15 with absolutely no success. I know it works for some people... but even so, I'd be inclined to give prism a go, especially as you are happy to do so. I suppose all you can do is wait for your next appointment, but speaking from my own experience, I'd say try it. Good luck.

Lisa 08 May 2006, 08:18

Hi Oscar,

Well, first the optician gives me a weaker prescription (did the eye test with those drops that dilate your pupils). She says that I'm stressed (and my eyes are too), and should try this new prescription (quite a difference from my older one, can't read much in the distance) and in two months' time come back and see if I need to do those vision exercises with the orthoptist.

I also did that visual field exercise and apparently all my answers were right, even though when doing my right eye, the light in the centre was much blurrier and thought I would fail. The optician never questioned me about how I felt during this exercise, but I could feel the muscles in my right eye being pulled and my eye having great difficulty focusing. Anyone else ever experience this?

I'd like to try the prism, as I don't really have time to do the whole eye training thing. I really don't care at this stage if I'll be stuck wearing prism lenses for the rest of my life, my eyes are already messed up as it is! Is there any way an optician will prescribe a prism instead of visual training?

oscar 08 May 2006, 08:01

Lisa, I've worn prisms for a lazy eye since I was a kid. I find them very helpful (essential actually), but the down side is that I found I very quickly became dependant on them. So it's possible your optician is giving you some good advice in suggesting you don't need them (and that you make your eyes work together). In my case, the muscles were all far too messed up for that to be an option.

This isn't a very helpful answer...sorry. As I say, I find them not only helpful but essential and it might well be a good idea to give prism a try.

Phil 08 May 2006, 07:20

Sorry Lisa, didn't mean to bother you!

Lisa 08 May 2006, 07:12


I just wanted some advice on this forum, that's all. If you can't help me with my problems, let me be.

Lisa 08 May 2006, 06:59

Does anyone or has anyone on this forum ever worn a prism for a lazy eye. Think I might need to wear one as right eye won't focus, but my optician insists that I don't need a prism.

Does it really correct lazy eye? What does it look like? I'm quite shy and self-conscious so don't want to draw too much attention...

Phil 08 May 2006, 06:55

Yes I do Lisa. I'm -3.75 in each eye. Only -0.5 astigmatism in the right and none in the left, though. I wear progressives, with a +1.75 add for reading. It would be good to chat in Lenschat but I can't get into the damned thing! I'm on 07783062869 if you want to text!

Lisa 08 May 2006, 06:50

Left eye and right eye are quite different Rx.

Left -2.50, astigm . -1.75

Right - 2.00, astigm. -1.25

Well, I should know enough about lenses, been wearing glasses long enough.

And you, do you wear glasses?

Phil 08 May 2006, 06:17

Sorry Lisa, "2.75" should have ben "2.50"!

Phil 08 May 2006, 06:16

Lisa. How wrong you are. Most guys find a girl who wears glasses a much more attractive prospect than one who doesn't. They really do. U seem to know a lot about lenses. What is your exact rx? When you say that you are -2.75 do you mean sphere or cylinder or some of each? How long have you been wearing glasses? Do you wear them full-time?

lisa 08 May 2006, 06:10

Yes, I am a little worried. In my late twenties. Hate wearing glasses so much but squint badly if I don't wear them, because of astigmatism. My optician says I don't have a squint, did that field vision test, but I feel I do... When I look in the mirror, I see it clealy or when I focus on things in the distance. Guys are never going to fall for me!!

I've now been prescribed weaker lenses (-.75 of a difference) and now the lazy eye is getting worse. Perhaps I need a prism to straighten the eye?

Phil 08 May 2006, 03:16

Hi Lisa. Are you worried that your rx will increase? -2.5 is perfect: enough to make you a serious gwg without affecting your life too much. And lenses of that strength look great. How old are you? I was around that rx in my early 20's and increased to -3.75 over the next 30 years.

lisa 08 May 2006, 01:38

I've read that wearing reading glasses can help prevent myopia. Is this true? I'm -2.50 diopter.

What prescription should I wear for reading glasses?

Brille 06 May 2006, 12:10

Fetish Queen: Strong minus lenses.

Julian 06 May 2006, 10:46

Fetish queen: once would have been enough.

fetish queen 06 May 2006, 10:16

've just bought myself a pair of reading glasses -+2.5. I am myopic but find plus glasses kind of sexy, especially since I can't see very well wearing them. It could be fun while making love.

I'm a bit disappointed on the myopia side as was just prescribed a weaker prescription. I can feel myself squinting, but if that's my prescription that's my prescription.

What I find sexiest now, is going out without my glasses on (very blurry) and I am also eager to try out these plus glasses (go to a bar perhaps, and see what guys make of them!).

Also can't wait to make love to my boyfriend. He's only seen me in minus up to now.

Would like to a little survey as well.

Guys, (girls too, if you're that way).

Do you find girls sexiest when:

1. They wear minus lenses

2. They wear plus lenses

3. They don't wear their glasses (if myopic) and squint

4. They do wear glasses for myopia, but they still can't see very well, and have to squint

Thanx for your contributions.

Patrick B 10 Apr 2006, 09:43


It all depends on the person. Lots of teens who are rapidly developing myopia go twice a year for an update. It's not at all uncommon for somebody in this age group to be experiencing increases of 1.50 or more per year For high myopes twice-yearly checkups can be important re the early detection of retinal problems. Lots of people go to the dentist quarterly. Hope this answers your question.

Shelagh 10 Apr 2006, 08:02

Just interested, after reading Patrick B's thread, how often people go for an eye checkup. I thought the recommended period was every 2 years but people here seem to go a lot more regularly than this. Is it solely because people 'know' they need a different prescription, or simply because they like going to the opticians?!! lol

Patrick B 10 Apr 2006, 07:42


Nice to hear that all is well with you, too. You've had a relatively large increase in your prescription over the last year. I remember that your sphere was a bit less than mine but you had a lot of astigmatism. Funny how it keeps on increasing. Mine went up a bit less than yours on the last exam (around six months ago), and I'll be curious to see if it has increased again when I go in later this month. I usually know when I begin to push my glasses up to my eyes more frequently and/or start to use a headstrap to keep them tight for better visual acuity.

Let me know how you're enjoying your new prescription.

Stuart 06 Apr 2006, 18:14


I think the small 10mm bowls, which you and Patribck B describe were often used in really high Rx prescriptions (in the high 20's and above),pre high index lenses to facilitate a thinnest and lightest lense posssible.

Patrick B

Nice to hear from you. Hope all is well. I have a new prescription with an increase in both eyes of -1 and -1.25. This should maintain the same visual acuity, I am told and thankfully my retinas remain healthy.

Stuart 06 Apr 2006, 18:14


I think the small 10mm bowls, which you and Patribck B describe were often used in really high Rx prescriptions (in the high 20's and above),pre high index lenses to facilitate a thinnest and lightest lense posssible.

Patrick B

Nice to hear from you. Hope all is well. I have a new prescription with an increase in both eyes of -1 and -1.25. This should maintain the same visual acuity, I am told and thankfully my retinas remain healthy.

lentifan 06 Apr 2006, 16:51

Does anyone get turned on by these frames as I do?

I don't know quite why. Is it because they remind me of girls I had a crush on when they were popular in the fifties when I was a nipper?

Maybe they remind me of the strongest minus lenses I ever saw. This was the early seventies, by which time they were very old-fashioned. It was in a seaside town; the couple were obviously on holiday and didn't look very happy or prosperous. Husband was a small mean-looking guy, and the wife, who was extremely tall and very thin and hollow-chested, was pushing a pushchair with a child in. She was wearing myodiscs which managed to look very thick while having a tiny bowl, her twinkling eyes minimised almost to nothing. They looked astonishingly strong. This was such a rare sight, I'm sure I stared, perhaps assuming her vision would be so poor she wouldn't notice. But she did notice, and stared back. What she was thinking, who knows?

I knew I found her far more attractive than her husband.

They were an odd couple, what with her very striking appearance and the large height difference between them.

Patrick B 06 Apr 2006, 16:04


Stuart is right. Those lenses were lenticular (myodisc), and I wear them as well. Funny you should mention London, because I saw my strongest myodiscs there in 1978 when I asked an attractive young man for directions in Regent Street. The bowls of his lenses were probably no more than 10mm across in those pre-high-index days. I'd guess that he was at least a -25 and possibly a -30. I was intrigued, of course, because my own prescription was close to his, although I always wore contacts back then.

Hope this answers your question.

Puffin 06 Apr 2006, 03:33

Suspicious, just to say Wei is nothing to do with me. I've better things to do than play fake name games.

Stuart  05 Apr 2006, 21:34


The glasses you describe sound as if they are myodiscs/ lenticulars. Often used for high prescriptions as it allows for thinner and lighter lenses.

They are certainly still around. I wear them. With technolgy they are probably very diffrent and more cosmetically pleasing than the 1970's example you describe.

Tim 05 Apr 2006, 18:27

Back in the 70s in and around Trafalgar Square, London (that's a long story, but if anyone's interested I'll post it!), I was captivated by a lovely girl wearing glasses the like of which I have never seen again before or since. The fronts of the lenses were slightly convex, as usual, and the bulk appeared to be plano or maybe weakish plus, but in the centre there were small bowls like a myodisc, but only pupil-sized, with a very strong minus Rx.

Does anyone know if this type of lens is still made, or know of anybody who wears them?

She had the most beautiful eyes....

suspicious 22 Feb 2006, 15:33

Is Wei a "Puffin" creation?

Wei 22 Feb 2006, 12:11

Do anyone wear 1.9 lens?

 11 Feb 2006, 17:36

Narrow lenses it is. Does anyone know of a cheaper option in the UK than specsavers? Can you recommend a website?

Also, is it better to take 1.74 plastic with antiscratch or 1.8 glass with no antiscratch?

DWV 11 Feb 2006, 11:22


I agree; narrower lenses will give a couple of benefits:

1) The lenses will be closer to being centered on your eyes, which is supposed to look better.

2) The lenses can be made thinner, and therefore lighter.

mattp 10 Feb 2006, 06:28


The plus lenses suit your face very well. Without your glasses, your eyes get lost, but the magnification of your lenses accentuates your eyes nicely. You're one of those people who really looks good in glasses.

For new frames, I'd choose something narrower from side to side. Your face is slim, and the nature of plus lenses is to pull the skin around the eyes outward (as opposed to the cut in of minus lenses). Thus the top half of your face (seen through the lenses)looks too wide compared to the bottom half. Narrower frames where the temples wrap around the front so the lenses cover just the eyes would mean only your eyes would be magnified, thereby keeping the upper half of your face narrow.

Good luck with your choice--Matt

Cactus Jack 10 Feb 2006, 00:23

Julian & Condor: I have been able to link to the last 3 .jpg files using IE6.

Condor: My only suggestion is to shoot the picture again with better face lighting that is brighter with more white. It is hard to see your glasses because the image is so dark. It doesn't do you justice.

I'm not a good judge of frame styles and plus lenses.

Hope this is useful info.


 10 Feb 2006, 00:13

Julian 10 Feb 2006, 00:06

No, sorry. I've tried clicking on the links, I've tried pasting the URL in, I've tried IE as well as Firefox: nothing.

Condor 09 Feb 2006, 22:59

Condor 09 Feb 2006, 22:51

The top one should work okay. This one...

Julian 09 Feb 2006, 18:40

That likn doesn't seem to work, Condor.

Condor 09 Feb 2006, 17:25

I've researched and figure I'll need to go for the highest refractive index I can [expensive :( ] and maybe antireflective coating.

But to justify the cost, I really need to choose the right frames. I've uploaded a picture of myself with my current bullet-proof 5mm oval shaped glasses. Would square frames suit me better (or worse)?

<img src=></img>

Eye Tri 09 Feb 2006, 16:07


I used Transitions lenses for quite a few years, but have gone back to Photogray lenses for outdoor use. What I didn't like about Transitions was that they are very temperature sensitive - they barely change in hot weather. Photogray lenese seem to be much less affected by high temperature, but they are glass and therefore weigh more. I hope this helps.

Wei 09 Feb 2006, 11:23

Bekka ask about Transition lens. I give true reply (more information on unsuitable use for driving on Transition website) . What is problem with my reply please?

no more wei 09 Feb 2006, 10:59

please please please, go away wei, go and bore someone on another site

Wei 09 Feb 2006, 10:55

Post below Wei to Bekka.

Bekka 09 Feb 2006, 10:52

Transition very good I believe except for driving. Will not lighten/darken quickly enough in car. But very good otherwise.

Bekka 09 Feb 2006, 10:22

Thanks. That's right. I am talking about lenses that darken and then lighten automatically.

Sorry to not be specific.


Julian 09 Feb 2006, 10:22

Oops, yes, I think you're right. Oh well; my lenses are that as well!

myofan 09 Feb 2006, 09:41

Julian, I think Bekka is talking about lenses that darken in bright light, and not blended lenses (so called "no line" bifocals). "Transition lenses" may be a US term, but I'm not sure.

Julian 09 Feb 2006, 09:00

Bekka: I've worn them for fifteen years, and am perfectly happy with them, but other people will tell you a very different story. (Mind you, I wore bifocals for ten years before that without problems, and not everybody would say that either.) For two purposes they are not so satisfactory: one is working at the computer (though I'm wearing them now); the other is reading in bed, for which I always change into a pair of single-vision readers.

Bekka 09 Feb 2006, 07:47

My boyfriend (definitely OO) is after me to get transition lenses. When a transition lens commercial comes on television, I can see him leaning forward, after which I always hear "you should get those lenses." Anyone had much experience with them? I have heard positives and negatives.

Thanks in advance.


Condor 08 Feb 2006, 17:48

I'm about to get new glasses and I've got a +7.5 perscription with lenses that measure almost 5mm and their widest point. I was hoping someone could advise me.

I can get "aspheric" lenses for £30. Or 1.67 aspheric for £110 or 1.74 for £150? Is this number something to do with the refractive index for glass? If I recall, regular old glass has something like 1.54 refractive index... how do I know how thin they will be?

The price list is at (I need basic single vision...

Katy 24 Jan 2006, 13:52

Wei - around -8.

Cactus - exactly :-) The lenses look like bug-eyes..

..but they claim you can: "wear them in public with total confidence. Quite possibly nicer than any pair of sunglasses you've ever owned". Hmmm..

Wei 24 Jan 2006, 13:07

At what rx do lens become plano fronted?

Cactus Jack 24 Jan 2006, 09:24

Katy: Pinholes can be useful at times just as squinting can be useful. In fact, your eyecare professional probably has some and has used them on occasion as a diagnostic tool to see if correction is possible.

The reason pinholes work is related to optical physics, lens aperatures (f stop on your camera), and depth of field.

The primary long term benefit to the pinhole glasses offered by this web site will be to their bank account.

P.T. Barnum would be proud. If the web had been around in his day, he wouldn't have bothered with the circus.


Katy 24 Jan 2006, 08:02

Has anyone else seen these? "Insta-Focus Glasses - one pair suits any prescription". The only problem is they "are best used when seated or standing still" :-)

shashank 17 Jan 2006, 09:55


contect lens


optical work

optical manager

cliniucally work in eye hospital



RL 13 Jan 2006, 09:56

I picked up the 1.67 high index glasses. They have plano fronts but with the anti-reflective coating they don't reflect too much light. They look very cool and the vision is good too.

Wei 03 Jan 2006, 11:12

I surprised that myodisc avilable in -6! This cannot be common lens choice for -6?

I too find that unblend myodisc very good for all situation apart from driving due lack periparial vision. I perhaps adjust eventally.

Bowl for -30 must be very small?

RL 02 Jan 2006, 11:27

I wear unblended myodiscs at -14. Mo problems. I do have some high index 1.67 lenses on order. I am eager to see how they work out.

JKD 02 Jan 2006, 09:03


I wear unblended lenticulars (myodiscs)

od. -30.00. os. -31.50 and have no problems with them at all.

Myopwolf 02 Jan 2006, 08:58

I've read an article short time ago: lowest recommendation of opticians is -15, but available from -6

Wei 01 Jan 2006, 14:06

Do any one know lowest rx for recommenation of myodisc? I think maybe -14?? Maybe in past was lower before hi index??

Wei 28 Dec 2005, 13:36

Do any person wear unblend myodisc here? What is your experinece of the lens?

Brille 21 Dec 2005, 12:29

Thanks, I may try this. The new frames would be smaller and if the lenses are in excellent condition, I see know reason to pay for new ones.

Puffin 21 Dec 2005, 08:13

They do this with glasses given to charity for poor people.

Julian 21 Dec 2005, 06:31

Brille: it's possible as long as thew new frame is no larger than the old one.

Brille 21 Dec 2005, 02:12

Can lenses be installed from one frame to another?

I was wondering if existing lenses from one frame can be recut, reglazed and transferred to a new frame.

sam12744 13 Dec 2005, 11:56


Hi-index wasn't as common 10 years ago.I wear glasses with base-out prisms and opticians have ground down the sharp edge (at the thickest part) of the lens to reduce the thickness a little.This might take a mm or 2 off the thickness at the outer edge; it does slightly reduce the benefit of the prism and the corrective lens,but only at that point,though not really enough to notice when wearing them(its not as drastic a thing as you imagine and doesn't go far back into the lens).Its literally just shaving a fraction off the edge.

Katy 13 Dec 2005, 08:25

My boyfriend tells me that about 10 years ago he went for some new glasses to D&A, and they said that as they would be quite thick they could cut down the lenses all round the edges, so that the prescription part would only be in the centre, and the edges would be plano. This sounds to me like the same idea as myodiscs, but he is only -6. They told him he would only be able to see through the middle of the lenses, but they would be thinner. Has anyone else heard of this? Was there no hi-index then? It seems to me a bit drastic for an rx like that, and presumably there would have been a visible circle on the lens. He chose the normal lenses and they turned out to be 7mm thick.. now they have found their way into my collection :-)

Kathy 01 Dec 2005, 22:21

I think that frameless refers to the drill mount rimless frames. I have a pair of Chanel 2014's that fit that description. There is no frame because the lenses are attached to the temples. The frame is lightweight and looks very nice with a/r coating on the lenses. Silhouette and Marchon also has a frameless pair of glasses too. The Silhouettes are very popular because they are hingeless also. My co-worker has a pair of those and they look very nice.

Filthy McNasty 01 Dec 2005, 20:10

I understant you to be describing "rimless" and "semi-rimless". I am not familiar with "frameless," which is not to suggest that I am right.

daffy 01 Dec 2005, 18:51

Rimless are sometimes considered as frames that have no bottom part ( the use of the fishing line).

Frameless are the ones that have no frame around the lens.

I thought the same before as well, but after seeing some peoples description on web sites and ebay, the above statements is what i conclude.

Julian 26 Nov 2005, 23:42

What's the difference between 'rimless' and 'frameless' glasses?

Frustrated 26 Nov 2005, 17:44

I received my prescribed progressive glasses today, and I’m able to find clear points when I gaze in one spot, however, the overall image is somewhat blurry. How long does it take to adapt to these these types of lenses, or is the placement of the add portion of the lenses incorrect? My distance correction is L-7.5 and R-7.25 with an add of +2.0 in each. I’m 54 years of age and a first time wearer or multi-focal lenses.

LikeGlass 24 Nov 2005, 15:49

As with rimless, frameless glasses also use thicker blanks as the lenses must serve as the frame as well.

Clare 24 Nov 2005, 13:22

I've seen those, but mine are kind of stapled, they're the hingeless sort.

Likeglass 24 Nov 2005, 06:34

Oh, Rimless! They use thicker blanks so they can fit the support strap in a groove around the lens. (the little piece of fishing line.)

Clare 23 Nov 2005, 22:44

Of course it was 3mm, how stupid of me. I was talking about rimless which I guess is more obvious.

Hey George1968, I'm good, hope you are too!

LikeGlass 23 Nov 2005, 19:22

Heee! Yea, I didn't even see the "C" !

3mm is still about 1/8 inch. I have a friend with that rx, and the lenses look more like 1/16. (very little lens in front of or behind the wire frame.)

Julian 23 Nov 2005, 18:02

...or of course it might be 3 mm.

LikeGlass 23 Nov 2005, 17:51

Lens size and thickness are related. if the lenses are wide even a low rx can start to get thick. Also, if there is a little prism, they can grow as well. If you want super thin, stay with high index in a small frame size (both horizontal and vertical.) One other factor can cause this: if the distance between your pupils is lower than average, the centers of the lenses will be set at that point and you may end up far out on the lens blank by the time it reaches the side edge of the frame.

George1968 23 Nov 2005, 14:33


3cm thick? I have rimless and my prescription is stronger than yours and the lenses are not nearly that thick. Are you sure about 3cm?

How are things going? Still going bare-eyed on the weekends?

Clare 23 Nov 2005, 13:44

I see SO many really thin rimless lenses. My -2.75s are 1.6 I think but still 3cm thick at the edges (thinner in the middle though). How can this be? Are the thinner lenses higher index than mine? Mine look pretty thick and chunky by comparison.

Wei 07 Nov 2005, 10:54

I too had many problem of glasses slipping so happy new glasses fit better. I have also blend mysodisc but distortion can be great i think.

Wei 05 Nov 2005, 04:13

Comment on non blend mysodisc very interesting. I also try belnd mysodisc but suffer more problem for distortions.

Sam12744 05 Nov 2005, 03:43

I wear non-blended myodiscs.Of course,they are not as cosmetically pleasing,but the vision is good through the bowls.The thing about non-blended myodiscs,is that,thanks to the small bowls,there is little distortion(I have base-out prisms),but you do have to accept that your field of vision is restricted.I can, therefore, relate to Bobby's comment about having difficulty parking! I can see straight ahead really well and read a numberplate at more than the required distance,but driving with that restricted field would be a worry and you can only twist your neck round so far!

At such high prescriptions,the slightest slip of the glasses down the nose causes a significant deterioration in vision,so they have to fit really well.

JM 05 Nov 2005, 02:00

I always wear non blended myodiscs, most probably from habit over the years. The blended ones are much better from the cosmetic point of view but so much more expensive.

Bobby 04 Nov 2005, 13:32

I used to have non-blended myodiscs of -20 dptr. The ywere for my GOC (glasses worn over contacts) I wore them scarcely, about once a week. They were quite comfortable, my vision was good. The only problem with them was, that I had some problems while parking my car.

I have blended myodiscs now. They are very good, I love them.

Wei 04 Nov 2005, 12:37

I find now after using of differnt glasses non blend myodisc is best for vision i think. Lesser problem of eye looking from bowl evident. Do any other person find this also or wear non-blend mysodisc?

woodframes 07 Oct 2005, 21:36

Good day,

I am a maker of hand carved wooden glasses, each being specific in design and construction to the desires of the customer. I personally pick all my woods to ensure uniqueness and quality. If anyone is interested in a one in a kind pair of eyewear, feel free to contact me as we could discuss further the possibilities of custom wooden frames.

Scott Urban

Wei 21 Sep 2005, 10:16

Jo I try if offesive person apologize post picture very soon. Do you wear myodisc also?

I very interest know of how many person wear myodisc. Sighting is rare but many of high rx wear contact i think. I have contact also now and give good vision. I have also blend and non blend myodisc but finding non blend myodisc better vision but looking worse!

jo 21 Sep 2005, 08:36

typical es fashion.

X comes in. Post a lot. Promises to post pics soon when they gets hold of a camera or scanner. Y comes in. Offends X. X disappears. A-W left hanging with mouth dry.....

Hope this doesn't happen to Wei, since i am still hopeful to the prospect of someone promise to post images of themselves in their hi rxs and actually doing that.

Wei 20 Sep 2005, 11:50

I very confuse on what you say about me! I post more soon maybe.

I wear non blend myodisc recently whicth little better for acuity than blend myodisc. I interest to learn who else wear non blend myodisc also.

Julian 20 Sep 2005, 02:30

Oh come on Derek, that post was a fortnight ago.

derek 20 Sep 2005, 00:07

Thought Wei was going to give us a break and post less, guess not

QT 19 Sep 2005, 23:58

What is the diffrence between

a multi focal lens ,progressive lens

and a vari focal lens?

Wei 06 Sep 2005, 10:25

Curious, yes I try post picture soon. I not have camera now but will try soon I hope.

Curious 06 Sep 2005, 05:03


why don't you post us a nice picture of your new myodiscs?

Wei 30 Aug 2005, 08:23

Thank you RL. I think 1.9 index worth expense for improve aciuty, if rainbow effect not too distinct. I very disappoited with myodisc, due to small visual area. I very much like contact but I want glasses that are not problemtic too!

RL 30 Aug 2005, 08:00


1.9 lenses are, of course, very expensive and they sometimes suffer from chromatic abberation (a rainbow effect when you are not looking right through the center of the lens.) They would probably be less than 8mm thick though. So, it's a trade-off. Check with your opitcian.

Wei 30 Aug 2005, 03:09

I try persist with myodisc but am thinking other altertive, maybe 1.9 index. Do anyone try 1.9 index and know how thickness would be with rx -16D?

RL 29 Aug 2005, 19:33


The current ones came from Lenscrafters and I have had them for maybe three years. The first ones that I got were in the late seventies and I think they came from Superior Optical Co. They were glass and had a plano carrier. The Lenscrafters variety are made from CR-39 and are ground on a plus carrier. For mine, which are -14, the bowl size is 28mm. They fit well and the vision is great.

-14 29 Aug 2005, 18:13


I was wondering how long you have had myodiscs and where you purchased them (on line)?

Wei 29 Aug 2005, 12:58

I try with myodisc but still have aciuty problem. I try keep lens close to eye but I am not happy I fear. I keep trying for some time but is difficult. I wear contact most time now but I fear myodisc is worse than old thick glasses.

RL 26 Aug 2005, 07:34

Wei, The trick with myodiscs is to wear then very close to your eyes, This puts your eye right in the bowl and allows for the sharpest vision. With minus lenses, the closer to the eye the better. I am a -14 and have both myosiscs and regular glasses. I like the myos for their lightness and when they are worn close, I don't even notice the bowl effect.

Stuart  25 Aug 2005, 23:34


Persist and you will get used to the myodiscs. I find that I instinctively keep my eyes centred in the bowl and move my head as required wityhout thinking now. It took me about 2 weeks and one near fall when going down a staircase when I was disembarking from a plane onto a tarmac, and I had been wearing Cls for more than 20 years.

Much the same with the cls, it is worth the effort. I had a real ritual for insertion and removal with all equipment at hand and rarely had any problems if I was prepared and everything in the right place.

Good luck

PatrickB 25 Aug 2005, 16:50


I hope you're seeing reasonably well when you look straight through your new myodiscs. As Stuart and I have said all along, myodiscs are not a cure-all for all high myopic problems. They have their limitations, e.g., a lack of peripheral vision. You will get used to them in time and certainly enjoy their lightness and relative thinness. You're probably smart to get used to them now since you seem to be heading toward -20 which is generally thought of as the time when myodiscs become a necessity rather than an option. Also glad that your new contacts are working out. Keep us posted!

Wei 25 Aug 2005, 09:57

I get new myodisc finally. Lens is light and not very thick but I not very happy with aciuty. I have try several day to acomdate but still I have problem seeing well and must turn head very much to see. But I am hopeful of improvement soon if adjustment is made.

I have also contact now which is much better I think. I see very well with contact and can put in eyes with no problem.

Katy 19 Aug 2005, 02:43

Thanks Tod & Sandy :-) It sounds like it is worth getting the polycarbonate for the strength - maybe from somewhere cheaper though!

Sandy 18 Aug 2005, 19:46

Katy, I have a pair of Marchon Airlock 2's that I am currently wearing. I had a choice of either polycarbs or trivex lenses. The polycarbs for the glasses were $159 and the trivex was $199. I ended up choosing the polycarbs with edge polishing and a/r coating on the lenses. They are very lightweight and almost invisble. I have no regrets on spending almost $450 for my last pair of glasses. Take care.

Tod 18 Aug 2005, 17:30

Katy, I have worn semi rimless glasses for years. My first pairs I got from Sterling Optical and the lenses (CR 39) would flake off at the edges where the groove is for the nylon cord which holds the lens to the frame. I was always returning for new lens replacments. Well after some time, many replacements which were not all under warranty, I then went to Lenscrafters for new glasses and they would only make semi rimless or rimless in polycorbonate. So yes, polycarb is more $$ but it is many times stronger than any other lens type (there is one other type that is as strong as polycarb, I forget the name) but it is also the safest lens to wear. Hi Index is polystyrene, I believe. It is very brittle so its best to wear it in a full frame, preferably a plastic frame.

Katy 18 Aug 2005, 15:01

Does anyone know about the use of different lens types for rimless frames in terms of the strongest / least likely to break, apart from polycarbonate? My local discount optician offers CR39, 1.6 and 1.67 index lenses for similar (cheap!) prices, but charges a lot extra for polycarbonate. I think I heard somewhere that high index lenses are more brittle but not sure! Thanks :-)

Stuart  10 Aug 2005, 16:35


Glad to hear tht you have found our comments helpful. Similarly I had the same expereince and Patrick's experiences and patient explanations were really helpful to me!! It is good to know that you are not alone and that others have the same problems.

I am sure that the myodiscs will be the best possible solution from every angle. Do you have a plus or minus carrier in the lenses? As you have been wearing glasses you will be accustomed to keeping your eyes centred and will not find you eyes straying into the carrier as much as I did (after 20 years of wearing cls), although now I am quite used to it.

Regarding Rx increases the main thing is that your eye health remains good or so my doctor says when I question / him about the middle age increases I am having. I had hoped for a slight decrease.

John 10 Aug 2005, 07:48

Stuart and Patrick,

Sorry to be so long getting back to you. Your advice was invaluable - thank you. Bi-concave lenticulars now on order and I should have them in a couple of weeks. Will let you know how I get on with them. In answer to the question on the progression of my myopia, it certainly didn't stop when I was 30, as I was always told. I have hardly ever gone a year without an increase of between -0.50 and -1.00. Having said that, the increases I had in my teens were far more.

Geoffrey 09 Aug 2005, 11:43

Julian and others, you are right about + lenticulars restricting peripheral vision, they really do. As you said, steps are a pain, and especially escalators too. I use my cane to help as my depth perception is quite poor since i really only use one eye for most seeing.

I am going to a new low vision doctor (the old one retired) in a few days for an evaluation of possible GOC using a RGP aphakic lens supplemented by glasses. I have tried hard and soft lenses before with no success. The doctor says the RGP could be a solution.

 07 Aug 2005, 15:44


I agree with you. Within the last six months I saw a post on this site about someone having seen a very good-looking young man of around 30 who was wearing plus lenticulars and the obvious difficulty he was having walking down a flight of stairs. I've seen that as well on the rare occasion with a high minus, although I have been told that high plus lenses are much harder to get used to than high minus. I'm thinking of that young Brazilian fellow, 4Eyes, who has so much trouble with his vision and who has extremely high plus bifocal glasses. He also has other visual problems -- all of which I can't recall -- which brought him to the UCLA Med Center. Any lenticular lens requires some getting used to and has ome permanent downsides.

Julian 07 Aug 2005, 12:54

I'd expect high hyperopes to have the same problem, especially if they wear lenticulars.

Patrick B 07 Aug 2005, 10:27


Specs4ever is right; however, he is creating his myopia as part of a glasses fetish and doesn't do it fulltime so his visual experience is different from yours and mine. Similar, of course, but different in that he can turn it off whenever he wants to and probably hasn't subconsciously trained himself to look only directly through the bowl since he doesn't wear glasses fulltime.

You should get (as I believe you have) the blended myodiscs. Why? Because they are better-looking cosmetically and secondly, because you will have no problem adjusting to them. Because Stuart went from fulltime contact lens wear to fulltime myodisc use, he had to learn how to cope with the somewhat limited viewing area. I had the same experience when I began wearing glasses again nearly three years ago. You are already coping with a limited viewing area in your -14s since you primarily look through the center of your lenses where the best distance vision is located. You're probably doing it without realizing it. Therefore, when you look through your myodiscs your eyes are already "trained" to look through the dead center portion of the lens and they won't have a tendency to stray far from the bowl to the blended transition zone or to the carrier itself. Haven't you noticed how highly myopic people sharply turn their heads to see something off to the side. Non-myopes or low myopes don't have this worry since they already enjoy good peripheral vision.

Don't worry and enjoy your myodiscs when they arrive. Let us know how you like them.

specs4ever 07 Aug 2005, 09:24

Wei, I posted as good an answer to your question as I could on July 31 - see my posting.

Wei 07 Aug 2005, 09:19

Sorry if I become repeat but I wonder if anyone give advise on types of myodisc lens. I think of blended or non blended lens. I see of course that blended myodisc look nicer but does anyone know if advantage to non blended type? Please anyone give advise. Thank you Wei.

Wei 06 Aug 2005, 10:43

I interested in posts on myodiscs as I get myodisc soon. Is adaption period long? I understand I must train eyes to use bowl and stairs may be problem in beginning. I think myodisc worthy due to light weight but am hopeful they not give me other problem!

Stuart 03 Aug 2005, 20:30


Patrick B has really summed it up well. I am also very pleased with their weight and thickness and to most peple they are not noticeable.

After more tha 20 years of continual wear of CLs. and a few weeks of under prescribed glasses whilst I waited for new ones it is difficult for me to comment accurately re peripheral vision. I am training myself not to allow my eyes to stray from the bowl/ centre of the lense with more and more success. With a minus carrier you do have some vison although blurry, if your eyes stray outside of the bowl. It is only in this area that I have encountered any difficulties unique to the myodiscs.

All in all it is a good solution for me and my Rx.

I have had some reasonable increase in my 40's in Rx including astigmatism and the doctor thinks it quite likely that I could have a further period of increases.

 03 Aug 2005, 20:23


-16.00 mysodisc lenses are not thick at all.You probably meant -16.00 myodisc lenses-well those are very-very-very thick.

Wei 03 Aug 2005, 14:18

Does anyone know how thick is -16 mysodisc? I have -14.50 ho index but they are thick still. Will mysodisc make difference for my rx?

Wei 03 Aug 2005, 09:56

I read posts on myodisc but do not know if thias is the right answer for me. Is there other solution to my thick lens problem. I know -16 very bad but the lenses is very heavy and I do sdo know if mysodisc can be made in -16. Are they for only -20?

Patrick B 03 Aug 2005, 08:03


Glad our advice was of some use. I'm pretty hopeless with metric equivalents, but I would say that 6/12 is the metric equivalent of approximately 20/40. I believe that a meter is around three feet, so multiplying that three feet out by 6/12 would give the basic equivalent of 20/40 feet which is essentially my corrected visual acuity with glasses. I haven't had 20/20 vision with glasses since I was around a -12. In a well-lit room or outside on a bright day my visual acuity is arouund 20/30 (6/9?) Stuart is around the same, I believe. I don't know how old you are, but Stuart and I have both experienced some increases in our myopia in middle age. I went up five diopters in my twenties and recently mine increased again by -.75 and -1.00 giving me a new prescription of -23.75 and -26 which is similar to your own prescription but without the astigmatism. A -.75 increase in six months is a fairly large increase at your level. What has been your course of myopic progression? Did most of it occur while you were young or are you experiencing some large increases as an adult?

Anyway, I think you will find the lenticular (myodisc) lenses a real plus. Stuart and I have got biconcave lenses (with negative carriers which I think are cosmetically superior and less off-putting when your eyes stray from the bowls). The blended bowls are 20mm. When viewed from dead-on you the myodiscs aren't all that noticeable. They will show somewhat when viewed from the side, but most people simply don't notice. As I type this posting wearing my old -22/-23 "readers" I am so much more aware of the peripheral distortion than when I'm wearing the myos. When I look into the distance (blurrily!) I notice how much more distortion there is with the skyline as it slopes down on the edges. I adjusted to the myos immediately since I was always making a real effort to look only through the dead center of my old glasses to minimize the distortion effect. You'll also like the way you look. I was rarely caught out in these old glasses because they are so thick and my eyes and face are so distorted behind them. I'm sure you've experienced the same thing when you see yourself in a mirror.

Hope this helps. Let us know how things go.

John 03 Aug 2005, 04:01

Thank you to everyone who offered advice. It has been very helpful and given me food for thought. My myopia is of the 'progressive' type and this time it increased by -0.75 in each eye and my astigmatism by -0.25. My visual acuity is 6/12. I am not sure what the U.S. equivalent of that is. As my myopia has worsened and my lenses become thicker, I have found more, what I can only call, distortion when I am not looking directly through the centre of the lens. Will lenticular lenses help this?

Stuart  31 Jul 2005, 16:57


Just concurring with Patrick B. I have had my first pair of myodiscs now for a fortnight. I delayed getting them as long as possible and with hindsight they are I believe, the best possible solution once your Rx is over 20 and I should have gone ahead earlier.

They are lighter ( it surprises me) and definitely thinner. They do not give me 20-20 corrected vision but that is to be expected at my level of myopia.

You do have to get used to them. My eyes still stray out of the bowl into the blurry minus carrier ( if you have plus carrier you would see nothing)and they have to sit just right on the nose. Descending stairs is a little precarious - but all in all there are not many alternatives as I can't wear contact lenses any longer.

If I were you I would ask the specialist/ optometrist to possibly refer you to someone with more experience with myodiscs. I personally found the varios threads on this site helpful and it certainly "de-mystified" the whole process.

Good luck and just post if you have any questions.

Patrick B 31 Jul 2005, 16:01


There has been a lot of posting by some very high myopes to the Guys in Glasses and Glasses over Contracts threads. Stuart, Thomas and I are the highest myopes followed by HMG, Ricky, Tinyeyes and others. Stuart and I both have prescriptions well over -20. Mine is OS-26 OD-23.75 with no astimatism. Stuart's is posted somewhere in Guys in Glasses, and he has quite a bit of astigmatism. Both Stuart and I have biconcave lenticular lenses in 1.8. Our bowls are 20mm. Neither of us went with the plus carriers which have the advantage of being thinner on the edges but, I feel, have more carrier distortion. I think the negative lenses simply look better because the carrier is less noticeable since it isn't a plus juxtaposed against a very high minus bowl. Anyway, both of us have around 20/30 to 20/40 vision depending on the light and how tighlty our glasses are up against our eyes. What sort of visual acuity have you got and how much of an increase did you have in your last prescription?

Keep in touch and best of luck with your new glasses. Your doctor is probably right to put you in lenticular lenses.

specs4ever 31 Jul 2005, 10:29

Here are some lenses in approximetly your prescription. The super lent is the blended one:

specs4ever 31 Jul 2005, 10:27

John, I am a high myope pretender, but I have had a lot of experience with lenticular lenses, as well as with regular myodisc lenses. The one thing I like about the regular myodiscs is that once your eye hits the circle you know that your vision stops there. With a blended myodisc you have an area around the edge of the circle that is all blurred. The blended myodisc lens does look a little better as far as the appearance from the front goes, but it requires a bit of adapting to. For a prescription such as yours I prefer a 1.9 hi index glass lens from someone like Zeis.

Julian 30 Jul 2005, 22:44

John: there are several high myopes who've been discussing this kind of question on the 'Guys in glasses' thread over the last week or two. It might be worth re-posting there, though there's a good chance one of them will answer your question here. In any case you'll get some information if you read the recent posts overe there.

John 30 Jul 2005, 10:05

I had my six monthly check up a few days ago. My myopia had increased not much more than usual but it was suggested to me that I would benefit from lenticular lenses. It seems they wouldn't need to be so thick, there wouldn't be so many rings and they would be lighter in weight. Also, she thought there would be less distortion. What worries me is that she didn't seem to have much experience of them. She will not bw able to show me an example of these lenses for at least a week but, it seems, they are very expensive. Has anyone any experience of lenticular lenses? My prescription is LE -24.50 -3.25 RE -23.75 -4.00.

 26 Jul 2005, 11:12

Can anyone help, I've always really had a thing for glasses and before needing them I used to wear reading glasses but really wanted a pair of minus distance glasses and I guessed I might be able to see out of them anyway when I was 20 I got the courage to go and get an eye test and blagged the doctor and got a pair -0.25 in both eyes I really didn't need them as my eye sight was near on perfect but she thought they would help me with head aches I said I got, anyhow as time went on I wanted to get stronger lens but my dream started coming a bit too true and five years down the line I now really do need glasses, I have to say now I don't want to need them well not this much buy hey its happened, I don't know if I should blame my self for wearing glasses when I didn't need them or computer use maybe a bit of both it may not sound much but I'm up to -1.25 in both eyes and my distance vision is not good at all now and its affecting my life, problem is I don't wear them out as the glasses thing is too much of a fetish I just can do it, Right OK I'm going to get to the point now, I've now got a thing for + glasses but can't really see at a distance through them, I did find some weak ones on line +0.25 which I wear for the computer at home, but what I really want now is distance glasses with a + add I've found a shop on line where you just put in your prescription but don't have to send the real thing, so can anyone suggest a prescription i.e.: -1.25 add + 0.50 I don't have anything else on my normal prescription its just -1.25 in both eyes and nothing else so how much of an add do you think would be ok? bearing in mind I do want to see out of them clearly for close and near, and you never know I might start wearing them to work!

tortoise 13 Jul 2005, 12:24

Dave D, It means each lens is 56 mm in width. Yes, that's pretty big.

Dave D. 13 Jul 2005, 12:14

Hello Everyone: I have a quick question. What does a lens size of 56 indicate? Is that a big lens size?

Thanks in advance for responding.

Filthy McNasty 14 Jun 2005, 14:57

The two are not mutually exclusive - the former describes the substance of which the lens is composed, and the latter describes one aspect of the curvature of the lens. Quite apart from the product lines offered by any given manufacturer, it is quite possible to have aspheric lenses in polycarbonate, CR-39, glass, or any transparent material you wish.

MB 14 Jun 2005, 13:36

Has anyone ever had trouble adjusting from a change from polycarbonate to aspheric lenses?

Daffy 26 May 2005, 19:09

I don't think that hi index lenses are required for up to say -3. But the stores will have you believe that even at -1 it is benificial (but what they don't say is that it is more beneficial to them - financially!!!)

Katy 10 May 2005, 14:53

That first one says that high index lenses mean less cut-in - I always thought it would be the same, as the effect of the lens on the light is the same :-S Does anyone know about this?

 10 May 2005, 14:48

cool - thanxs. Does anybody have a break down of which index lenses are suitable for each prescription. So, e.g, what is the prescription that high index lenses are recommended? and how does this index number change with the dipter increase?! Cheers!

-- 10 May 2005, 14:03

and this too:

-- 10 May 2005, 14:02


-- 10 May 2005, 14:01

this page sort of shows the difference

 10 May 2005, 11:47

Anybody got any pictures of high index lenses compared with ordinary plastic ones? I would love to see the difference between the edge thickness - do high index lenses imrpvoe 'coke bottle effect' and cut-ins? or is it just edge thickness which is dramatically improved?!!

 07 May 2005, 22:03

Danny 25 Apr 2005, 12:30

Car problems this morning so spent 2 1/2 hours wandering around a nearby town whilst car being checked over.

I spent a few minutes (lol) in 6 different opticians finding out the price of Zeiss 1.9 hindex varifocal lenses in my rx (wwhich I had in my pocket)

The cheapest was £350 in one hop and £467 was the most expensive! for the same lens??? guess which shop is making most money on poor unsuspecting customers>

-14 22 Apr 2005, 14:05


Right now I am wearing blue tinted lenses with gold AR. No splotches or crackling. I also have sunglasses with AR. My best friend is an optician who once worked for Lenscrappers and he says if you go for their one hour service NEVER get the AR they offer.

wintertales 21 Apr 2005, 23:05

i purchased from Lenscrafters glasses with a blue tint, then took it back to have anti reflective coating applied. when holding the lens under a light fixture, ar coating facing up, i can see huge splotches on one lens, and a continuous spider web/crackling on the other. i took it back, and was told it would be replaced. on the same day, i received a voice mail saying you can have both a tint and ar coating, but the result will be the same (splotches), and that i must have either tint or coating, but not both. does anyone have both tint and ar coating without the splotches. is Lenscrafters being truthful? any response would be appreciated

Dr.S. 20 Apr 2005, 06:59

Comments on two previous posts. Blended myodiscs have the sharp edge where the prescription bowl meets the outer non-prescription part of the lens rolled or smoothed off, which tends to reduce the amount of visible ring(s) that would normally be seen from the front. Cut-in is a purely geometric effect that is not affected in any way by the refractive index. The job of a lens is to bend light - high index lenses simply need less curvature to get the same bending, so they are thinner. The amount of cut-in is strongly affected by the lens size (distance from the optical centre to the outside edge) - bending is more, the farther you are out from the centre. Cut-in is also affected by the distance from the lens rear surface back to the cheek - very short distance produces less cut-in for any lens size and power. This is just one of many reasons why a highly myopic person who wears glasses may want to wear the lenses just as close to their eyes as they possibly can manage.

Puffin 20 Apr 2005, 05:37

Visitboy, I've been wondering about that question for some time too. As I don't wear glasses, and don't possess any, I can only deduce from what I see.

It seems to me that yes, there is less cut in, but, modern frames being generally smaller and closer to the eye make cut-in less anyway. Exactly how much less, I'm not too sure, and also, it depends on the rating of the high index material. It's difficult to tell from one photo alone - perhaps find someone who has both and do some measuring, if they'll let you.

Stingray 20 Apr 2005, 05:03

What is meant by blended myodiscs? How can you tell if you have a pair of glasses with these types of lenses in them? I have a pair of at least a -16 glasses that I am putting up on ebay this weekend and kind of think they may be these blended myodiscs. Thanks.

Katy 13 Apr 2005, 10:49

That is interesting.. there are lots of links from that page to other BBC pages on vision, which then all have their own links. This one is about a cure for presbyopia -

VisitBoy 13 Apr 2005, 08:43

Hmm. No-one knows the answer to my cut-in question below. Intrigued!

From today's London Standard Lite:

"New lens could end short sight"

SCIENTISTS have designed new contact lenses which they hope will make short-sightedness a thing of the past. The team at Anglia Polytechnic University hopes to give children from the age of five lenses to wear which will help them focus and should stop them developing myopia and, later in life, cataracts and glaucoma. Nick Astbury, of the Royal College of Ophthalmologists, said: "We welcome any research that might help in this area."

See for more detailed coverage of the same story.

VisitBoy 04 Apr 2005, 06:50

OK, so we've talked about rings.... I've been wondering about cut-in. Is there less cut-in on a high-index minus lens, or is it just the same as standard index?


Brille 01 Apr 2005, 02:05


I think that a higher index lens will have the same amount of rings as a lower index if viewed from acute angles. The difference is the rings are compressed.

Brille 01 Apr 2005, 01:56


Bi-concave lenses are usually thinner. A -18 bi-concave would be quite thinner than a -18 with a flat front. If I were buying CR39 lenses beyond -16 I would always choose bi-concave.

 31 Mar 2005, 17:22


AL 31 Mar 2005, 16:33

Plano in my prior post has a flat front. The "pipe" sign posted as a dash for some reason.

AL 31 Mar 2005, 16:32

)) = Normal

)- = plano

)( = Biconcave

lentifan 31 Mar 2005, 15:51

Puffin, do you mean bi-concave lenses are thicker or thinner?

Puffin 31 Mar 2005, 14:53

Lenses that curve inward front and back - unlike the more common ones which only have one inward (concave) surface and one sticking out or flat surface (not counting the edge, of course). It does a great deal for lens thickness, apparently.

STINGRAY 31 Mar 2005, 14:28

What is meant by "bi-concave" lenses when they refer to myopic lenses? Anyone who has an explanation in no so technical terms would be appreciated.

guest 28 Mar 2005, 17:46

So, lenses of the same prescription but different index might not have the same number of minus rings? Low-index materials will have more rings then?

slb 28 Mar 2005, 14:18

Its definitly to do with internal reflection within the lens.

The surface involved is the back of the lens (nearest the eye), and as you go to the edge this gets at sharper angles to the axis. At a critical angle (dependant on the refractive index of the two materials (lens and air)) the back surface goes from mostly refracting to reflecting, and so you see the image of the side of the lens.

(couple of physics degrees but not particularly in optics)


Filthy McNasty 28 Mar 2005, 13:27

You can demonstrate that the white rings are actually the reflection of the edge of the lens by making a mark on the edge with a non-permanent marker. All of a sudden, the rings will all have a black mark in them.

Bart 28 Mar 2005, 13:14

Obviously my answer has nothing to do with Maggie's one.. :)

Bart 28 Mar 2005, 13:00

I'm not a phisician, but the circles are caused probably by the minification effect of these lenses, being thicker at the edges and thinner in centre. The circles are probably the effect of "stretching" the lens edge, pushing it more and more distant and becoming so smaller and smaller. So each circle is, in my opinion, the lens edge minificated gradually by the lense power.

Maggie 28 Mar 2005, 12:54


When light waves (or any other type of wave for that matter) pass from one medium (material) to another part of the wave is reflected and part is refracted i.e. it carries on through the second medium but it's direction is altered. This is in essence how lenses work. with a lens the two mediums in question are air and glass (or plastic). The greater the difference in refractive index between the two materials the greater the amount (angle) of refraction. Hence hi index lenses refract more for a given geometry. Anyway I digress. What you are seeing with power rings is the light being progressively bounced back and forth within the lens and each time it meets the lens/air boundary some passes through and you see a ring and some is reflected back into the lens and some is then bounced back hence another ring offset from the first and so on ad infinitum. It's known as internal reflection. Sorry but it's very difficult to explain without diagrams so that probably sounded even more confusing.

Curious 28 Mar 2005, 12:00

Thanks, Julian. If anyone has a more detailed explanation, I would like to know it. I've dated other nearsighted girls before, but never anyone whose glasses formed those circles. She's 21 and says her eyes are still getting more nearsighted. Does that mean her future glasses are going to have even more circles? I don't mind the circles, and I actually think they're pretty cute, but I was wondering where they come from. Her eyes also look pretty small through her glasses and the lenses seem to take a chunk of her cheeks away. Those are cute phenomena too. I just don't understand them. Thanks.

Julian 27 Mar 2005, 23:31

I think it's something to do with internal reflection and refraction of light in a strong minus lens. Maybe somebody whose physics is more up-to-date than mine can tell you more.

Curious 27 Mar 2005, 21:54

Doesw anybody know why glasses for nearsightedness form these concentric circles? I'm dating a girl who's pretty nearsighted (-9) and there are a half dozen or so circles around the rims. They're sort of interesting to look at but I have no idea why they're there.

4eyes 27 Mar 2005, 18:51

I am using bifocal for almost three months now and I´m trying to get used to them. I have +25,50 and +25,75 longe(Up) with +30,50 and +30,75 perto (bottom) with 15º base externa (BO). My problem is: the +30 difference is put inside the lenses and my eye lash rub them all the time and the lenses are stained (dirt) every time... I don´t think this is normal... or is it?

Whata can I do to avoid this?

specs4ever 13 Mar 2005, 05:51

Nikki, the general opinion is that soft contacts increase myopia far more often than not. But hard (boston gas permeable or other rigid gas permeable)lenses do seem to slow the progression. My thoughts would be to wear your old glasses for close work, and your new ones for driving, watching movies, ect. This has been shown to lower your risk of progression for a lot of people. However, there are no guarantees with life.

Niki 13 Mar 2005, 01:59

I think the risks of my becoming more shortsighted are quite high since I use the computer a lot and read a lot too. Is it true that wearing of contact lenses slows down the progression of myopia?

Niki 13 Mar 2005, 01:59

I think the risks of my becoming more shortsighted are quite high since I use the computer a lot and read a lot too. Is it true that wearing contact lenses slows down the progression of myopia?

-14 12 Mar 2005, 18:48


like Mike i'm -14 and manage very well with glasses (don't like contacts) Minification and distortion can be a problem but i've worn strong glasses for so long I don't really notice. Just wear your new glasses and enjoy the great vision you will get with them. Most people really don't notice how strong your glasses are and the ones who do will forget about it in a few days.

Brian-16 12 Mar 2005, 16:04


Thanks for the reply.I am 20/25 in my right eye and just about 20/20 in my left eye.And I know what you mean about the minification.

Mike 12 Mar 2005, 13:26

probably lots of reading

tortoise 12 Mar 2005, 13:06

Mike, I think the standard wisdom is that myopia usually stabilizes in the early 20s but I think that your experience of becoming substantially more nearsighted after that age is becoming more common. Do you think there is anything about your lifestyle, eg. long hours of intense computer use etc., that might have contributed?

Are there any other members of your family whose myopia has continued to progress in a similar way?

Mike 12 Mar 2005, 12:52

Niki, i manage well, although driving at nite is difficult. I don't wish to make you worry, but i was at -5 when i was 21, so you might progress even up to your mid-30's, sorry!

Niki 12 Mar 2005, 11:54

I always thought that - 6 was the limit. When I told some of my friends my new prescription, who are only -2 to - 3, they are shocked at how strong my lenses are. My boyfriend is only - 1 or something like that. He thinks I'm "blind". How do some of you survive with being so shortsighted?

Mike 12 Mar 2005, 11:52

Brian, no i don't minimifaction is a factor i'm only about 20/30

Brian-16 12 Mar 2005, 11:13


I am not too far from your rx -11.50 and -11.25.Do you see 20/20 with glasses?

Mike 12 Mar 2005, 10:50

Nikki, relax don't worry, i'm at -13, -14 so you are hardly "that" nearsighted compared to me

Greg 12 Mar 2005, 10:14


There is much more myopia to be had beyond -6.00. I currently have my left eye at -6.00 and the right -5.25. I can't beleive you went so long wearing your old prescription, I just put on an old pair with that strength and I could not see anything. If you are concerned with thickness just look for a high index lens, but wear your glasses proudly.

Melyssa 12 Mar 2005, 10:12


Sorry to tell you, but there is no limit to how near/short-sighted you can get. I am at -9.00 & -8.25, which at least has been stable since I was about 36. I know I was around -6.00 when I was your age, but I've learned to live with it, difficult as it may sometimes be. But then, 30 pairs of big, bold, beautiful plastic frames help me, too.

Niki 12 Mar 2005, 06:55

I am in my early twenties and I really don't want my eyesight to get any worse.

Isn't - 6 the most shortsighted you can get?

My previous prescription was - 4.00,

- 1.25 for my right eye and - 3.50, - 0.75 for my left. Obviously my new prescription makes quite a big difference. No more asking my friend for college notes and sitting so close to the computer screen.

Greg 11 Mar 2005, 11:53


I had this happen to me when I got my second prescription at age 18. My first glasses were -1.00 and I held off going to the optometrist for two years. I finally went in and I could not see any letters on the eyechart without correction. I ended up walking out of the office with a prescription for -3.50 right and -3.75 left with some astigmatism. From then I was wearing my new thicker glasses. Some people will notice, but most people will just assume you have just worn contacts and hardly notice a change. Plus I think the world needs another GWG, how old are you, and what was your old prescription.

Niki 11 Mar 2005, 07:46

I recently had my prescription increased. I hadn't had my eyes checked in almost 5 years. I am now -5.75, -2 in my left eye and - 5.00, - 1.75 in my right. I can't wear contacts so will be forced to wear these hideous glasses. I feel so embarassed and still wear my old prescription at work as I don't want my colleagues knowing how shortsighted I am. While my boyrfried finds me very sexy, I'm worried about going out in public with my new glasses. Has anyone had the same experience?

Please help!

Sally 24 Feb 2005, 21:22

Jake, try posting question on You will definitely get a post within a few hours!!!

Jake 22 Feb 2005, 08:22

Does anyone know what brand of lenses Costco carries - as well as the brand of A/R Coating? I'm looking at the mid-hi-index range (-5.00 prescription).

K 20 Feb 2005, 00:19

I bought some glasses from Lenscrafters, about 2 weeks ago and they just don't work for me. (Everything's fine, technically. I found an almost identical pair at a mom and pop's shop for about 1/2 of the price.) In general, how hassle-free is their "30-day - No ifs, ands, or buts!" return policy?

Shoe 11 Feb 2005, 14:10

I wear Acuvue2 contacts with 8.7 BC. I previously used Acuvue with 8.8 BC. Does the Base Curve really make a difference in your prescription or does it deal more with comfort? I have noticed that various manufacturers and models are sold with very different numbers. In other words, can you convert the BC number to a different brand of contacts?

Tony 31 Jan 2005, 21:07

Correction to my last thread. The DIA is 14.8, not 14.5 as previously stated.


Tony 31 Jan 2005, 21:06

My CSI Daily Wear Clear contact lenses have been discontinued by CIBA (Wesley-Jessen). I have the same prescription in both eyes, BC 8.9, DIA 14.5 and PWR -7.5. No other contact lens gives me the great visual acuity that I get from this lens. Does anyone know if some contact lens seller has a stockpile of my prescription? I get comfort from other lenses and perfect distance, but my middle distance and reading is not as nearly sharp with other contact lenses. Any suggestions? Thanks very much.

Tony 31 Jan 2005, 21:05

My CSI Daily Wear Clear contact lenses have been discontinued by CIBA (Wesley-Jessen). I have the same prescription in both eyes, BC 8.9, DIA 14.5 and PWR -7.5. No other contact lens gives me the great visual acuity that I get from this lens. Does anyone know if some contact lens seller has a stockpile of my prescription? I get comfort from other lenses and perfect distance, but my middle distance and reading is not as nearly sharp with other contact lenses. Any suggestions? Thanks very much.

DWV 23 Jan 2005, 02:15

I got a pair of glasses at Costco; nothing wrong with the quality. The only drawback was a limited frame selection.

Most opticians should be happy to sell you a frame without lenses; they'll make a massive profit on the frame without the hassles of fitting lenses.

It's also worth checking around; don't overlook the "mom and pop" independent opticians in the strip malls. Occasionally you'll find a place with a great frame selection and fair prices. I bought my latest glasses from a place that had the frames priced LOWER than any online retailer was selling them for.

Mandy 19 Jan 2005, 10:24

Jules- My husband and I have ordered from costco many times and NEVER had a problem with their product (unlike some other places). They have the best prices and have strict qualtiy control. The only downside is that they take 1+ weeks to get them back. But for those who can wait, the savings is well worth it. For one example they had a frame at Lenscrafters that was $120.00 plus another 100+ for the polycarbonate lenses... so ~250 for the whole thing (luckily I caught them on one of their $99 dollar sales). But then went to Costco and found the exact same frame a few months later for ~50-60 dollars with lenses for 40.

I would definatly tell you to give Costco a try. They even managed to get my friends astigmatism plus 3 diopter prisim lenses right on.

Dr.S. 19 Jan 2005, 05:13

The website is a useful place to see if a particular frame model is still current, or to compare styles from various manufacturers.

Matthew 19 Jan 2005, 05:06

I've read before that Costco is one of the more reasonable physical stores (not online) to get glasses/lenses. I would expect their quality to be fine (though it's hard to know for sure until you try).

I would think a place like Lenscrafters would sell just the frames without lenses. I guess the thing to do, though, is to shop for frames first, write down the information identifying the frame, and then ask them if you can buy the frame alone. If they say no, you thank them for doing you a favor, and go find them cheaper somewhere else, which should be possible in many cases. Some online stores have an enormous selection of frames (, for example, though they aren't particularly cheap).

daffy 18 Jan 2005, 16:32

Jules - I always shop around and end up buying frames from one place and get the lenses fitted in another to reduce my cost. There is an element of 'risk'. The store that ends up fitting the lenses always say that they are not responsible if the frames get damaged - but that has never happened (and seriously, to damage a pair by fitting lenses would have to be blatently intetional anyway).

Another cost cutting method i've done is (which is not always sucessful) is to shop around for the frames i like, get the details (manufacturer, model, style colour , size - usually written on the frame arm) and shop on the web, even ebay.

Jules 18 Jan 2005, 12:38

Ok, I see that you can get plano lenses. Is the cost of plano lenses comparable to that of normal lenses - or is it much less?

Jules 18 Jan 2005, 12:25


Is it possible to simply purchase frames from an optical shop, like Lenscrafters? For some reason, I thought you couldn't purchase frames without the lenses.

I went to Costco, yesterday, to grab a few things and stopped by the optical shop. Turns out, I can get the same 1.67 lenses + AR coating for $80!!! Unless there is something horribly wrong with Costco, I think I am going to take my old frames there and have replacement lenses put into them, for the time being. If I am able to find some other frames (like the ones I had at Lenscrafters), I'll take them there, as well. I was able to get a full refund for the glasses, from Lenscrafters, so no harm there. :-)

Matthew 18 Jan 2005, 06:23

Jules - one thing you could do in the future is pick out your frames at a place like lenscrafters and send them to an online place to have lenses put in them. Some of the online places (, are, I think, pretty willing to do lenses in frames you send. The deal isn't as good as if you get complete glasses from them, but it's still a good improvement.

Kathy 17 Jan 2005, 14:09

Hi Jules, with your prescription and the hi-index lenses, and a/r coating, I think that you might have paid a little too much for them. The one good thing about Lenscrafters is that they will make your glasses in an hour, but they are pricey, unless you use the AAA discount which will take 25 percent off the final bill. If you want a little consolation, my last pair was a 3 piece drill mount rimless frame by chanel with a/r coating on the lenses. The final price was about $500, but it was worth every cent because it is the lightest pair of glasses that I have ever worn. I got those at a eyeglass boutique on the Vegas strip. I noticed that it is cheaper to get your glasses on the net, but the only problem is that you won't know if the frame fits your face or not. Anyway, at least you got a 30 day guarantee with them, hopefully, you like your glasses.

Jules 17 Jan 2005, 13:43

Central NC - so anything between Winston-Salem and Raleigh is fair game - or even Charlotte!

 17 Jan 2005, 10:50

jules - where are you located?

Jules 17 Jan 2005, 08:43

My apologies for cross-posting (I posted this question in the Acuity and Prescription II forum, with no response, yet.)

Today, I bought some glasses at Lenscrafters (some really funky tianium half-rimless ones - quite cool!). My prescription is -5.25 in both eyes. I was floored when my final bill was $407.00 (that included a $100 discount, from insurance). The frames were $170, 1.67 lenses $260, and AR coating was $70. Granted, they have the 30-day return policy. However, I feel like I could do better, price-wise. Searching through various websites, it seems that the same lenses and AR coating aren't NEARLY as much. What do you guys think? Are there any other optical shops you would recommend - or should I expect to pay that much for those type of lenses and coating, without ordering online?

neenee 14 Jan 2005, 11:20

daffy-----sorry i forgot to actually address that last posting to you. it was to answer your question. thank you again.

and again---to all who reponded to my question---- thank you again.

neenee 14 Jan 2005, 11:15

i 've been feeling dizzy/lightheaded on and off since i had the prism put in my glasses. i didn't know if it could possibly be the glasses or if it was an entirely different problem.

thank you all for your input. i do appreciate it.

Wayne_D 13 Jan 2005, 23:02


The index of refraction for CR-39 is 1.498

Mark 13 Jan 2005, 20:50

Katy - CR-39 index: I'm not sure, but 1.49 sounds believable.

 13 Jan 2005, 17:39

daffy 13 Jan 2005, 15:43

neenee - i had the same feeling at first as well. If i remember correctly, Larissa (a poster on here that hasn't been on here for a while) also had the same feeling at the beginning. I think (no expertise here) that it waries from person to person. Why do you ask?

Clare 13 Jan 2005, 13:17

Forgot - lens material, polycarbonate (1.56?)

Clare 13 Jan 2005, 13:16

Katy - practical exercise: frame size 46cm, PD 61, edge thickness of -2.75 = 3mm

Katy 13 Jan 2005, 07:11

Mark - thanks. The lens size would be 46mm, in plastic, pd = 63. I found a couple of sites with a formula but wasn't sure what the refractive index of standard plastic is - is it 1.49?

-14 13 Jan 2005, 06:52


Yes i do have 20/20 with them altho they are single vision and i have a +3 add so reading can be a problem. I have to resort to the old "slide them down my nose" trick.


I have prisms (only 2BO) and had no problems when i first started wearing them.

Brian- 13 Jan 2005, 06:25

-14..Yes,they are amazingly thin.I saw the picture and could not beleive how thin they are.Do you have 20/20 vision with them?

Brian-16 13 Jan 2005, 06:24

neenee-I have prism and have had no trouble.They are 5.0 base out.

neenee 13 Jan 2005, 06:16

has anyone else felt dizzy/lightheaded when they first started wearing prism glasses???

Mark 13 Jan 2005, 06:15

Katy -

There are lens thickness calculators on the internet somewhere (and listed in some old posts on this site; have a look around...searching for the word "calculatlor" ought to help).

When you say "average" size, do you mean average for a women, today? (About 45-48mm eyesize, or so)

What kind of material? (regular plastic <aka CR-39>, polycarbonate, etc?)

What's the pupilary distance?

Lots of questions. But I'd say for standard "unisex" glasses (let's say 48-49mm eyesize), something like 4mm for regular plastic and 3mm for polycarbonate (less for higher index). Maybe a bit less than this. Definitely less if the glasses are on the smaller side.

Related note: For very large glasses (by today's standards; average in the early 90's) in regular plastic, -4s might be as thick as 7mm or so.

Katy 13 Jan 2005, 01:17

Does anyone know the formula to work out lens edge thickness from rx and lens size? Or could someone give me a rough idea how thick -4s would be in average sized rectangular frames? Thanks :-)

-14 12 Jan 2005, 17:10


When i'm wearing them the smaller bowls are not noticeable at all although in the right light because the fronts are plano you can tell they are myos. They are only 3mm thick so from the side they are thinner than a friend's -2s.

Brian-16 12 Jan 2005, 14:43

-14 O.K. I get the picture.So I assume than the 28mm bowls would not be quite as noticeable.He did not give me his entire rx,but he is around -16d

-14 12 Jan 2005, 14:26


Sorry that should read 25mm bowls.

-14 12 Jan 2005, 14:25

Brian 16-

You can check out my myos at:;act=ST;f=4;t=22

The bowls are 28mm. BTW what is your cousin's RX?

Brian-16 12 Jan 2005, 13:51

Curt or anyone on ES.My cousin who lives 3,000 miles from me just got myo-discs.Have not seen the specs but he tells me they have a 25mm bowl whatever that is.He further said he could have had a 38 mm bowl.Can you explain this or direct me to a site where I can see this? Thanks

 11 Jan 2005, 09:20

22: you can go between glasses an contacts no problem, unless you have a really really strong prescription, where you will notice the magnification or minification more with glasses, or if you have prism correction, in which case, you must always wear glasses.

Curt 11 Jan 2005, 08:45

Brian: Not really that cryptic. There are only 4 orientations for prism corrections:

base in = b.i.

base out = b.o.

base down = b.d.

base up = b.u.

They can be combined, but those are basically it!

22 10 Jan 2005, 19:22

Thanks for answering my previous question.... another quick question...If i get contacts, and wear it for a long time, will it be hard for me to wear glasses. and vice versa? Thanks

neenee 10 Jan 2005, 15:45

brian ---yeah i think that's what the girl said when i asked her for the prescription--"base up"-- but she told me to write it as b.u.

Brian-16 10 Jan 2005, 15:13

Curt-Beats me! Rather criptic way of putting it.

Curt 10 Jan 2005, 13:38

Brian-16: Wouldn't bu be "base up"???

Brian-16 10 Jan 2005, 13:03

neenee-Yes,sounds to me like 1 base in on the right eye.

neenee 10 Jan 2005, 12:38

brian---is this the right info.?

1 bu in R

Brian-16 10 Jan 2005, 05:23

neenee-Well yes thats the rx but does not have the prism rx with it.

neenee 09 Jan 2005, 17:14

hi brian, i'm not sure. this is what i think i remember it being.



does this make any sense????

LikeGlass 06 Jan 2005, 18:50

Short answer, no. The numbers are different due to location (on the eye.) also, if your Rx has an axis (astig) things get evenmore tricky.

22 06 Jan 2005, 18:00

Question - I have eye glasses and want contacts...can the can the same prescription be used to get contacts? thanks.

Brian-16 30 Dec 2004, 08:02

neenee-Do you know what your rx is and type of prisms?

neenee 29 Dec 2004, 14:24

i got prisms in my glasses not too long ago. soon after this, i started feeling mildly lightheaded/dizzy alot of the time during the day, sometimes it would be worse than others and sometimes i'd feel ok. any thoughts???

Mike 26 Dec 2004, 18:20

Mine are XR Toric (B&L) but not sure how you will handle your axis, it becomes difficult without a professional Rx

LikeGlass 23 Dec 2004, 14:00

Going to be hard to get that Astig in a contact on line. Not even sure how to deal with the rotation on a contact lens.

Anne 23 Dec 2004, 12:33

My prescription is

R sphere +5.50 cyl-2.50 axis 172

L sphere +5.00 cyl -2.75 axis 3

What power contact lens should i order as i want to order them off the net


-oo- 20 Dec 2004, 18:36

visit boy, please don't fool with prism. See JB & Daffys posts below and elsewhere on this site.

Prism is a much more complex and serious thing than simple sphere and even cylindar

Brian-16 20 Dec 2004, 17:39

VisitBoy-Yes my prism rx has increased slowly from 2 to 5d over 18 months.But then so has my myopia.

Myopeman 20 Dec 2004, 15:46

Visitboy, I wouldn't recommend experimenting with prisms. It's one thing to become more myopic, but messing with the way your eyes align sounds dodgy to me. You can make your specs thicker simply by changing the plastic they are made out of - they'll look great!

VisitBoy 20 Dec 2004, 13:14

Brian: Thanks. Currently -4.00. How long have you had prism correction, and has there been a progression?

Brian 20 Dec 2004, 06:39

Visit-Boy-I have 5.0d base out prisms and the edges by the temples are thicker.If you get base in prisms the edges by your nose will be thicker.I can not see anything with out my specs,and yes my eyes do turn in without prisms.If you wish to experiment try base out prisms first.What is your current rx?

VisitBoy 19 Dec 2004, 15:14

Could anyone advise me please: If I start wearning prism and become dependent on it, will it show when I take my glasses off? i.e. Will my eyes learn to diverge or converge?

I'd like my lenses to look a bit thicker I guess, but not all on the outside if that leaves them really thin on the inside.

JB 30 Nov 2004, 23:20


Why would i want to " have you on " ?

a"bit and dollop" refer to having some, neither being larger or smaller than the other.

My rx is

L - 4.50 - .75 90 2d b/o + 1.00

R - 4.75 - 1.00 140 2d b/o + 1.25

The point i was getting across was nothing to do with my astigmatism, which i grant my explanation may have been wrong / inaccurate, but the requirement for prisms and the way in which they can affect you when used on a regular basis.

I hope this clears up any misunderstandings

Filthy McNasty 30 Nov 2004, 06:58

In common parlance, a "dollop" would be bigger than a "bit", and I think that's how you've used it in your post below. If so, please explain how you can have different amounts of cylinder and astigmatism (aside from allowances for vertex distance), since the former corrects for the latter? Or are you just having us on?

JB 28 Nov 2004, 23:40


I refer you to my post of a few weeks ago, copied here for you.

I was recently prescribed 2d b/o prisms and duly had the prescription made up,i had been suffering double vision on and off for the past few months.

After i collected my new glasses L - 4.50 R - 4.75 with a bit of cylinder and a dollop of astigmatism with a small add, and now prisms, i noticed that the double vision had gone within a few days but also whenever i removed my glasses i started to get a headache within about 30 minutes.This would not normally be a problem as i wear my glasses all the time,however, i do occasionally have to wear saftey glasses in my work, these have my old prescription,and i am finding within a couple of hours i get a killer headache, must be due to lack of prism correction which i have so quickly become dependant upon.

I have now taken my safety glasses in to have the new lenses fitted, this should cure the problem but to emphasize Daffy's point, do'nt mess with prisms as they do affect your eyes severely and quickly, i was astounded as i have always been able to function without my glasses for a few hours or around the house etc, it now seems i am set to wear them all my waking hours and with no possibility of using contacts again.....Be warned

From my experience and others, such as Zane, you will likely become dependant upon the prisms within a very short space of time.I would suggest you do not go ahead with your idea unless you are prepared to wear glasses all the time and put up with the discomfort if you need to remove them for any length of time during waking hours.

Good luck ,but think long and hard before you go ahead.

Prism-desirer 28 Nov 2004, 21:13

Thanks D-W-V for the photos. I like base-out because of its outer lens thickness, although it would be great to be a higher myope too.

Could anyone else comment on their experiences of whether prism makes your eyes diverge/converge obviously, with glasses or without?

Any comments on combining prism with my current prescription (mid-myopic)? And am I likely to become dependent on the prism?

Thanks all.

+ lover 28 Nov 2004, 18:46

HI I am looking for some advice on how to get prescriptions filled for GOC all of the web sights i have checked want doctor verification and i can't get my hands on a real prescription to use. If anyone knows a good way to get the stuff i need to start GOC i would be greatful

Katy 28 Nov 2004, 15:42

D-W-V - thanks. I can't believe I spelt your name wrong - it is only 3 letters! Those are incredibly thick - 5D non-high index must be unbelievable.

Does anyone know whether people with base out prisms usually get stronger ones after a while or does that happen more with the base in ones? (assuming they needed them in the first place, that is!)

Katy :-)

D-W-V 28 Nov 2004, 14:28


That was 5D in one eye, 6D in the other (the trial set just had one lens in each size of prism, so I couldn't have them both the same). I also tried 9D and 10D (per eye); that was tolerable too.

The trial lenses are pretty small, so I couldn't see my eyes too well in the mirror, but they didn't look obviously crosseyed. I did notice some unusual reflections because of the angles in the prisms.

Here's some glasses with 5D base out prism:

Katy 28 Nov 2004, 04:21

D-V-W - is that 5-6D in each eye or overall? And can you tell that there are prisms in the lenses if you look at them from the front? Do they make your eyes look less straight? Thanks, Katy :-)

D-W-V 27 Nov 2004, 23:57

I tried wearing some prism using trial lenses: 5 or 6 D base out is no problem to see with, and it looks like it would add a hefty amount of thickness to the outside edges of the lenses. With the same amount base-in, I just see double. YMMV. Offer void where prohibited. Not tested on animals.

Brian-16 26 Nov 2004, 10:04

Prism-Desirer-The sponsor here,Optical4less only charges $2 per diopter of prism rx. You will have no problem seeing unless you get base in prisms of high rx.Go with base out first. Base up or down is okay,too.Start low,say around 4.0d.

Singa 26 Nov 2004, 08:37

In Switzerland we have a optical-company

with very good prices. I know that in many shops the prismn have a big additional price, however un this shop the add of prism from 1 to 12 is free included in the price. For example:

1 frame with 2 lenses antireflexing etc.

unti +/- 6.00 sph. and +/- 2.00 cyl. and until 12 prismn is about 120 USD only. and with progressive lens the same about USD 350.--

Prism-desirer 24 Nov 2004, 14:09

Thanks Curt.

Any idea how much prism would be a good place to start? I guess base-out would make my eyes diverge for a while, so I wonder how long it would take to be able to see with it.

DNBursky 22 Nov 2004, 20:14


How old were you when you tried on your friend's glasses and wore them? How old are you now? Just curious.


Curt 22 Nov 2004, 13:04

Prism-desirer: Only if the other person's glasses are sufficiently strong and their PD is signficanlty different from yours. Assume that a person is wearing -5.0 D lenses in each eye, and that their PD is 58. If you wear those glasses and your PD is acutally 60, you are only inducing 0.2D of prism, not enough to really notice.

I don't think most folks glasses are strong enough to induce a significant amount of prism (Remember the example used earlier: a -10D lens off by 1mm gives 1D of prism). How many folks wearing >10D lenses do you know. And if the PD is really, really different, the glasses probably will not fit your face (too narrow or too wide).

Prism-desirer  22 Nov 2004, 12:56

Thanks Brian-16. Sounds like I'd want base out.

Would someone explain how, if prism is the same as adjusting the pupillary distance and is also so "addictive" (makes people reliant), us glasses lovers don't become more easily stuck with lenses we don't need when we wear other people's glasses for a while? Isn't it likely that they'd induce some prism?

I want to be dependent on my glasses, although I know some of you who are might not understand this. :)

ant 22 Nov 2004, 04:00

I believe Fresnel prisms are stick-on plastic prisms which are stuck on to your existing lenses. It enables a stronger prism without adding very much to the thickness of the existing lens. I had them as a temporary measure when having treatment for my strabismus.

I also know that once your eyes have got used to prisms it's almost impossible to cope with out them. Mine are now 10 base out with 5 base down in one eye and 4 base up in the other.

mattp 21 Nov 2004, 12:13


I didn't really state the case with my contacts RX very clearly. Years ago, I had monovision correction with my contacts--left eye reading RX, right eye distance RX. I had to give that up when the reading RX got to 2 add--brain couldn't handle that big a discrepancy between vision in the two eyes.

This situation now is not monovision in that sense. When I went for contacts for sports, I asked the doc how he would handle the need for prism that I have now. He said he would undercorrect the distance vision in my left eye, the one that turns out, so I wouldn't exxperience prism withdrawal (dizziness and double vision. But the contacts RX is not really monovision because the RX in my left eye is still so strong I cannot see to read without reading glasses (with the prism). Yes, I can see a bit better up close with the left eye contact lens--I can read the time on my watch, fo rexample, which I can't do with the right contact.

I hope this clarifies the situation a bit!--Matt

Brian-16 21 Nov 2004, 10:51

Prism-desirer-Perhaps you have seen a blank rx on-line somewhere-so under prism insert a number such as 4.0 or 6.0 or something like that.If you want the glasses to be thicker at the temples (outside),then its base out or just put "out" under the base section of the rx.For nearsightedness, its a minus figure.Example-

Spherical cyl axis prism base

-1.00 -.25 165 4.0 out

If you want the lenses thicker near the nose,then it is base "in"...

o.d. is right eye, o.s. is left eye

Hope this helps...

 21 Nov 2004, 10:32

I’ve told you I wear prim 15º base externa (base out) with lenses over +24,00 up with +4,00 bottom. I have eyes that crosses much more without them. My oph says I have a thing called bilateral type 1 Duane Syndrome I think, due to a Infantile Congenital Esotropia? severe accommodative esotropia so, the lenses help reduce the nystagmus to an almost null point, I can see better with them, thought I must say, my glasses looks so weird and thick.

As I said in “Strong Glasses”, with the base out prism lenses the nystagmus I've almost disappear due to accommodation my eyes get when looking straight. Now... when I try to move my eyes around then nystagmus are shown again. My doctor says I will have to get something called “prisma Fresnell with 25 graus de base”, they are stronger. Without my glasses, my eyes crosses very much and the nystagmus are visible to the point I can't find any comfort position of my head and soon I have severe head ache.

Does anybody knows what “Prisma Fresnell with 25 graus de base”, or “Fresnell Prisms is or what for is it?”

Yet I began eyes treatment by seven, by accident I must say, I think I have had eyes problems as far as I remember, back to days I was wee kid, ‘cause I was very clumsy, always stumbling into things, mistaking stairs, always having sore foot thumbs, being called Mr Magoo, etc…

Back in those days, I really didn’t know I was different, I was in an orphanage yet, and there were so many kids.

Pardon my English.

Prism-desirer 21 Nov 2004, 10:15

I'd love to need glasses to see clearly, and I'm just a little bit myopic. How would I write my prescription to get prisms made up, preferably for thicker minus lenses?

Clare 21 Nov 2004, 07:02

Mattp - Apologies in advance if I've got the wrong end of the stick but you say your left eye is undercorrected for distance (with contacts) and the eye dr said this has the same effect as a prism correction. That sounds like the same effect as mono vision contacts, does it mean that people who do that, and I've a friend who does, are actually also experiencing prism correction even if they don't need it?

mattp 21 Nov 2004, 05:37

Just adding my experience to the prism discussion. About a year ago, my left eye began having trouble focusing when reading, and I was prescribed 3d base-in in my left lens to keep my eye from wandering out. Just recently, the RX changed to 2d base in in both lenses to keep my eyes pulling together instead of turning out with double vision. By the way my RX is about -4.50 with 2.50 add in trifocals.

Like you folks, I can no longer go without my glasses without double vision and headache almost immediately. I do have contacts for sports, and I can wear them even without prism correction. The right eye is RX for distance; the left eye not strong enough for full distance correction. Eye doc says this does the same thing as prism correction. However, I cannot use over the counter readers--double vision and headache when reading. I have readers with prism correction for reading with contacts in.

 21 Nov 2004, 05:02

I've had prisms ,4d base out, in my glasses for 20 years. Like JB i very soon found i could not go without specs for more than an hour or so without either getting severe headache or finding my eys crossed and double vision set in.

leelee 19 Nov 2004, 21:04

Base-in Prisms move the image slightly outward so your eyes don't have to turn in so much. I also have some exophoria (which is term for when your eyes drift out if there is nothing to see - they discover it by covering one eye and then taking the cover away to see if the eye moves, if it does, they use this stick with stack of prisms to see which one equalizes the drift.

Since this happens to me, I've done lots of reading on the topic. I found that it is the opinion of the optometric community that prisms for exo-deviations are generally not that helpful - that you just tend to continue to need more and more, but that vision therapy is actually quite successful for this. What vision therapy does for this is help you learn how to relax your visual system and provides exercises to build up your convergence reserve and it also works to teach your brain to focus on different distances for varying convergences. At my peak, I was able to look at stereo pictures without the device. Apparently, there is also some sort of relationship between the position of your eyes (converged or diverged) and the amount the brain tells your eyeballs to turn the focus knob. I don't quite understand it, but I think it might be that if your eyes are used to being 2 dioptres focused when looking at infinity (eyes are parallel) then when you put on +2 glasses, your brain still says (the eyeballs are parallel, I better turn the focus knob to +2. when it sees blur, it says, uh-oh, blur - that means I need to focus more, so it turns the knob to +2.25, which does not help at all! I might be talking thru my hat here, but this is what I have gleaned from lots of reading (much of it ill converged and blurry!)

I went thru vision therapy about 10 years ago, and I probably need an update now. As I recall, my reading comprehension was very greatly improved, tho it did not help me avoid glasses, it did help me avoid prisms.

Brian 19 Nov 2004, 17:52

What exactly is it with prism lenses that makes them mess up your vision so much as opposed to other lenses? I've heard many stories on this board about people getting prism glasses or trying prism glasses and really messing up their vision.. I've been told I might have to get them in a few years due to exotropia I believe the term is called.. My eyes I guess sit slight outward and from time to time I have some focusing problems but nothing major but was told if the problems get worse base-in prisms would correct my problem.. Obviously from hearing the stories on the board about not being able to wear contacts, double vision getting worse, etc.. I'm not looking forward to it, if it comes to needing them.. At my last exam I was told that a slight prism correction might help, but after discussing my options with the doctor, i've put it off and really haven't been experierencing any additional problems.. Has anyone seen any posting from Larissa that posed here a while back, and how her friend ended up getting a prism correction after trying her glasses? Have a good evening everyone!

JB 19 Nov 2004, 08:33

Zane, Seems like my experiance is similar to yours, only i was prescribed prisms to sort out double vision.

I will now be wearing my glasses all my waking hours and will not be using contacts, oh well, that's life

Julian 19 Nov 2004, 08:19

Yes, I thought so too.

tortoise 19 Nov 2004, 07:59

Val, your English is excellent! Good post.

Val 19 Nov 2004, 07:20

I am not a specialist, but I think that every action has a reaction. Sometimes it's hard to find a reaction that is strong enough to counteract, but you can find it eventually.

When the eyes get crossed or diverge the problem is all in the muscles that sustain and move the eyes. To correct the problem the eye-doctor has 3 possibilities: surgery, recommend physical exercises, or to prescribe lenses with prisms.

I don't know how strong defect can be corrected with physical exercises, but some of them can be corrected. I am sure about that. About 10 years ago (I'm 36 now) one eye doctor said, after putting me on some device, the my eyes tend to converge and he taught me some exercises to do at home for at least one month. Well, I can tell you that even now I do exercises from time to time and it's very good.

Maybe, for people who are already adjusted to prism lenses it will be very hard, or impossible to find a set of exercises to correct their problem, but it worth a try.

Bye, for now; it's hard for me to write in english. It's taking me to much time to form a sentence.

Zane 19 Nov 2004, 05:41


I will be quick now as I am getting boring.

I don't know what the rx of those glasses was, I only know that I wore them for another year and finally went to have my eyes tested. The eye doc assumed I'd worn glasses for a long time and I was too embarrassed to do anything but agree with him.

He said my eyes had improved????? and prescribed me +2.75 2d b/o both eyes the same.

So, I wear them all the time and really suffer if I don't. I look hideous without them anyway as my eyes cross within a few minutes.

There's no going back for me now, I am paying the price for my stupidity, I really don't want anyone to make the same mistake. I am really sorry for all the people out there who genuinely need prism correction through no fault of their own.

Zane 19 Nov 2004, 05:30

It was a couple of years ago. I started wearing a friends old glasses, I told him I wished I had glasses and he said he had worn them since he was 3. He said he had loads of old pairs and I could have a pair if I wanted. I chose a pair I thought suited me. Even though they were far too strong for me and my vision was very blurred with them, I loved how they felt on my face, and gradually I got used to them. I wore them as much as I could and eventually ended up wearing them constantly. As I was living away from home, noone knew me so it was easy to wear them all the time.

At the time I didn't know what a prism correction was, all I knew was that these glasses were great.My friend never mentioned anything about a prism either.

I wore them for about 3 months, only taking them off to sleep and shower.

When summer came, the novelty had worn off. They kept sliding down my nose, I wanted to wear my light weight sunglasses instead of the bulky glasses.

That is when I realised I had a problem.

When I took them off, I waited for my vision to return. It never did. I had constant double vision and the worst headaches.

The longest I could leave them off was an hour and that was too long, it was a relief to get them back on my face.

Zane 19 Nov 2004, 05:10

JB 18 Nov 2004, 23:18

I fully understand daffy's comments.

I was recently prescribed 2d b/o prisms and duly had the prescription made up,i had been suffering double vision on and off for the past few months.

After i collected my new glasses L - 4.50 R - 4.75 with a bit of cylinder and a dollop of astigmatism with a small add, and now prisms, i noticed that the double vision had gone within a few days but also whenever i removed my glasses i started to get a headache within about 30 minutes.This would not normally be a problem as i wear my glasses all the time,however, i do occasionally have to wear saftey glasses in my work, these have my old prescription,and i am finding within a couple of hours i get a killer headache, must be due to lack of prism correction which i have so quickly become dependant upon.

I have now taken my safety glasses in to have the new lenses fitted, this should cure the problem but to emphasize Daffy's point, do'nt mess with prisms as they do affect your eyes severely and quickly, i was astounded as i have always been able to function without my glasses for a few hours or around the house etc, it now seems i am set to wear them all my waking hours and with no possibility of using contacts again.....Be warned

 18 Nov 2004, 16:05

Also my glasses stinks, so bloody thick.

I am sorry.

 18 Nov 2004, 16:02

"Zane-I wear base out prisms and can not do without them as my eyes move in and get cross-eyed."

I wear 15º base externa with lenses over +20,00 adding +4,00 bottom. I have eyes that crosses severely without them. But doctor says the lenses helps me seeing better with them, thought I see no difference, I must say. hahaha...

Also I still can not adjust to them. So f@#$%ing pisses me off.

daffy 18 Nov 2004, 15:59

'twas me...i did it. I messed with prisms and regret it, and don't recommend toying with it. I used the opposite...base in. I was sort of forced to wear them because i got an eye infection at the time and couldn't wear the contacts, but at my rx, i needed glasses to see and all i had were the glasses that were made up with the prisms. I wore those for about a month, and got used to them. Now, for some reason i don't know why, i was never able to go back. I tried for weeks to go with contacts, but the headaches were persistant until i put the glasses back on. Now, the prisms are prescribed. My most recent Rx given (but not filled yet) is (same on both R & L) Sph-5.5 Cyl-1.0 Ax (R, 180: L,20), Pr 3.5BIn, Add +1.75.

I don't know why, but the lenses initially made my eyes turn out, but eventually my eyes accustomed and ended up straight with the glasses on. Now when i take the glasses off, they are slightly crossed. I confirmed this behaviour with pictures.

Matthew 18 Nov 2004, 13:43

squinty - for what it's worth, I'd think it would be pretty easy to get used to base-out prisms, which would basically make the eyes cross ('converge') more to see a given object. This is the kind of adjustment the eyes do all the time. Getting used to base-out prisms would obviously be harder, since the eyes are not used to ever *diverging*. The question remains: once you adapt in one direction, is it harder to adapt in the other direction?

Some quick experiments I've done with base-up/down suggest it's pretty easy to adjust to up/down prism in either direction.

Matthew 18 Nov 2004, 13:39

Squinty -- I've wondered about this too. I would suspect that *most* people's eyes can adjust pretty well to almost anything. But it's possible that the eyes tend to make the adjustment in one direction more readily than in the opposite direction. That's why I was wondering what Rx Zane used.

Brian-16 18 Nov 2004, 11:33

Zane-I wear base out prisms and can not do without them as my eyes move in and get cross-eyed.Wondering what your rx was and the strength of the prisms...

squinty 18 Nov 2004, 06:37

If you can become used to prisms so quickly, why cant you become un-used to them? I mean if you really did not need them in the first place?

I wonder if you could just take a week and stiff it out - sort of like going cold turkey or doing a fast. I expect you would be dizzy and nauseated for much of it, but then perhaps you could get back the proper alignment.

I'm not making a challenge, I've just always wondered about this. There was another guy here who did this to himself too.

Matthew 18 Nov 2004, 06:20

Zane - Did you use base-in, base-out, base up/down, or some combination? How strong? How long did you wear them before you found you couldn't do without them?

Zane 18 Nov 2004, 04:46

Please do not mess around with prisms.

I ruined my pefectly good eyesight by wearing glasses with prisms.

I now cannot do without them and am crosseyed.

I have tried various eye training methods but none have worked.

Try GOC etc. but stay clear of prisms if you don't need them.

 17 Nov 2004, 16:52

decentering is NOT the recommended method, but it is widely used. If the Rx is high, then other problems are evident...can't remember the term, but the visual distortion away from the center of the lens increases.

 11 Nov 2004, 21:44

Decentering is NOT the way to go for prism in a normal everyday rx.

If you are trying to get the maximim prism obtainable over a ground in prism, then it is ok.

This is into the fetish zone.

Prism 11 Nov 2004, 15:29

It's called "Prentice's Rule"

For example, a -10.00 lens, de-centered 1mm, will give 1D of prism. De-centered 10mm will give 10D prism.

You can change your PD on your prescription to incorporate (effectively) prism in your glasses. If you have a -10.00 in both eyes. Your P.D. = 60mm. Change your P.D. to 70mm and you get 5D Base In prism in each eye!

Matthew 11 Nov 2004, 12:40

Does someone have a formula for the amount of decentering that's equivalent to a certain number of prism-diopters (for a given Rx)? I thought I saw something like that posted at some point, but I couldn't find it.


Julian 08 Nov 2004, 05:47

Yes, interesting article. BUT what he says in the text about where the cylider correction is is the opposite of what his diagrams say. I always thought the diagram was the right way of expressing it - it certainly makes more sense. I hope I've put that clearly!

Love and kisses, Jules.

Lazysiow 08 Nov 2004, 01:51

Finally found a definitive document about astigmatism and how the lenses work to correct it. Should finally put an end to the "what does cylinder do?" and "where do I need it?" questions

 25 Oct 2004, 17:24

Hey Circlemaster !!! Why did you end your action early? Was my bid not high enough?

PENELOPE 25 Oct 2004, 13:15

Here is a site which, if nothing else,will give all of us some tiny education respecting the industry by the MASTER :

 25 Oct 2004, 12:40

Can anyone tell me the process I would use to simulate highly myopic lens using Adobe Photoshop? I have tried but with little success. I have seen pictures online with it done. What tools do you use?

circlemaster0 07 Oct 2004, 10:37

just put a pair of -20.00 glasses on ebay . search for "myopic" to find them. seller name "circlemaster0"


Tod 02 Oct 2004, 14:45

Tod 02 Oct 2004, 14:41

circlemaster0 29 Sep 2004, 09:38

Just put a pair of brand new +20.00

hyperope glasses on ebay.

Ignorant 28 Sep 2004, 06:29

A stupid question, I know, but what are biconcave lenses? I have come across the term often enough on this site, and while I can infer they are for strong prescriptions, I am unsure as to what they ARE! And how are they dif