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Astigmatism

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punktlos 27 Feb 2017, 14:33

I've had the eye exam today and don't really know what to make of it.

First I did the automatic test again, after which the optometrist told me that the results speak for wearing glasses permanently because of -1 diopter of asigmatism and -1.5 at night vision. (I didn't know that was a thing, different diopter values for day and night...)

Then they did what you called the "subjective part" of the exam. And to be honest I didn't notice the difference in most of the lenses she put into the test frame. I could read the bottom line with any constellation, it wasn't very small anyway.

I ended up with sph +0.5 cyl -1.0 7 for my right eye and sph +0.25 cyl -0.5 174 for my left eye. However, comparing my vision with the test frame and without it I didn't see a real difference. I told my optometrist so, and she said that probably my better eye compensates a bit and that glasses didn't make sense as long as I don't experience head aches.

I'm a bit puzzled now. Can I drive at night like this?


punktlos 21 Feb 2017, 10:20

I'm living in the EU and study humanities. I'll let you know "numbers" when I get the exam next Monday.


Cactus Jack 21 Feb 2017, 08:53

punktlos.

I suspect, if you get an eye exam, the prescription will not be very strong. Higher level school work typically involves a very high visual workload, but if you are fortunate enough to have good vision, your eyes and brain can easily deal with it without needing anything, glasses for example, to help. With a few exceptions, such as driving, wearing vision correction is optional. There is no such thing as Vision Police and you don't need the permission from anyone else to wear or not wear vision correction no matter what your vision is.

The human body is amazingly adaptable to its environment. Even if you have perfect vision and excellent health, an eye exam is a good idea. The eyes are windows into the body. There are a number of "silent" health conditions that are first detected on an eye exam. Most of these conditions are easily managed if caught early, but can cause serious problems later in life. Diabetes, High Blood Pressure and Glaucoma are good examples.

It could be that the Optician just wants to sell some glasses. Unfortunately, that happens, but not very often. If it happens, it typically happens in large optical chain stores where there is considerable pressure to "upsell" nice-to-have additions such as Anti-Reflective Coatings, ultra thin lenses or designer frames. Independent Eye Care Professionals (ECPs) rarely do that. In most countries, if you pay for an eye exam, it is required that you be given your prescription. It is NOT necessary that you order glasses from the examiner. You can order glasses from any optical dispenser you wish.

I really need numbers to offer suggestions, but I can offer one suggestion now. If you get an eye exam and you get glasses, it is often best to wear them full time for about 2 weeks before making a decision about when to wear them. That gives your brain time to become accustomed to having good images to work with.

May I ask where you live and your field of study?

C.


punktlos 21 Feb 2017, 04:13

That piece about eye exams was an interesting read, thank you. I'm not sure I comprehended every detail, though. Physics has never been my strong point back in school.

I'm not quite sure, however, if I'm really in for a pleasant surprise. If I understood you correctly, once my brain gets accustomed to this new kind of vision, it will no longer work as hard for me as it used to, leaving me with bad vision.

You know, I don't really see a big advantage in this, as I'm not experiencing tired eyes or headaches (I don't even know how they feel, fortunately never had them in my life...).

I'm 20 and a student, by the way.


Cactus Jack 20 Feb 2017, 15:24

punktlos,

Not really very high, but I think you are in for a pleasant surprise.

Vision actually occurs in the brain. Your eyes are merely biological cameras. Depending on age, most people can correct a little farsightedness (Hyperopia), internally, using their auto-focus system.

However, Astigmatism has to be corrected externally. Astigmatism is usually caused by uneven curvature of the front surface of the Cornea and it affects vision at all distances. Your eyes have been delivering distorted images to your brain.

I mentioned that vision actually occurs in the brain and the brain has amazing ability to correct some distorted images, IF it knows what something is supposed to look like. The snag is that it takes effort and energy. The brain even has the ability to generate images WITHOUT input from your eyes. Ever had a dream?

If you get glasses, which correct the images optically, it will take a few days until your brain learns that it no longer has to work so hard.

Think of glasses as simply tools to make it easier for you to see well. Really, they aren't any different than other tools you use every day.

You might consider reading "How to Study for an Eye Exam". I think I posted it recently on the Vision thread. If you can 't find it, let me know and I will repost it.

May I ask your age and occupation?

C.


punktlos 20 Feb 2017, 11:31

Hey there!

Today I spontaneously decided to take a computer eye test at my local optician. I didn't (and don't) feel like I had bad vision, but figured it wouldn't hurt to check anyway as I didn't have them tested since I had a little accident with a sled back when I was 8. I'm going off at a tangent here...

I was shown a red balloon getting blurry and before i knew what was happening they told me to come back later the week for a proper eye exam. Apparently I'm a little bit far-sighted in both eyes and have an astigmatism of roughly minus one diopter at 2 respectively 16 degrees (I don't remember the exact diopter values).

I was a little bit shocked, because like I mentioned, I'm not under the impression of being far-sighted and somehow all these numbers sound rather severe to me. Can someone unconfuse me on that matter? Are these strong values?


Cactus Jack 04 Feb 2017, 14:05

Fred,

Texas is a pretty decent place to live. I heard recently that about 1000 people per month are moving here from California and the Northeastern States. The cost of living here is reasonable and the business climate is excellent. The weather in the summer isn't all that great, but that is why we have Air Conditioning. Houston has a reputation of being HOT and HUMID from May to November. Someone asked me what the temperature was in the summer. I told them 72 degrees F. with brief episodes of hot and humid as I go from my Air Conditioned home to my Air Conditioned car and the Air Conditioned stores and offices. I don't think Houston would exist without Air Conditioning.

Many of the new residents have a saying "I wasn't fortunate enough to be born in Texas, but I got here as quick as I could.". Maybe next time, you can stay longer.

Feel free to contact me privately at cactusjack1928@hotmail.com, if you wish.

C.


Fred 04 Feb 2017, 13:23

Cactus Jack, ha! don't worry.. i get that! i've been to texas once, but never left the airport it was just a connection, unfortunately. but i actually really love texas and all of the american south! i read a lot of southern american literature, i told you i'm a literature guy before i think haha and southern literature is actually my favorite, and i always read in the original language so i'm somewhat familiar with the dialect too! i hope you have a nice week!


Cactus Jack 04 Feb 2017, 12:06

Fred,

The English question was pretty dumb. If you spent 6 months here, you probably have no problems with English. However, we don't think they speak English in New York and they are pretty sure we do not speak English in Texas.

C.


Cactus Jack 04 Feb 2017, 11:51

Fred,

I live in Houston, Texas. I look forward to hearing the results of trying the reading glasses over your regular glasses. I will be unavailable most of next week.

BTW, your English is excellent. Do you speak English or are you using a translator?

C.


Fred 04 Feb 2017, 09:28

Cactus Jack, that's so cool to know! i've heard about são josé dos campos but i've never been there. i've been to são paulo though for like three days. i live in rio grande do sul it's the southernmost state, i don't know if you know it. i don't blame you for not learning portuguese it's a very tricky language! sometimes people who are trying to learn ask me things and i can't help them because so much of it is just unwritten rules that you just have to remember. where do you live in the US? i was there last year for six months, in new york city with my brother. and i've visited multiple times in other occasions too! ..Thank you so much for your advice i'll try it this week! i don't really experience double vision though, i mean with the astigmatism a little bit but when i'm wearing glasses that gets corrected. Thank you for your time!


Cactus Jack 04 Feb 2017, 08:18

Fred,

Many years ago, in 1975, I spent a week in San Jose dos Campos at the Embraer plant, teaching the technicians how to install and trouble shoot autopilots in the Piper aircraft they were assembling under license. I didn't learn much Portuguese because the technicians wanted to practice their English.

I also have an acquaintances who lives in Sao Paulo. He has tried to teach me some Portuguese, but it may be hopeless at my age.

This may be a little hard to believe, but I am wondering if you are having some Presbyopia combined with some dry eye problems. The idea that Presbyopia is not a problem until your 40s is a myth. It can actually happen at any age and our modern world just makes the problem worse. I would like to suggest an inexpensive test. Get or borrow some Over-the-Counter reading glasses in the +1.50 to +2.00 range and try wearing them over your regular glasses when you are doing some close work. Try to blink more often and use some artificial tears occasionally. You may not need all of the above, but it would be a quick test to see if we are on the right track. Don't try the reading glasses by themselves because you need the Cylinder correction in your regular glasses.

You also could have a convergence issue, your eyes have to converge when you do close work or you would see double. Have you ever experienced double vision or trouble keeping images fused, particularly when tired?

Many ECPs, particularly older ones, have trouble understanding that our visual environment has changed and Computers, Smartphones and Tablets all involve close focusing. Young people, with Hyperopia are particularly vulnerable to Presbyopia problems at a much earlier age. The reading visual load required in most University programs, just makes the situation worse. I was moderately nearsighted when I was in University and had to get bifocals when I was 20 because of headaches.

Please let me know if any of this helps.

C.


Fred 04 Feb 2017, 05:21

Cactus Jack, the discomfort is worse when reading and studying! for close work. for just being outside and not doing any near work there's nearly no discomfort at all. i thought i had mentioned this im sorry! and i live in brazil actually! south of brazil close to uruguay, so i'm in the summertime right now! and no worries by the way there's no rush for you to reply i'll wait! :-) thank you..


Cactus Jack 03 Feb 2017, 20:44

Fred,

He increased your PLUS Sphere and reduced your Cylinder.

I don't think I have asked you when the discomfort occurs. When you are reading or studying, when you are outside, etc. We need some clues.

Also, I don't think I have asked you where you live. Tat can affect my suggestions.

I will be out of town for most of next week, but should be around over the weekend.

C.


Fred 03 Feb 2017, 17:38

Cactus Jack, i want your guidance on this.. haha! so, remember i was having problems with my eyeglasses and they were making my eyes hurt? i tried the eye drops that you suggested but they were of no help, unfortunately. so i went to an eye doctor again a new one and told him all about it, all the issues with my eyeglasses that i had been experiencing. i did an eye exam and he even dilated my pupils to see if everything was all right. turns out he got the same prescription again and told me my eyeglasses weren't made wrong or anything. so what he did was basically cut my prescription strength in half.. the astigmatism strength i mean.

and he gave me this:

OS +1.00 -0.75 cil x 175 OD: +1.00 -0.75 cil x 5.

my first prescription was this:

OS +0.50 -1.25 cyl x 175 OD +0.50 -1.50 cyl x 175

he told me this should help and if it doesn't for me to come back and that it really is hard for some people to adjust to my amount of astigmatism at first.. now here's the thing, i dont know if i should do these new lenses now, since my old ones weren't wrong. what do you say? will they really help me do you think? or should i just stay with mine until i eventually adjust 100%. thank you!!! sorry for the long post. also sorry for bothering you so much!


Fred 18 Dec 2016, 16:55

thank you cactus jack! always helpful... i will try the artificial tears With lubricant and if that doesn't help i'll let you know! also yes im a student i remember the last time we talked you told me your story about the cookies and i never replied back but just letting you know i thought it was pretty funny haha thank you!


Cactus Jack 18 Dec 2016, 11:44

Fred,

I don't thing it is astigmatism related, but don't rule that out, completely. You may have some Latent Hyperopia that is resolving and you need a bit more + Sphere. Before considering another eye exam, consider the possibility of dry eye problems. I don't remember if you ever said where you live, but it is pretty common in winter with low humidity. I suggest trying some Artificial Tears WITH lubricant. There are several brands. I look for those with Carboxymethylcellulose or (as strange as it seems) Polyvinyl Alcohol. Whenever I think of Alcohol, I think of a possible stinging sensation. That does not happen with Artificial Tears. They are pH balanced and typically the drops are soothing, particularly if they are approximately body temperature. If that helps or doesn't help, please let me know. I have a couple of other suggestions.

One other thing, you said you were a student and do a lot of reading. Very often, you don't blink enough when reading. You might try consciously blinking more when you read, to spread the tears you have around more in addition to the Artificial Tears.

C.


Fred 17 Dec 2016, 09:54

hey! i've been here before and you all seem very knowledgeable so here i am again! i have a new question.. so, my glasses are causing my eyes to burn lately like a burning sensation. sometimes they only show up when i first put them on, and sometimes they stay and i have to stop using them and rub my eyes and that often helps. i dont know if maybe my astigmatism isn't regulated anymore and i need a new prescription? even though i got mine only 6 months ago... i've been wearing them a lot and they've been fine only lately they've been causing this burning sensation and i dont know what it could be. anyone have any ideas? thank you! i didnt think glassses could make your eyes burn so im curious! also heres my prescription again in case anyone needs to know OS +0.50 -1.25 cyl x 175 OD +0.50 -1.50 cyl x 175. thank you!


Likelenses 28 Nov 2016, 20:33

Adam

See an eye doctor.

You will definitely get a prescription for glasses.

Do not be surprised if you get correction for both eyes.

A number of years ago a girl friend at the time,was having similar symptoms as yours.She thought that her left eye was bad only,but came away from the doctors office with a prescription slightly stronger for her right eye.

As I recall the Rx was, Rt eye +.25 -.75 cyl.

Lt.eye -.25 -.50 cyl.

After just a few days she was wearing the glasses full time,or she would get headaches.

Over the next few years the lenses got progressively stronger.When I last saw her she was around -2.00 sphere in both eyes,and the cyl was about-2.50 for the Rt.,and -1.50 for the Lt.

I could always tell when she needed stronger lenses,as she would squint badly with the glasses on.

She often complained that she thought that her Rt. eye had been perfect,and that the doctor set her up for ruining the vision in it by giving her a lense for it.


Adam 28 Nov 2016, 10:28

Dear Everybody,

According to online eye tests and my symptoms, I have astigmatism in my right eye (my left is perfect). It has never been a big problem because I could saw the eye chart with my right eye except the last row. On the other hand, I saw all the numbers and letters a bit blurred. It means that my distance vision is not that bad but the difference is easily recognizable compared to my left eye.

However, my near vision in my right eye is quite bad. It means I have to be close to the monitor to avoid squinting but it is never clear enough even if I'm very close. If I try to read the monitor with my right eye from normal distance, I am squinting very hard to read.

What do you think, should I visit the eye doctor to get glasses or contacts for my right eye or is it okay now? If I use both eyes, I have no problem but once I read that it is better to correct the worse eye. Thank you in advance!


Cactus Jack 22 Nov 2016, 21:21

Astigmaphile,

No chutzpah required. Just find an ECP that uses a regular Phoropter or Trial Lens Frame. Both have knobs for adjusting the Axis angle. Typically, you don't have to move it very far to find the sharpest image. If I am going to a new ECP, I always ask if he/she will let me fine tune the Axis at the appropriate point in the exam. I have never had a refusal. In fact, it tends to be an ice breaker and changes the atmosphere of the exam from an ECP to Dumb Patient, to one of Senior and Junior Colleagues working together to get the best prescription possible.

The relaxed, non-defensive attitude helps make the exam a pleasant memorable one for the Examiner. When I go back to the ECP, they often remember me and the exam become like a conversation between colleagues.

As you may recall, I have had some problems with Strabismus and getting the prescription right takes a bit longer. The ECP I like best, even has his receptionist schedule a double exam period for my appointments. He knows of my interest in vision and optics and I think he enjoys spending the extra time and taking the extra care.

Remember, the worst that can happen is that the ECP says NO! Of course, if that happens, that will be the last they see of me or my money. Once you try it, you will never want to do it any other way.

C.


astigmaphile 22 Nov 2016, 15:31

Cactus Jack,

I have never seen the newest model of phoropter for real but have seen them on YouTube. The whole thuing is controlled from a keypad or keyboard. There are no knobs on them. I wish that I had the chutzpah to ask an eye doctor to let me get my hand on the axis knob.


Cactus Jack 22 Nov 2016, 07:32

lisa,

That type of Phoropter is a recent innovation. It is controlled by the panel you described. I had an exam a few years ago with one of those machines in a room that was very small, equipped with a special screen that optically simulated a much longer room. I was not happy with the resulting prescription and never went back to that ECP for an exam. Many ECPs use an exam room with a mirror and projector or display that gives a true target distance of 20 ft or 6 meters. That works OK, but a very few ECPs actually have exam rooms arranged with the Snellen Chart display 20 ft or 6 meters from where the patient sits. That seems to be the best of all. The problem with that is that office real estate is expensive.

Unfortunately, I am not very familiar with the machine you described. I don't think it is possible for you to fine tune the Axis the way I described.

I can't imagine that any really good ECP would object to your asking questions and asking for an explanation of what you should be looking for. There is absolutely no way for the Examiner to see what you are seeing. They have to depend on how you answer their questions. An Eye Exam is NOT an inquisition. It actually should be a very pleasant experience that leads to sharp, comfortable vision.

Remember, that in most instances, YOU are paying the Examiner for their knowledge and skills. A good exam is actually a team effort. Sometimes, you have to shop around for an ECP that you feel comfortable working with. It is regrettable that some ECPs are not good communicators, just as some MDs are not good communicators. Don't be afraid to ask for explanations. You don't know their language, it is their responsibility to speak yours.

I hope this helps. May I as where you live?

C.


lisa 22 Nov 2016, 00:28

Thank you Cactus Jack for the comprehensive and clear explanation. You talk about turning a knob to change the axis yourself however there is no knob on the device that my optometrist uses its a white futuristic looking machine with lenses you look through and the optometrist gas some sort of control pad mounted on the worktop near him which he uses to change the lenses. So going back to GCs description of when the letters look short and squatty vs fuzzy but more accurate looking, what is the best choice? I always feel I answer it wrong and almost freeze up when it comes to that part of the test. Is it worth me actually stating out aloud what it looks like and ask the optometrist to be more clear in what he is asking.i think it could well be more of my own anxiety getting in the way of listening and taking the instructions though.


Cactus Jack 21 Nov 2016, 21:10

Oops, missed the title: " HOW TO STUDY FOR AN EYE EXAM"


Cactus Jack 21 Nov 2016, 21:09

CG and Lisa,

Here is a piece I wrote a while back that may be helpful. Pay close attention to the part about "fine tuning" the cylinder axis.

An eye exam is not like an exam that you might take in school and there is really no way to study for it. However, you can prepare for it and learn about your role in the exam. The best eye exams are a team effort between you and the Examiner. Part of the preparation is to learn what to expect, particularly if this is your first eye exam.

One important thing you need to keep in mind is that the Examiner has no way to experience what you are seeing. He/she has to depend on your answers to questions.

There are two parts to an eye exam. The first part is the Objective part. This part consists of:

1. Taking a Visual History where you describe your vision and the kinds of problems you are having.

2. Checking the internal pressure in your eyes for symptoms of Glaucoma. This is one of the very few parts of an eye exam that is even mildly uncomfortable and the discomfort only lasts for a few seconds. There are two basic ways to do the pressure test.

A. Using a special instrument to lightly touch your Cornea. Not to worry here. Before doing this type of test a drop of mild anesthetic will make sure you don’t even feel it.

B. There is a new type instrument that uses a puff of air directed against your cornea. No anesthetic is required, but the puff will startle you. The puff of air is harmless and there are huge benefits of detecting Glaucoma early before it can do damage.

3. Obtaining a preliminary estimate of your refractive error using an Auto-Refractor, or manually by using a small hand held instrument called an Ophthalmoscope or Retinoscope.

The Auto-Refractor is a relatively new instrument that was developed in conjunction with NASA to check Astronauts vision in space. You look into the machine with each eye individually at a scene or a pattern and the machine will adjust its internal lenses to focus the image you see on your retina. The Auto-Refractor only takes a few seconds for each eye and it then prints out your estimated prescription.

Some Examiners prefer to use manual methods that have been used for many years. Using an Ophthalmoscope or Retinoscope and a Trial Lens set or a Phoropter (a fancy machine with a built in lens set), the Examiner will look into your eyes and select the lenses that allow him to see your retina, most clearly.

The object of this part of the exam is to get a starting place for the Subjective part of the exam where you have to describe what you see.

Typically the Subjective part of the exam starts with the Right Eye shutter open and the Left Eye shutter closed.

Step 1 is typically determining the cylinder and axis of any Astigmatism correction you need. This is actually the hardest part of the exam because you will be asked to judge relative blurriness of two images rather than the sharpness of an image.

You will be shown a line of text and a supplemental lens will be rotated into place. This lens is a cylinder lens that is mounted on a 45 degree pivot and can be flopped back an forth to bracket a trial axis or orientation of the long axis of the cylinder lens. The thing that is confusing about this test is that the straight lines (strokes) of the letters will alternate in clarity as the lens is flipped back and forth depending on their direction. I suggest concentrating on an “O” if possible. Depending on your answers, the examiner will adjust the axis knob unit the image you see is equally blurry with the supplemental lens 45 degrees each side of the selected axis.

At this point the Examiner will probably swing the supplemental lens out of the way and may change the cylinder power while asking you which lens in clearer.

You may be uncomfortable, for your first exam, asking the Examiner to let you fine tune the axis, but I have found that most will appreciate your wanting to actively participate. The way that works is that he will place your hand on the Axis control knob and you move it back and forth a few degrees of the sharpest image, this time.

The next step is determining the Sphere correction. This is an easy part of the exam because all you have to do is pick the sharpest image, but there is a tricky part. Your auto-focus mechanism will try to help, if it gets a chance. The Examiner has a couple of ways to minimize the action of your ciliary muscles and crystalline lenses.

The Examiner can in effect sneak up on your Sphere prescription or he can use drops to Dilate your eyes. Lets talk about sneaking up on your prescription first. There are actually 4 lenses in your eye’s lens system. All of them are PLUS lenses and the total power is about +56 diopters. The only variable focus lens is the crystalline lens whose PLUS power is controlled by your ciliary muscles. For distance, your Crystalline lens is fully relaxed and has somewhere around +15 diopters. When you focus to read, your Ciliary Muscles squeeze the Crystalline lens to increase its PLUS power by the amount necessary to focus which depends on the distance to the object.

This will take a little thought to get your mind around, but if you are nearsighted, your lens system has too much PLUS for the distance from the lens system to your retina and you need MINUS lenses to neutralize some of that excess PLUS power. You ONLY have the ability to increase the PLUS power of your lens system. You have NO ability to reduce the PLUS power of your Crystalline lenses more that fully relaxed.

To try to keep your Ciliary Muscles and Crystalline lenses from getting in the act, the examiner will start with NOT ENOUGH MINUS or TOO MUCH PLUS (same thing) and gradually increase the MINUS one or two steps at a time, while reducing the size of the line you are asked to read. He will not tell you what power lens or what line you are looking at. Eventually, he will reach the 20/20 line and a lens power that lets you read it with no mistakes.

He will then follow the same procedure with your Left Eye.

When he has completed both eyes, he will open the shutters and you may see two images. This part of the test is to check your muscle balance using some prisms. He will probably ask you to tell him when the two images are aligned horizontally and then vertically. While the images are separated, you have an important check to make. Compare the sharpness of the two images. If they are not equally sharp, be sure and tell the Examiner which image is clearer. If there is a difference, he will likely reduce the sharpness of the clearest image until they match. The important thing at this point is that they match. That lack of sharpness will be corrected in the next phase with both eyes working together.

Next he will fuse the images so both eyes are working together and repeat the Sphere procedure by gradually increasing the MINUS or decreasing the PLUS until you see the smallest line of letters very clearly.

That pretty much completes the exam except for checking your near vision with a small chart about 14 to 16 inches from you.

Hope this helps.

C.


lisa 21 Nov 2016, 15:47

GC, thank you for posting that up, I have always thought the same. I actually dread that bit of the eye test. The optometrist puts those cluster of black dots up, no letters up. Sometimes with the lenses choices the dots look like they've been smudged a bit. I don't understand why they make you choose when the two options look equally rubbish vision wise.


GC 21 Nov 2016, 15:41

I'm getting ready to go in for my eye exam - have been getting glasses for the past 3 years and am never quite happy with the prescription. My question sounds basic- but it gives me fits during the exam. Captain Jack said below: When refracting for astigmatism, you are being presented lens choices and being asked to judge which is clearest.

As I take my eye exam- I struggle with how to answer when the letters both change shape and change in fuzzyness. Is a letter that looks short and squatty, but is less fuzzy "better"? Or am I supposed to choose the letter that looks more accurate (i.e. not short and squatty), even if it's fuzzier around the edges. Can you tell me how to answer the question as to which is better, when the choices both seem off in different respects?

Thanks!


antonio 19 Nov 2016, 16:41

swap ,

sounds to me she will soon need them for more things,

as her eyes continue to go a little worse,

so just wait and see what happens and if possible encourage her to wear them, if that helps :)

best regards, antonio


Eudora 18 Nov 2016, 20:05

Hi -- I've worn a contact in my right eye (only) for years for nearsightedness (now -2.5). Today the optician suggested I also try a lens in my left eye, which just needs correction for astigmatism (.75). I'm trying to decide if it's worth it (both in terms of improved vision & cost). I've only tried the left lens for a few hrs, and things are seeming slightly blurry (but maybe that would improve with a little time?). Thoughts?...Thank you.


swap 29 Oct 2016, 21:03

Since childhood I like girls wearing glasses, ,

My girlfriend had prescription of -0.75 for both eyes before 2 years. She never wear glasses, she didn't like it. One and half years passed her prescription increased up to -1.25 for both eyes. Still she doesn't want to wear glasses, ,, she just wears it occasionally for driving, or working on computer. She can't see long signs. Can't read distant words, nameplates. Now again she complaining about eyes. Does it mean her prescription increased? Are there any chances of increasing her prescription further upto -3, -4 ?


Michael 28 Oct 2016, 17:04

Soundmanpt-Yes I recall you telling us about your hairdresser friend before. Sam's situation seems very similar to that. So I agree with what both you and Plus Tony are saying. Sam should wear his or her glasses full time for two weeks and then make up his or her mind how much to wear them after that. But Sam may decide it is more convenient to just keep them on and if the headaches disappear when wearing glasses that would be a clue to wear them full time.


Soundmanpt 28 Oct 2016, 14:08

Plus Tony

I know I had told about her before but I felt like what happened with her was very much what Sam has going on.


Plus Tony 28 Oct 2016, 13:09

Soundmanpt

I had forgotten about the example of your hairdresser friend but it is an excellent example of how even a seemingly minor prescription can make a huge difference to a person's quality of life.


Soundmanpt 28 Oct 2016, 11:11

Sam

What "Plus Tony" has already told you is pretty accurate. But I think that many doctors recommend full time wear even with a slightly weaker prescription than -1.00 for astigmatisms. It seems your ECP (eye care professional) must feel that way as well since he / she recommended you wear your glasses full time. Your eyesight is still really quite good and you should be able to still see very well without your glasses. But unlike being nearsighted or farsighted astigmatisms often cause headaches early on. So considering how much your reading either from a book or on your computer it's understandable that you're getting headaches and they will only get worse if you don't wear your glasses. Like "Plus Tony" said when you get your glasses you do need to wear them full time anyway for at least the first 2 weeks so your eyes can adjust to your glasses. And its very possible that at first you may feel a bit dizzy and feel like the room is tilted and even spinning around but after a short time things will straighten out and you will be seeing fine with your glasses. You can expect that during those 2 weeks you won't be bothered at all by headaches.

I have a friend that was much like you only she wasn't even doing any real close work she cut hair. But like you she was getting frequent headaches nearly everyday after only being at works a few hours. She went to her doctor and was advised to get her eyes checked. She wasn't having any problems with seeing and was sure she had perfect vision but she did go for an eye exam as advised. She was able to see the eye chart perfectly but when the exam was finished she was shocked to be told that she needed to start wearing glasses. The doctor wrote her a prescription fro glasse with this prescription. R plano -.75 180 / L plano -.75 180. And she was even more shocked when she was told that she needed to wear her glasses full time. She got her glasses but was determined not to wear them because she could see everything just fine, But the very next day she started getting her usual headache and she did have her glasses in her bag so she pulled them out and put them on. After only having her glasses on for a short time the headache was gone. She kept her glasses on the rest of the day. The next day she still wasn't convinced that it was the glasses that made the headache go away she she didn't wear her glasses but just like the day before after a couple hours at work she started feeling a headache coming on. Again she put on her glasses and again the headache was soon gone. From then on she has been wearing her glasses full time. She can still see nearly perfect without her glasses but she does admit that it is easier to see with her glasses on now.


Michael 28 Oct 2016, 06:40

Sam- I concur with everything that Plus Tony has told you. But ultimately how much or how little you wear your glasses is entirely up to you.


Plus Tony 28 Oct 2016, 04:38

Sam

Welcome to the world of glasses wearing. I should start by saying that while I am a full time glasses wearer I do not have astigmatism but have learnt a little about it from reading various exchanges over the years on this site.

Astigmatism (which means your eyes are shaped more like rugby balls than tennis balls) affects vision at all distances. Your prescription includes a tiny correction for short sightedness (the -0.25 sphere correction) and a slightly stronger astigmatism correction of -0.75 (Right) and -0.50 (left). The other numbers refer to the angle of your astigmatism in each eye.

I have heard it said that opticians recommend full time wear for astigmatism when it reaches -1.00 but I would recommend that you definitely wear your glasses full time to start with for at least two weeks. Why? Getting used to an astigmatism correction can be challenging. The room might look like it is spinning and angles may seem weird. If you wear your glasses all the time while you are getting used to this it'll settle down after a couple of days (if not sooner). It is best to be disciplined about this and get into a routine of putting them on as soon as you get up and keeping them on until you go to bed. Get your friends and family used to seeing you in glasses and don't be shy about it. It is quite normal for someone to start wearing glasses full time straight away (that is what I did) but it depends on the prescription and the individual's desire for clear vision. I have a relatively low prescription myself but know others with lower prescriptions who also feel more comfortable keeping their specs on all day. Ultimately it is up to you.

After the bedding in period is over you will have a better idea of when you need to wear your glasses (but you may well feel that it is easier to keep them on all the time and if you do it isn't going to do your eyes any harm). There are many advantages to this, not least clear vision but also glasses are much harder to scratch, break or lose if you're wearing them!

Your visual environment is an important consideration. What are you studying?


Sam 28 Oct 2016, 02:15

Hi, I've just been for an eye test. Since starting university a month ago I've been getting headaches when I've been using the computer or reading for a long time. It wasn't a problem when I was doing my A levels but I've had a year off since then. I thought I would b given glasses for when my eyes hurt, but the optician said the problem was that I've got astigmatism so I definitely need to wear glasses whenever I am studying, driving, watching tv or concentrating. She said that it would probably be best to wear glasses all the time when I get them. The card she gave me read right eye -0.25 -0.75 10 and left eye -0.25 -0.50 5. I am picking up the glasses on Tuesday. Most people I know with glasses start by wearing them some of the time and only start wearing them constantly later on. Will it be weird if I start wearing glasses all the time straight away and can I get away with part time wearing glass s?


Soundmanpt 18 Oct 2016, 08:56

Beachin'

You're quite welcome. When you got your previous glasses 3 years ago the one mistake you made was by not wearing your glasses full time until your eyes adjusted to them. That way it wouldn't have taken 6 months for your glasses to become comfortable. Then once your eyes adjusted you could have gone to part time wear which is really all you require. Your ECP (eye care professional) should have recommended that to you when he / she fitted your glasses.

I agree if your getting new glasses you should order them without the astigmatism for your left eye, but if you still like your current glasses it won't do you any harm to wear them as well. Certainly still a very good backup pair to maybe keep in your car.


Beachin' 17 Oct 2016, 19:36

Thanks Soundmanpt! When I was originally prescribed my previous script the glasses made me dizzy so I thought it was possible I was over prescribed. However, I knew it was normal for a person with an astigmatism to take a while (in my case 6 months of part time wear) to adjust so I didn't talk to my doctor about it. Maybe I was right to question things? Maybe my astigmatism really disappeared?

I don't get dizzy anymore when I wear them but I think I'll go ahead and get new glasses without the astigmatism in my left eye.


Cactus Jack 17 Oct 2016, 19:13

Fred,

Nothing wrong with being curious. I am also afflicted with curiosity. You are likely to be dealing with glasses or vision correction for many years and the more you understand about how vision and optics work, the better decisions you can make.

As a student, you may have some budget issues. Depending where you live, glasses can be very expensive. You may find it desirable to consider ordering glasses online. Many of our members have had good experiences with Zenni Optical. They offer single vision glasses for as low as US$6.95 depending on frame choice, lens material selection, and options. Shipping is extra. Let me know if you are interested, we can help you with your first order.

I remember when I was 19 and in University. I was on an allowance that did not permit many pleasures as were many of my fellow students. I remember a friend inviting me to go to a convenience store to get some snacks. I told him that I was broke until my Dad sent me my next allowance. He said, "In that case, you can look at the cookies and if you are lucky, I will share a few of mine." I was not offended because I knew that the situation would be reversed when I was in funds and he was not. That is what good friends are for.

C.


Michael 17 Oct 2016, 14:23

Fred- We are all here to help you. But no way I would try to tackle explaining the technical stuff. I always leave that up to Cactus Jack.I think all of us here were pretty much on board as far as telling you we think it would be best to wear your glasses full time because of the astigmatism. Your sphere though is very low. We would never steer you in the wrong direction. Glad to hear wearing your glasses full time seems to be working out well for you. I along with some others here told you your eyes would feel more comfortable when you wear your glasses.No eyestrain and no headaches.


Fred 17 Oct 2016, 14:05

Thank you Cactus Jack! that's very informative! thank you... i mentioned in my first post that i'm 19 but not my occupation. im a student! literature aficionado so i do a lot of close reading every day haha.. and actually i did read about your method of "fine tuning" before! when i first came on here i was reading the post and saw you mentioned that so it's ok! thank you. and sorry to be bothering i was just curious about things!


Cactus Jack 17 Oct 2016, 03:49

Fred,

I am very glad to hear that we didn't steer you wrong about glasses.

To answer your question: Astigmatism typically does not go away with age.

Usually, Astigmatism is caused by uneven curvature of the front surface of the Cornea. Ideally, the Cornea should be shaped like a slice of the side of a glass sphere. The exact cause of Astigmatism is unknown, but it appear that uneven growth of the eyeball may cause uneven tension around the Cornea and distort the sphere into the shape of a slice from the side of a glass American Football. It is possible that eyelid tension can cause Corneal distortion. Insufficient tears (dry eyes) can also cause Corneal distortion.

The distortion occurs when the curvature of the Cornea is steeper in one direction (short axis) than it is in the other (long axis). The actual difference in curvature is very small compared to a perfect Sphere. It is on the order of 0.3 mm per diopter of Cylinder. A little bit goes a long way.

Actual Astigmatism changes very slowly, but there are two common things that make the changes seem fast. The part of the eye exam where the Cylinder and Axis are measured is extremely subjective. The accuracy of the prescription is determined by the skill of the patient in judging relative blurriness of two lenses. It isn't easy. I have written a simple method of "Fine Tuning" Cylinder and Axis, but you need to make a deal with the examiner, prior to the exam, and you need to understand the procedure. Let me know if you are interested.

The second common cause of a really big change in prescription is the use of two different methods of writing an optical prescription. Traditionally, Optometrists and Lens Makers use Minus (-) Cylinder notation and Ophthalmologists (M.D.s) use Plus (+) Cylinder notation. Your prescription: OS +0.50 -1.25 cyl x 175 OD +0.50 -1.50 cyl x 175 would be written: OS -0.75 +1.25 cyl x 85 OD -1.00 +1.50 cyl x 85 by an M.D. There is a simple procedure for converting from on Cylinder notation to the other. The two prescriptions are optically identical. If a lens maker is given a prescription with + Cylinder notation, he converts it of - notation and makes the lenses.

As you can see, the difference is enough to scare anyone who does not understand how this stuff works.

Curiously, you may find that your brain remembers the algorithms for processing the images with your glasses and without them. Before you put on your glasses and after you take them off, it will load the old algorithm. When you put on your glasses it will load the new one. The difference will be the comfort you experience with the glasses because your glasses are optically correcting the images before they are delivered to your brain.

I don't think you have mentioned your age or occupation.

C.


Fred 16 Oct 2016, 16:52

hey it's me again! so i've been wearing my glasses basically full time now as suggested and boy can i notice the difference! haha you all were right about my brain and my eyes being very trained on correcting my astigmatism... my eyes really feel a lot more comfortable overall now. anyways i was also wondering, will my eyes get worse or better over time? i read that astigmatism diminishes over time is that true? i was wondering if over time mine could decrease to the point i won't even need any correction anymore. could that happen?


Tom1 14 Oct 2016, 14:23

Sorry my reply is to SD .


Tom1 14 Oct 2016, 14:21

Your prescription is very low. Astigmatism may affect your close vision a little bit as well, but if you don't feel you need a perfect vision you can wear part time or even not at all. Do you have driving glasses? Do you need glasses to drive? Maybe not..


Soundmanpt 14 Oct 2016, 12:23

Beachin'

So there was no change in your right eye from your last exam 3 years ago. And the only change in your left eye was that apparently there was no indication of any astigmatism in that eye at this eye exam. It is very possible that it has gone away since your last eye exam. Now even though it seems to be gone if your glasses still seem good to you then unless you just want new glasses you should be fine with continuing wearing your current glasses. You should be able to determine how well your able to see with your glasses on by covering your right eye and checking your sight with your left eye. If everything seems fine then their is no need for new glasses.


Cactus Jack 13 Oct 2016, 21:47

SD,

Only if you like to see comfortably and have good vision.

1. Have you had the prescription filled?

2. May I ask your age?

3. Is this your first prescription?

C.


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