Author Topic: What prescription will help a weaker eye grow faster?  (Read 2792 times)

Offline graeme

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What prescription will help a weaker eye grow faster?
« on: September 14, 2014, 04:45:37 PM »
I have some good news. I went from -3.5/-2 to -3/-1.75. I undercorrected my lenses by 0.5 diopters, and looked in the distance when walking. At the computer I used some -0.75/0 lenses to let my left eye see.

I want to help my left eye recover faster, since it's weakest. Am I correct to think that undercorrecting my right eye further will make the left eye dominant and help it recover faster?

I was planning to use: -2.5/-1 for distance, -0.5/+0.5 for computer.

My worry is that the eyes will adjust up to the space allowed by the undercorrection and this may actually help my right eye more by giving more space. Which hypothesis is correct?

p.s. Some have suggested using a Snellen. I've tried this, but my apartment doesn't easily let me do this, and my left eye is weak enough that I can't get measures. I'm going to periodically measure my prescription with optometrists so I get an outside view of my progress.


Offline OtisBrown

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Re: What prescription will help a weaker eye grow faster?
« Reply #1 on: September 14, 2014, 05:22:49 PM »
Hi Graeme,

I know that an OD wants to help you - but sometime it is far better that you do  your own checking.  If you can under-correct, you might be able to read the 20/40 line at 10 feet.  Here is how to modify the 20 foot chart - for 10 feet.

https://www.youtube.com/watch?v=WYw5TFoLpIY

I think excessive prescriptions create excessive difference between the two eyes.  The sooner you "equalize" what you look at, the sooner the difference will reduce.  But I appreciate that, for now, you will want to use a weak minus on the other eye.

I would never discount the need to verify your visual acuity - with a bright light on  your own Snellen.  That can give you confidence in your improvement work.

Further, you can judge and obtain the exact and weakest lens you need for distance.  I seems that now, you can work at your computer with no lens on.  Getting rid of any lens for near is a big step forward.

But take the time, down-load the Snellen, and mark it for 10 feet.  It is a confidence builder.



I have some good news. I went from -3.5/-2 to -3/-1.75. I undercorrected my lenses by 0.5 diopters, and looked in the distance when walking. At the computer I used some -0.75/0 lenses to let my left eye see.

I want to help my left eye recover faster, since it's weakest. Am I correct to think that undercorrecting my right eye further will make the left eye dominant and help it recover faster?

I was planning to use: -2.5/-1 for distance, -0.5/+0.5 for computer.

My worry is that the eyes will adjust up to the space allowed by the undercorrection and this may actually help my right eye more by giving more space. Which hypothesis is correct?

p.s. Some have suggested using a Snellen. I've tried this, but my apartment doesn't easily let me do this, and my left eye is weak enough that I can't get measures. I'm going to periodically measure my prescription with optometrists so I get an outside view of my progress.

Offline Alex_Myopic

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Re: What prescription will help a weaker eye grow faster?
« Reply #2 on: September 15, 2014, 08:36:21 AM »
I believe with patching you can improve the weakest eye with greater rate and if this happens you don't have to undercorrect unequally. With your method even if you achieve to have the weakest eye dominant this doesn't necessarily leads to grater rate of improvement in the dominant (with lens) eye.

Offline graeme

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Re: What prescription will help a weaker eye grow faster?
« Reply #3 on: September 15, 2014, 12:22:42 PM »
I believe with patching you can improve the weakest eye with greater rate and if this happens you don't have to undercorrect unequally. With your method even if you achieve to have the weakest eye dominant this doesn't necessarily leads to grater rate of improvement in the dominant (with lens) eye.

That may be, but I won't be walking around town with a patch. So far with my "lazy man's" method above I was still able to make good progress in a short time. If this method stalls I'll try stuff like patching, and I may try patching at the computer.

But what level of undercorrection do you think is best for distance viewing?

1. Equal undercorrection on both eyes
2. Less correction on the strong eye, leaving my weak left eye dominant?

Edit: It is interesting that with the equal method I had before, my left eye improved 0.5, while my right just 0.25. But my data is just one, so I can't draw conclusions.
« Last Edit: September 15, 2014, 12:24:27 PM by graeme »

Offline Alex_Myopic

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Re: What prescription will help a weaker eye grow faster?
« Reply #4 on: September 16, 2014, 07:45:17 AM »
I believe that the same undercorrection is better. If you make one eye dominant with the lens maybe the rate of its improvement will decrease and maybe the brain will depend more on this eye and not try to improve the more undercorrected.

Offline graeme

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Re: What prescription will help a weaker eye grow faster?
« Reply #5 on: September 17, 2014, 07:51:04 AM »
I believe that the same undercorrection is better. If you make one eye dominant with the lens maybe the rate of its improvement will decrease and maybe the brain will depend more on this eye and not try to improve the more undercorrected.

That's actually what I'm trying to do, if I understand you correctly. I WANT the strong eye (more undercorrected) to stay the same while my left eye improves. Ideally I'd experience this change:

-3/-1.75 --> -2.5/-1.75

And then repeat.

Because once my right eye gets down to -0, then it seems like it will be harder to make progress in my left, as I can no longer undercorrect the right for distance vision. So won't my right eye become dominant and block further progress in the left?

I'm worried about a -1/-0 scenario.

Offline warnbd

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Re: What prescription will help a weaker eye grow faster?
« Reply #6 on: September 17, 2014, 09:21:29 AM »
I'm worried about a -1/-0 scenario.

Hi Graeme,

I guess I will weigh in on this, I have a similar unequal eye strength issue and have been at this for the last 8 months.  I have been getting progress at a rate of .25 or more diopter per month on both eyes.  I have found that for me I want the blur plane for both eyes to be  at the same distance.  When they are not, even by .25 diopter difference, I find the one eye that is not corrected enough gets extra stress and strain as it tries to come into focus and fails.  This is because as you push the print out to D2 distance, this distance is the one whose more corrected eye has the start of blur.

I would suggest to make the under-correction the same for both eyes, and if you want, patch the opposite eye that you want to "catch up" with the other some of the time.  Then at each time you are ready for another set glasses, re-evaluate your eye relative status.  If one eye has been improving more, re-figure for equal under-correction.  For me, I started out with about a 1.25 diopter difference, and now it is approaching .75 difference without patching or creative prescription. A natural process of equalizing may occur over time.  For me, I want to get at least one eye to 20/40 as fast as possible, not wasting time waiting for more equalization. 

Now, if you do arrive at -1.0, 0 state, just continue with new glasses that continue the process for the weaker eye, with under-correction in only the one eye.  There are people that pay out for Lasik to purposely have unequal eye levels in order to have one eye better at distance, and the other eye set up for close work.

Regards,  warnbd

Offline graeme

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Re: What prescription will help a weaker eye grow faster?
« Reply #7 on: September 17, 2014, 05:56:50 PM »
Thanks. Have you been doing near work at the edge of blur?

I've mostly been doing distance work. That was why I was concerned about inequality: I'd have to wear a patch outside.

But if I get to -1/0 I can probably just work patched at the computer for a while with no glasses or minus lenses and help my left eye that way.

Edit: I decided to go with same undercorrection. For near work, that means I'll be moving to -0.5/+0.25. Is there any issue with combining minus and plus?
« Last Edit: September 17, 2014, 06:07:09 PM by graeme »

Offline caimanjosh

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Re: What prescription will help a weaker eye grow faster?
« Reply #8 on: October 13, 2014, 10:52:08 AM »
I'd be interested to hear how your progress goes with this.  As it happens, I'm actually in that -1/0 scenario (right eye is 20/20 now, but left eye still around -.75 or -1).  I've been patching the right eye and training the left only for about 6 weeks, but I'm not liking it much -- it feels a lot more taxing to push print in monocular mode.  (And there's the psychological block of knowing my right eye might get a bit weaker in the meantime, though it hasn't deteriorated much yet.)  I'm thinking of laying off the patching approach soon and trying some +4 L / +4.5 R (or maybe +4.5 L / +5 R) lenses instead.  I worry, though, that the dominant eye will receive all the stimulation and the left will just relax and do nothing.  I kind of think this is what happens when I walk around now -- I don't wear any glasses, and my brain's image comes from the clear right eye, rather than the slightly blurry left. 
Anyways, please do post your progress!