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Hyperopia and Presbyopia Progression

For and about anyone having difficulty seeing near/reading.

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John S 16 Jan 2017, 12:24

Soundmanpt,

Please re-read what Newspex posted. I think you missed when he took he glasses off, his distance vision was blurry.


Soundmanpt 16 Jan 2017, 10:53

Newspex

Your eyes are still adjusting to the change in your prescription which is very normal. The same thing likely happened with your previous glasses when you first got them but as your eyes adjusted you didn't have the blur anymore.


Newspex 16 Jan 2017, 10:47

I have recently upgraded my reading/ pc glasses, but I have noticed that

after wearing them for a prolonged spell they make distance vision blurry for about 10 minutes when I remove them.

The old pair didn't seem to do it.


Cactus Jack 15 Jan 2017, 18:46

Jay,

Sometimes the ES server does not respond very quickly. If the background of the Submit button turns BLUE when you click on it, your post is acceptable. You don't need to click again. Multiple posts are usually caused by the server being slow to respond your first click. If the Submit button turns Blue, just be patient and the server will retrieve your post when it can. It rarely take more than 30 seconds.

C.


Jackson 15 Jan 2017, 16:48

Jay,

Yes, they are just reading glasses.


Jay 15 Jan 2017, 15:49

My apologies. I was having trouble posting.


Jay 15 Jan 2017, 15:45

Just getting reading glasses, Jackson?


Jay 15 Jan 2017, 15:45

Just getting reading glasses, Jackson?


Jay 15 Jan 2017, 15:45

Just getting reading glasses, Jackson?


Jay 15 Jan 2017, 15:45

Just getting reading glasses, Jackson?


Jay 15 Jan 2017, 15:45

Just getting reading glasses, Jackson?


Jay 15 Jan 2017, 15:45

Just getting reading glasses, Jackson?


Jay 15 Jan 2017, 15:44

Just getting reading glasses, Jackson?


Jackson 13 Jan 2017, 16:03

Seems my age has finally caught up to me. I was having a little trouble reading the paper, so I decided to get my eyes checked, and turns out my intuition was correct. I am getting my glasses later today.


Cactus Jack 11 Jan 2017, 18:26

There are two kinds of Hyperopia and two kinds of Myopia. True Hyperopia and Myopia are typically caused by a mismatch between the length of the eyeball and the total optical power of your eye's lens system. After your eyeballs stop growing, usually in your late teens or early 20s. The don't change size (length) very much. The critical thing here is the distance from the back of the Crystalline Lens to the Retina. The eyeballs like most other body parts don't shrink much after they have grown. They would have to shrink for for true Myopia, where the eyeball is too long, to turn into Hyperopia where the eyeball is too short.

I suspect you may have had False Myopia on top of True Hyperopia. They can occur together because False or Pseudo Myopia (ctually the same thing as Latent Hyperopia is caused by the Ciliary Muscles and Crystalline Lenses not fully relaxing back to their high PLUS power. The way it is supposed to work, if you don't need correction) is that the Ciliary Muscles and Crystalline Lenses are fully relaxed (at minimum PLUS power for distance. If you focus close your Ciliary Muscles squeeze the Crystalline Lenses and increase their Plus power by an amount determined by Sir Isaac Newton's most fundamental optical formula. Lens Power = 1 meter / Focal Distance. In practice that means to focus at a typical reading distance of 40 cm or 16 inches, you need +2.50 internally using your Ciliary Muscles and Crystalline Lenses or externally from glasses. If your Ciliary Muscles don't fully relax for any reason, you have False Myopia or if you are actually farsighted and need the extra Plus for distance, you have Latent Hyperopia.

If you have False Myopia, when you start wearing glasses with an Add, often your Ciliary Muscles gradually relax over time and you become less and less Myopic. If you are actually Hyperopic, you finally need Plus glasses for distance.

You did not mention your prescription for Myopia or present prescription for Hyperopia. That would help understand what has happened. It is really pretty common.

C.


john 11 Jan 2017, 02:27

Bailey.- Yes it happened to me.I had myopia all my life like you and when I got bifocals I slowly went to hyperopia .There was a year where I needed no distance correction except for my astigmatism .I am older than you and now have trifocals which happens when your add goes to plus 2.00 or more.Eye Drs don't like to predict what is going to happen because everybody is different .It may not happen to you but it could. Hope this helps.


Soundmanpt 11 Nov 2016, 08:53

Dan

Thanks for the update of your fiancee's recent eye exam. You and others were expecting that in the 3 years since she got her last glasses and considering her own comments to you about her vision that she almost certainly would be needing an increase in her glasses. She even said that when she doesn't wear her glasses when she is on her computer that her eyes don't focus well and it had become much more difficult trying to read small print without her glasses and even with her glasses small print was blurry. It did seem like she was almost certain to be getting stronger glasses. But instead she no longer has any plus in her new prescription. Now she only has astigmatisms. A bit more in her right eye than her left eye which is actually nearly perfect now. So please provide us with further updates once she gets her new glasses as to how she gets along wearing them. The good news for you is that since she is so used to wearing glasses already she will most likely continue wearing them even though she only barely needs them.


Dan 11 Nov 2016, 06:19

Realized I never posted my fiancée's new prescription (see discussion in September on this thread). Some had speculated (including myself) that she would need more plus. In fact, she just needed more astigmasitn correction. New prescription

OD 0.00 -1.00x95

OS 0.00 -0.25 x 45

My prescription remained quite boring, -1.75 ( up from -1.50)


Michael 30 Oct 2016, 11:19

swap- I liked it when you said you wished your girl friend would wear her glasses 24/7. I know what you are saying but I don't think you really mean 24/7. I don't think it would be a good idea for her to wear them when either showering or sleeping.But it might not be a bad idea if she wore them most of the rest of the time.If she did she might stop having headaches.


Michael 30 Oct 2016, 08:59

swap- You are welcome. I am trying to advise you as best as I can and let us know if we can be of any more assistance.


swap 30 Oct 2016, 08:14

THANKS Michael


Michael 30 Oct 2016, 07:56

swap-The headaches are a clue I think that your girl friend needs to wear her glasses more than she is if not full time. The first thing I would suggest is have her get an eye exam ASAP. I have a feeling she may have some astigmatism and that is why she is getting headaches and eye pain which I guess is getting worse.I am almost certain she needs an updated script and it might be a good idea if that is the case for her to wear it full time.

Does she wear her glasses all the time when driving?She definitely needs to do that. I don't know what the laws are in the state you live in but in the majority of them you have to periodically pass an eye exam to renew your driver's license and I have serious doubts your girl friend would be able to without correction. If her uncorrected vision is less than 20/40 I don't think she could pass a DMV vision screening in any state without wearing her glasses

I am assuming she wears her glasses in class for lectures and to read the board.Am I right? And how about for studying? If she gets headaches when using the computer I am guessing she does when reading books and doing homework as well.

But it can be a pain to keep on putting your glasses on and taking them off. Does your girl friend do that? It makes me very nervous when I see somebody do that. If you are constantly putting them on and taking them off you are probably just better off leaving them on. Plus you are less apt to either lose or break them if you keep them on your face.

And if your girl friend does go for an eye exam have her ask either the doctor or optician for advice as to when she should wear her glasses. It is my experience that most of them don't give you advice unless you ask. That has always been a pet peeve of mine.They don't seem to offer advice even to first time wearers.The optician usually just hands you the glasses and sends you on your way.

But if you want your girl friend to wear her glasses more tell her how good she looks in them. And I am sure she looks great.Encourage her but don't push her or it will have the opposite effect. But she will come around because at some point being able to see well becomes more important than vanity. And I don't think she enjoys getting headaches. My guess is if she wears her glasses that will alleviate that problem. But she does need to go for an eye exam and get an updated script. My guess is she needs a stronger prescription and she may have some astigmatism as well even if she didn't before.


swap 30 Oct 2016, 07:19

Michael- thanks for your reply friend

She is still student.

She uses glasses to see distant objects only when necessary, also she wears them for computer because she said working on computer without glasses gives her headache. Now a days she is constantly complaining about headache and eyes pain, ,,,

But now a days she is wearing it frequently as compared to past. And I really would like to see her wearing glasses 24×7. I think if her prescription increased she will use it. When I forced her to wear glasses she wears for few minutes again remove it when I ask why don't you wear them all times she replied I use when I need to read number plates and sign boards and to drive


Michael 30 Oct 2016, 06:22

swap- Does your girl friend work or is she still in school? As Cactus Jack said if you can give us your girl friend's full script we would be able to help you more. Her myopia appears to be pretty mild but we don't know whether or not she has any astigmatism. Based on the info you gave us I would say it would benefit your girl friend to wear glasses for distance activities if she wants to see well. Like movies, concerts and sporting events and maybe for TV too. But especially for driving. I doubt she would be able to pass a DMV vision screening but not 100% sure.But she should wear her glasses whenever she drives especially at night or when the weather is inclement. Driving at night without glasses would have to be difficult for her.

Astigmatism can affect both your distance and near vision. Even a small amount. If your girl friend does have some astigmatism unless it is a very small amount she might find her vision more comfortable if she wears her glasses full time. Does she get any headaches? If she does that may be a clue that she should be wearing her glasses. I am a little surprised that she does wear her glasses at least occasionally when working on the computer if she is just myopic with a relatively mild script.

Yes it is definitely possible if not probable that your girl friend's vision has gotten worse. Is she planning to go for another eye exam? It seems that she is not going to be able to avoid wearing glasses at least some of the time. I guess your goal is to have your girl friend wear glasses full time. Am I right? But if her script got up to -3 or -4 for both eyes that should do it for sure unless she is very stubborn. At some point though being able to see will take priority over vanity.

But don't try to push your girl friend into wearing her glasses more because it will likely have the exact opposite effect. She will have to decide herself.


Michael 30 Oct 2016, 05:16

Why do people have duplicate posts? Bailey has his or her post here five times. Maybe when somebody posts for the first time the person is uncertain how to do it. But shouldn't the moderator remove duplicate posts? It does cause a lot of clutter in the thread.


swap 30 Oct 2016, 04:29

Cactus jack

Sorry for my 3 posts and thanks for your reply,

She is 21 years old now

Her mom wears glasses with minus prescription

And her prescription as I know -1.25 for both eyes, ,,,

Maybe this information would be helpful for you


Cactus Jack 30 Oct 2016, 01:31

sawp,

ONE post on ONE thread is enough. As it happens, your GF has Myopia or nearsightesness, there may also be some Astigmatism, so all three of your posts are on the wrong threads. The Vision thread might have been a good one.

The biggest factor in Myopia is genetics. Do any of her close relatives also wear Minus glasses. The next most important thing is her age. Lastly, her visual environment is very important. What is her occupation?

Also, her complete prescription is very helpful in predicting future increases in Myopia.

C.


swap 29 Oct 2016, 21:05

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 (I wish so)?

Please guide if anyone has knowledge


Bailey 23 Oct 2016, 21:45

Hello Cactus Jack,

I see that you've helped a lot of people understand vision and vision problems. I was wondering if you could help me as well.

I'm wondering if I am gradually turning from being mildly nearsighted to going farsighted.

I'm a 38-year old real estate broker, but I first began wearing glasses when I was 23. These were for fairly mild myopia, and I was quite stable at -1.50 in both eyes. (Very slight astigmatism of -0.25 as well, but I won't dwell on this since it is fairly constant.)

When I was maybe 28 or 29, my left eye slightly increased to -1.75, but at my next eye exam it reverted back to -1.50.

Then, at 32, the slow decline began: My right eye dropped to -1.25. In 2013, when I was 35, my left eye dropped from -1.50 to -1.25, and my right eye dropped from -1.25 to -1.00.

One thing to note: Even when I first began wearing glasses, I always found it more comfortable to take them off when I read. For this reason contact lenses never really worked very well for me. For the last three years at least, I simply have not been able to read without taking them off.

I just had a new exam in August of this year, and here is my new prescription:

R -0.75 -0.25 135 add +1.50

L -1.00 -0.25 110 add +1.50

So you can see that my nearsightedness has decreased further, and I now have a reading addition. I'm actually relieved to get the extra reading help because I knew it was overdue. However I cannot believe how the myopia continues to drop. It's certainly nice, but I wonder where I'm going.

Is it possible that I drift toward hyperopia? Any idea on the rate at which this could happen, given my age? What kind of physiological mechanism could cause the eyeball to shrink?

I asked my eye doctor about becoming hyperopic, and she was not very clear. Instead she focused on my emerging presbyopia. She said, "It's certainly possible, but right now we should look out for increases in your reading."

Thanks for your help, and if anyone else has any personal experience, please share!


Bailey 23 Oct 2016, 21:44

Hello Cactus Jack,

I see that you've helped a lot of people understand vision and vision problems. I was wondering if you could help me as well.

I'm wondering if I am gradually turning from being mildly nearsighted to going farsighted.

I'm a 38-year old real estate broker, but I first began wearing glasses when I was 23. These were for fairly mild myopia, and I was quite stable at -1.50 in both eyes. (Very slight astigmatism of -0.25 as well, but I won't dwell on this since it is fairly constant.)

When I was maybe 28 or 29, my left eye slightly increased to -1.75, but at my next eye exam it reverted back to -1.50.

Then, at 32, the slow decline began: My right eye dropped to -1.25. In 2013, when I was 35, my left eye dropped from -1.50 to -1.25, and my right eye dropped from -1.25 to -1.00.

One thing to note: Even when I first began wearing glasses, I always found it more comfortable to take them off when I read. For this reason contact lenses never really worked very well for me. For the last three years at least, I simply have not been able to read without taking them off.

I just had a new exam in August of this year, and here is my new prescription:

R -0.75 -0.25 135 add +1.50

L -1.00 -0.25 110 add +1.50

So you can see that my nearsightedness has decreased further, and I now have a reading addition. I'm actually relieved to get the extra reading help because I knew it was overdue. However I cannot believe how the myopia continues to drop. It's certainly nice, but I wonder where I'm going.

Is it possible that I drift toward hyperopia? Any idea on the rate at which this could happen, given my age? What kind of physiological mechanism could cause the eyeball to shrink?

I asked my eye doctor about becoming hyperopic, and she was not very clear. Instead she focused on my emerging presbyopia. She said, "It's certainly possible, but right now we should look out for increases in your reading."

Thanks for your help, and if anyone else has any personal experience, please share!


Bailey 23 Oct 2016, 21:44

Hello Cactus Jack,

I see that you've helped a lot of people understand vision and vision problems. I was wondering if you could help me as well.

I'm wondering if I am gradually turning from being mildly nearsighted to going farsighted.

I'm a 38-year old real estate broker, but I first began wearing glasses when I was 23. These were for fairly mild myopia, and I was quite stable at -1.50 in both eyes. (Very slight astigmatism of -0.25 as well, but I won't dwell on this since it is fairly constant.)

When I was maybe 28 or 29, my left eye slightly increased to -1.75, but at my next eye exam it reverted back to -1.50.

Then, at 32, the slow decline began: My right eye dropped to -1.25. In 2013, when I was 35, my left eye dropped from -1.50 to -1.25, and my right eye dropped from -1.25 to -1.00.

One thing to note: Even when I first began wearing glasses, I always found it more comfortable to take them off when I read. For this reason contact lenses never really worked very well for me. For the last three years at least, I simply have not been able to read without taking them off.

I just had a new exam in August of this year, and here is my new prescription:

R -0.75 -0.25 135 add +1.50

L -1.00 -0.25 110 add +1.50

So you can see that my nearsightedness has decreased further, and I now have a reading addition. I'm actually relieved to get the extra reading help because I knew it was overdue. However I cannot believe how the myopia continues to drop. It's certainly nice, but I wonder where I'm going.

Is it possible that I drift toward hyperopia? Any idea on the rate at which this could happen, given my age? What kind of physiological mechanism could cause the eyeball to shrink?

I asked my eye doctor about becoming hyperopic, and she was not very clear. Instead she focused on my emerging presbyopia. She said, "It's certainly possible, but right now we should look out for increases in your reading."

Thanks for your help, and if anyone else has any personal experience, please share!


Bailey 23 Oct 2016, 21:43

Hello Cactus Jack,

I see that you've helped a lot of people understand vision and vision problems. I was wondering if you could help me as well.

I'm wondering if I am gradually turning from being mildly nearsighted to going farsighted.

I'm a 38-year old real estate broker, but I first began wearing glasses when I was 23. These were for fairly mild myopia, and I was quite stable at -1.50 in both eyes. (Very slight astigmatism of -0.25 as well, but I won't dwell on this since it is fairly constant.)

When I was maybe 28 or 29, my left eye slightly increased to -1.75, but at my next eye exam it reverted back to -1.50.

Then, at 32, the slow decline began: My right eye dropped to -1.25. In 2013, when I was 35, my left eye dropped from -1.50 to -1.25, and my right eye dropped from -1.25 to -1.00.

One thing to note: Even when I first began wearing glasses, I always found it more comfortable to take them off when I read. For this reason contact lenses never really worked very well for me. For the last three years at least, I simply have not been able to read without taking them off.

I just had a new exam in August of this year, and here is my new prescription:

R -0.75 -0.25 135 add +1.50

L -1.00 -0.25 110 add +1.50

So you can see that my nearsightedness has decreased further, and I now have a reading addition. I'm actually relieved to get the extra reading help because I knew it was overdue. However I cannot believe how the myopia continues to drop. It's certainly nice, but I wonder where I'm going.

Is it possible that I drift toward hyperopia? Any idea on the rate at which this could happen, given my age? What kind of physiological mechanism could cause the eyeball to shrink?

I asked my eye doctor about becoming hyperopic, and she was not very clear. Instead she focused on my emerging presbyopia. She said, "It's certainly possible, but right now we should look out for increases in your reading."

Thanks for your help, and if anyone else has any personal experience, please share!


Bailey 23 Oct 2016, 21:42

Hello Cactus Jack,

I see that you've helped a lot of people understand vision and vision problems. I was wondering if you could help me as well.

I'm wondering if I am gradually turning from being mildly nearsighted to going farsighted.

I'm a 38-year old real estate broker, but I first began wearing glasses when I was 23. These were for fairly mild myopia, and I was quite stable at -1.50 in both eyes. (Very slight astigmatism of -0.25 as well, but I won't dwell on this since it is fairly constant.)

When I was maybe 28 or 29, my left eye slightly increased to -1.75, but at my next eye exam it reverted back to -1.50.

Then, at 32, the slow decline began: My right eye dropped to -1.25. In 2013, when I was 35, my left eye dropped from -1.50 to -1.25, and my right eye dropped from -1.25 to -1.00.

One thing to note: Even when I first began wearing glasses, I always found it more comfortable to take them off when I read. For this reason contact lenses never really worked very well for me. For the last three years at least, I simply have not been able to read without taking them off.

I just had a new exam in August of this year, and here is my new prescription:

R -0.75 -0.25 135 add +1.50

L -1.00 -0.25 110 add +1.50

So you can see that my nearsightedness has decreased further, and I now have a reading addition. I'm actually relieved to get the extra reading help because I knew it was overdue. However I cannot believe how the myopia continues to drop. It's certainly nice, but I wonder where I'm going.

Is it possible that I drift toward hyperopia? Any idea on the rate at which this could happen, given my age? What kind of physiological mechanism could cause the eyeball to shrink?

I asked my eye doctor about becoming hyperopic, and she was not very clear. Instead she focused on my emerging presbyopia. She said, "It's certainly possible, but right now we should look out for increases in your reading."

Thanks for your help, and if anyone else has any personal experience, please share!


Cactus Jack 13 Oct 2016, 21:43

Guest,

It is very unlikely. You haven't provided enough information to offer a good answers to your questions. Here are a few questions:

1. Do you presently wear glasses or contacts?

2. What is the complete prescription?

3. What is your occupation?

4. Where do you live>

I may have more questions after you answer those.

C.


Guest 13 Oct 2016, 13:25

Hello all. I have a question I can't find an answer for anywhere in net. I'm in my 20s and I'm mildly farsighted. Is it true farsightedness can turn into nearsightedness? Or will my farsightedness just increase? was told by a friend that farsightedness doesn't increase while you're in your 20s but it can become myopia. Is that true? Seemed odd to me.


Kris 08 Oct 2016, 22:40

Like lenses,

The conversation with my ECP before I started using prism was about when I would need it, not if. I thought I could put it off for several years, but he basically informed me that he was waiting for me to admit I had a problem. He made sure I understood that I wouldn't be able to go back once I started. I was surprised that I went up on my prescription as quickly as I did and hope it doesn't mean I'll end up needing a large prism prescription in the future. I didn't think my symptoms were too bad before prism, but in looking back I now realize I had more issues with double vision than I was willing to admit. I also had a lot of eye strain that has improved. I'm glad to hear you've been able to avoid them.

I don't know what material my lenses are, but the prism isn't really noticeable in the frames I wear. The outer edge is definitely thicker than the inner, but you have be looking for it to notice. They aren't Heavy either.

Overall, I'm much more comfortable than I was before I started wearing prism. If I were to be totally honest, I still have some eye strain when I'm doing a lot of computer work and do feel like my eyes are working to maintain fusion. So far though, no real issues with double vision, so I won't be rushing back to my ECP.


Likelenses 08 Oct 2016, 20:53

Kris

Unlike you,I am very myopic at -10.5 for each eye,and can only see 20/30 due to the minified distance images.

Four years ago at my exam.,my optometrist discovered a small muscle imbalance,and asked if I ever experienced any double vision.I said that after extended close work,that I did.

He said that I could benefit from some prism,but that he thought it would be better if I did not get it at this time.

Even though I am totally dependent on my minus lenses,he felt that if he gave me a prism,that it would most certainly need to be increased,and that if I can tolerate the slight double vision,that I would be better off taking more frequent breaks from close work.

He said as other here have pointed out,that when you begin to use prism lenses,that they most certainly need to be increased several times,and he was not able to predict how strong they ultimately would become.

So far the more frequent breaks seem to minimize the double vision,


Kris 07 Oct 2016, 17:53

I did the prism test a couple of times. With my current prism lenses I had 72cm between images at 3 meters. With my old lenses, without prism and with my current cyl prescription (I think they are 0.25 diopter stronger in both eyes) the distance between images was 130-135 cm at 3 meters. I tried to wear the old glasses for awhile today as, when I first put them on, I didn't think things were too bad. I managed to only wear them for a few minutes before the double vision and headache became too much. I didn't doubt it but I am definitely dependent on prism now.

I understand the issue with adapting to prism. I found my current lenses a little jarring when I first got them. Things were a little distorted and almost too 3D (if that makes sense). I've alway had issues adapting to new prescriptions, including a couple of weeks of seasickness when I first went full time with glasses, and again when I got progressives (not long after the initial glasses were prescribed).

Between my esotropia, hyperopia and impending (and now full blown) presbyopia I think I've had uncomfortable vision for a very long time. It took me a long time to even discuss my issues with double vision with my ECP and, even now, I'm not always sure what I should ignore and what I should report. Hearing others experiences with prism helps me to gauge where I'm at in managing my own issues.


Cactus Jack 07 Oct 2016, 13:15

Kris,

I think you need to do the test with full Sphere and Cylinder correction to keep the blurred images or compensation effort to focus from skewing the amount of displacement. If the glasses without prism have the approximate Sphere and Cylinder correct of your latest glasses, they should be OK. I think you can do the test with your latest 5/5/ BO (total 10) as long as you understand that the BO prism in your glasses will reduce the displacement by the appropriate amount for the distance to the target.

Most ECPs in the US will correct up to 50% of the measured prism. However, there is an adjustment process associated with prism correction that can cause some problems until your brain learns to deal with the displacement. Sometimes significant changes in prism correction can cause the symptoms of motion sickness or be difficult to tolerate both optically and psychologically. You mentioned the psychological aspects of prism in an earlier post about having to get your mind around the fact that you needed prism correction.

At some point, you will probably want to consult a Pediatric Ophthalmologist about muscle surgery to reduce the amount of prism you need to fuse images. Don't be put off by the name. Their primary practice is correcting Strabismus problems in children, but they also help adults.

C.


Kris 07 Oct 2016, 11:11

Cactus,

I did the prism test with an old pair of glasses without prism correction. Should I be doing it bare eyed? Is there a percentage of total prism needed that ECPs tend to aim for when prescribing prism? For example, eyes deviate by 40 dioptres, and will prescribe for 20% of total deviation.


Cactus Jack 07 Oct 2016, 07:51

Kris,

Typically, you should do the test without correction, but a person with Hyperopia probably needs to do the test with glasses. The reason for this is that there is a connection between the focus control system and the eye positioning system that causes the eyes to converge when they you try to focus. That can affect the results of the test. However, if you have prism correction, you need to make allowance for the prism in the glasses. Your total of 10 prism diopters Base Out, will compensate for 10 cm at 1 meter or 30 cm at 3 meters and your PLUS sphere will minimize the focus response, but there will probably still be some at 3 meters.

I suspect you have a very strong connection between your Focus Control System (FCS) and your Eye Positioning System (EPS). Almost any focusing effort will trigger the convergence response.

The Eye Positioning System has a number of external inputs in addition to the FCS inputs. In engineering terms, it is an Open Loop Servo System. Two very important inputs are the images delivered by your eyes. My personal observations are that the EPS tries to match sharp vertical edges using the Lateral (left and right) Muscles and sharp horizontal edges for the up and down muscles. If the images are not sharp and clear, it makes it more difficult to control the positioning muscles to keep the images fused. In most instances, if the image inputs are good, you really don't need full prism correction. All the the prisms have to do is get the images into a "capture range" and your EPS will do the rest, without conscious effort.

The exception to that occurs when the EPS simply cannot control the eye positioning muscles beyond a certain point as a result of crania nerve problems or damage or impairment to the brain functions that involve the EPS.

C.


Kris 06 Oct 2016, 21:39

Cactus,

I've done the prism test before. Originally, before I started wearing prism I was measuring images 75-80 cm apart when I stood 3 meters away. Once I started wearing prism I discovered that the images were 100-105 cm apart. I haven't measured, but I'd say they are at least 110-120 cm apart now (definitely farther, based on landmarks on the wall). I may get a chance to measure this weekend.

I was very reluctant to get prism in the first place and am still reluctant to go up more than I am at now. I sometimes find myself closing one eye if I'm tired or getting eye fatigue if I do close work for a long period of time. I spent a long time ignoring my double vision, and normalizing it. I find it hard now to know what I should accept as normal and when I should report symptoms and consider accepting an increase in prism. I find the testing subjective, especially, as you said as ECPs tend to want to prescribe as little prism as possible. My ECP didn't seem surprised at all when I had to go up for a third time in the 9 months since I first started wearing prism. He won't say what his expectations are, but indicated that he was waiting for me to admit I needed it when he first prescribed prism last year.

I find that since wearing prism, it is almost like my right eye is getting weaker. It used to only drift in when tired and would stay centered with my glasses off unlesss I really tried to focus on something close. Now it drifts in as soon as my glasses are off, and it is hard to get it to not turn in, even if I relax my eyes and let everything go blurry. Is it possible that it will turn in even more, the longer I wear prism?


Cactus Jack 06 Oct 2016, 19:55

Kris,

The color fringing goes with prism. Prisms bend light rays and the amount of bending is a function of the wavelength (color) of the light rays. You can also get color fringing with very strong lenses.

The reason for this gets a bit esoteric, but lenses are actually act like a very large number of infinitely thin prisms arranged in a circle. Plus lenses have the Apex of the prisms at the edge of the lens and the Base of the prism in the center. Minus lenses have their prisms arranged with the Apex in the center and the base at the edges.

You did not mention what lens material you got in your glasses, but you might try some CR-39, next time you order glasses. It has the best optical properties of all plastic lens materials.

It sounds like you have some Fatigue Esophoria. You could probably use more BO prism. Your eye positioning muscles are having to work to maintain fusion. Those muscles, like any other muscles get tired and you have trouble maintaining fusion when you are tired and let your concentration drift. When that happens, your eyes converge and you see double for distance. The reason you experience less tendency to converge for close work is that close work, itself, requires convergence, and that eases the positioning muscle work load.

Have you tried the Simple Prism Test that I posted on the Vision and Spex website?

You might find it interesting and perhaps a little scary. The test uses the optical principles codified by Sir Isaac Newton and it works very well if you follow the instructions. You my discover that you need more prism correction than you imagined. ECPs are typically very reluctant to prescribe full prism correction, for good reason. Fortunately, few people with Esophoria actually need full correction. That is one of the reasons ECPs prism increases are given, sparingly. There are a few others.

C.


Kris 06 Oct 2016, 15:34

Thanks Cactus,

I found that when I first got my current lenses images were quite distorted with the outer lines of objects appearing to bend in and with the colour effect I described before. I'm back to squares and rectangles looking like squares and rectangles but 5 months after getting these lenses, I'm still getting the strange colour effect (although more diminished).

I have to admit that I was really surprised to need as much prism as I do as quickly as I did. It seemed like others who've posted here moved up in their prism needs quite gradually. When I first posted here, I actually thought that I was a bit of a hypochondriac when it came to my eyes and that I likely only needed a minute amount of prism compared to others.

My vision has been comfortable with the 5BO, but I do notice my eyes working to stay fused. I don't let my eyes relax, but today when I did, I still had significant double vision when looking into the distance. I've never really seen double at near, it's more of an issue of the level of eye strain I experience to maintain fusion at near distances. If I do a lot of near work, I get eye fatigue and dry eyes. For now though, it's tolerable.

I've read a bit about other's experiences with prism, but would like to know how their experience compares to mine. How long has is taken people to stabilize in their prism needs?


Cactus Jack 05 Oct 2016, 07:30

Slit,

Probably not. More likely, the examiner is looking for Muscle Imbalance problems.

C.


Slit 05 Oct 2016, 01:53

Hi, I have seen some doctors do a test by holding a pen in front of the eyes of the patient, asking the patient to focus on it and then covering one eye, after that another etc.

Is this a test to identify hyperopia?


Cactus Jack 04 Oct 2016, 23:49

Kris,

Regarding the color fringing. One of the things prisms are used for is splitting the spectrum of white light into its component colors. Red is at one end of the spectrum and Blue is at the other.

If you cover one eye and look at a source of moderate White light, an outside window in a dim room, for example, you may notice that the blue fringe is on one side of the window and the red fringe is on the other side. Now, if you cover the other eye the Blue and Red fringes will be on opposite sides of the window. If you then look at the window with both eyes, the fringing will likely be substantially reduced.

Vision actually occurs in the brain and your brain will combine the images into a composite 3 D image an you may not notice any fringing at all.

I have worn much more than 5 BO in each eye for many years. I have noticed an extremely interesting phenomenon when I look at signs with Yellow LEDs. LEDs emit only one very pure (one wavelength) color of light. Yellow LEDs actually have two LEDs inside, very close to each other. One is Red and the other is Green. The result is Yellow for a person who does not wear prism. For me, I see a Red LED and a Green LED, That are far enough apart to appear as two. This is caused by the prism bending the Red light by a different amount than the Green light. When I look at a Yellow incandescent light, I only see one color, Yellow.

It is very likely that you will need more prism, but the important thing is to wear enough prism to not see double. The Eye Position Control System is amazing. It primarily uses the images from each eye to determine how to control the 3 muscle pairs on each eye to fuse the two images into one composite image. It does not have to have full prism correction to work. It only needs enough help to get the images close enough to be able to figure out what signals it needs to send to the muscles and fuse the images. It helps if the images are in comfortable focus. There is an interconnect between the Focus Control System and the Eye Position System that causes the eyes to converge with focusing effort. The strength of the interconnect can be very high in some people and focusing effort without their glasses can cause their eyes to converge or cross. That is probably what happens without your glasses.

Do not be too concerned about someone noticing that your eyes are slightly converged with your glasses. The amount of pupil displacement is really tiny, even with much more than 5 BO. Pupil displacement is about 0.1 mm per prism diopter. What people may notice is that the ouster edges of your glasses are a bit thicker than the inside edges, but they really have to be paying attention.

Let me know if I can be of more help.

C.


John S 04 Oct 2016, 22:44

Maxim, I don't know what your definition of very young is, but just because someone is young doesn't mean they have don't have a problem with accommodation. You must have seen a teenager with bifocals before. Just tonight I saw a ~14 year old kid in Walmart wearing bifocals. I would say his distance rx was -1.00/-0.25. Maybe a +1.50 add.

This past July, my friend's 12 year old son asked me if he could try my glasses. He put them on and said, I told my parents I needed glasses. I asked him why he thought he needed glasses. He said that he could see faraway fine, he just needed glasses for reading. Sometimes when he was reading he got light headed, and he couldn't see small text. I guess he wasn't persistent enough for his parents to believe that he needed glasses.

I told him to look through the bottom of my glasses at some really small print. I could tell he was trying to figure out how the progressives worked. His expression said everything. I could tell they really made a difference.

A few days later I brought over a reading vision card. He said he could make out the 20/25 line. But with my glasses he could easily read the bottom line. He wore them the rest of the evening. When I was getting ready to leave, he gave me back my glasses. He was really surprised when he took them off. He said everything was really blurry without them. I gave him the reading card. He tried as hard as he could to focus, but he said it didn't make any difference. He could just make out the 20/100 line. I told his parents he wasn't making up his vision problems. You need to take him to get glasses.

The next day he started wearing his Dad's progressives until he got glasses. They weren't strong enough, but they were better then nothing.

His rx was +0.75/+1.25 -0.75, add +1.75. He was already used to wearing his Dad's progressives, so he got progressives. He put them on, and they stayed on. He really likes them. He also got a single vision pair just for reading.

He is kind of small for his age. We were at a party, he had just gotten his glasses the day before. He has blue Nike semi-rimless frames. A lady said I like your son's glasses, they look good on him. His parents told her they had distance and reading in them. She said she really needed to get progressives too. She has to take her glasses off to read.

He his addicted to his tablet. If he is using it for more than a few minutes, he takes his progressives off and puts on his reading glasses. He puts on his reading glasses so he doesn't have to look down to see the screen. And he can see the whole screen without moving his head. He learned pretty fast.

After he had his glasses for a few weeks, he really got used to them. He said when he takes his glasses off his distance vision is a little blurry, but there is no way he can read anything. Everything close was a total blur. Wearing glasses is part of his life now. It doesn't bother him at all that he has to wear them. He actually likes wearing them.


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