diopter difference

I would like to hear your opinion, whether I am thinking correctly:

my situation is as follows: I’ve been wearing glasses since I was about 13 years old. My eyesight got worse very quickly, when I was about 18 it was: left -5.25/right -6.25. (My glasses were: left -5/right -6,) Then my eyesight didn’t change for about 15 years.
Two years ago, due to a job change that involved many hours in front of a computer my eyesight got worse: left eye -6/right eye -7. My eye doctor prescribed new glasses: left -5,5/right -6,25, as you see, my left eye was very underprescribed. One year passed and my left eye is now the same -6, but my right eye is now -7,75.

I found out about endmyopia in the spring, joined the course and started to realize that something is wrong with my glasses, my right eye shouldn’t be so underprescribed. I went to my eye doctor with the suggestion to increase the diopters in the glasses for my right eye. The doctor prescribed me new glasses: left -5,75/right -6,75 (because apparently you don’t put more than one diopter difference between the eyes in glasses).

I am not happy with that, because my right eye would still be very underprescribed and I fear that it’s just gotten lazy and will keep that way (apart from myopia my eyes are checked and are healthy). So, I am thinking about going to a different eye doctor and getting a prescription that is more like – left -5,75 diopters, right -7,5 diopters, so that my right eye also gets to see sharp and then, using endmyopia method, I can reduce the diopters. Am I thinking correctly? Or would it be enough, if I corrected right eye just to -6,75 diopters, as my eye doctor suggested?

I’ve finished the course and searched the forum but would really appreciate your opinion on this.
Many thanks!

How did you determine that?

Also, what line do you see on Snellen with your right eye only with your current glasses? And with both eyes?

thank you for your questions.
I went to my eye doctor last month, who told me that my real diopters are L: -6/R:-7,75.
With my current glasses that are L:-5,5D/R:-6,25D on 3m Snellen (with good lighting and during first half of day) I can see with my left eye 20/30 clearly, 20/25 with some blur, with my right eye everything is blur, but I can manage to see/guess 20/50 line. With both eyes I can see 20/25 line. I’ve also been told that my left eye is the dominant one.
I just think that I should increase the diopters for my right eye, so that I can do active focus with my right eye too. Because when I do active focus with both eyes, it seems that all the work is doing my left eye, when I do active focus with one eye, right eye sees just blur.
Thank you very much for your help.


1 Like

Are you measuring your own cm to blur, and if so, what do your measurements tell you?

Can’t emphasize enough how important it is to rely on your own analysis, including cm measurements and subjective Snellen experience.

My former practitioner used to over-prescribe one eye and under-prescribe the other. He never consulted me about it, just did it. Felt he was doing the right thing, I guess.

Suspect his rationale would have been that it would give me a good near and far vision experience. [Really liked the guy, and in a few years will probably go back and have a good conversation about all this.]

Never heard this before, was that a quote from your practitioner?

I never heard that before either. Clearly, neither has my optometrist or ophthalmologist since my diopter gap is 1.5 with my old glasses and 1.75 with the more recent ones.

Well, with kids, they often cover the strong eye and let the weaker one work. Maybe this opto believes that if the gap is increased over 1D than the weaker eye will become a lazy eye completely and this is their adult version for eye covering? But definitely a relatively unique approach in the world of optometry.
Also, interesting to see an opto who persistently underprescribes without overprescribing the other eye. What I heard of so far was more like bringing the eyes closer in the middle…

@leilasalma Tricky question what to do. If the gap is increased now that will have to be decreased later with all the added complexities of equalising. But if the underprescribed eye stopped trying completely then there may be benefit in increasing the gap. It will have to be a personal decision considering your own eyes, and experimenting with what works for you. If I decided for the increase I would surely not use the stronger glasses all the time, not even for distance vision, but intermittently, to trigger the eye to work but not to get used to it completely.

Thank you for your replies.

Yes, I measure my own cm to blur (not as often as I should, because with high myopia it’s really tricky, at least for me), and it’s 18cm left eye and 15cm right eye.

Yes, that is what my eye doctor said and she’s actually an ophthalmologist, not just an optometrist. So I used to trust her, and I’ve known her for like ten years and I like her as a person, but it seems I have to start thinking of my own :slight_smile: Well she explained that with a diopter difference more than 1D the brain will have difficulties to adjust the image from both eyes.

Thank you for your opinion. I think it would be wise for me to visit a different optometrist once again and see what he has to say, also to check my vision. I am leaning towards to increasing the diopters for my right eye, maybe not as much as I imagined (-7,5D), but definitely a bit more than that I have now (-6,25D).

Thanks again for your help, it will get easier with time, but now, in the beginning it takes a bit time and some advise to really make the right choice :slight_smile:

Well, I have heard something similar, but with a gap greater than 2 diopters. I’m sure it all depends on your own biology and visual cortex though.

Personally, I have no issues with binocular convergence or stereoacuity (depth perception) at a distance. My overall vision is still improved when I have both eyes open vs. just a single eye open. I do have a harder time trying to get my non-dominant eye to work with active focus though, since it has gotten a bit lazy and doesn’t try to focus as hard as my dominant eye does.

That said, because I have a larger diopter gap, I will need to start working on equalization earlier than others. Particularly given that it is recommended to have at least two binocular drops between each equalization step. Plus the equalizations will take longer, doubly so given I’ll be working on my non-dominant eye.

So yeah, it is better to not have a gap larger then 0.50D to begin with, but you gotta work with the cards you’re dealt. :slight_smile: