🎥 OCULAR DOMINANCE: Why Your Eyes Each Don't See The Same o_0

Why it matters, how to address it, where to find the gold at the end of the rainbow. All in this and more in the most high production value expose of an awesome explainings-of-all-teh-stuffs, video.



I left out a pretty important part, which is to reduce diopters only once the non-dominant eye has also improved fully. Both eyes are a team, let them work together.


Ok I gotta start measuring my cms again. I’ve reduced my diopter ratio from an initial 3.5 to 2.75. Active focusing with this ratio is easier than a 2.5 ratio (learnt from trial and error) so will stick with this for now before attempting any more diopter ratio reductions.

Mainstream optometry is like some gym bro going “You’re right-handed, so use less weight on the left!”

Thanks, as always, for bringing attention to these topics! I think it was one of your videos where I first noticed the term “ocular dominance”, and it all started making sense from there. I have at least two friends who are in a bad place from this shit: one has many diopters of asymmetry, the other cannot reach full acuity on one eye anymore, no matter the correction, and has both myopia and strong astigmatism on it.

IMO, the reason for dominance is likely a convergence property of the brain. When there is a good signal from one eye, the other can be used mostly for depth and minor things without much loss in overall acuity, so the brain doesn’t necessarily get stimulus to further resolve the non-dominant eye’s signal. It could be the same mechanism that causes amblyopia, and maybe also handedness, jumping leg dominance, and so forth.

For a few months, I have made it a habit to wink my less myopic eye shut every now and then. Lo and behold, I now can’t even tell which eye is dominant anymore. The “look through a frame of your hands” test ended up inconclusive, and blocking one eye only makes a difference if my left eye is beyond its maximum focusing range.

Patching could work via the same effect, reducing an unhealthy level of dominance that has been covered up by years of asymmetric lens use. That would also explain why you don’t need a lot of it, but need to do it regularly for a while: brain changes don’t require much exposure time, but they benefit greatly from repetition with sleep cycles in between.

If even small levels of amblyopia cause focusing laziness, and this in turn interferes with distance calibration enough to accelerate myopia progression, it all comes full circle. The opticians can then ramp up the difference between the eyes indefinitely, causing these crazy glasses where one lens is twice as heavy as the other.

It all becomes so logical and consistent once you get away from the crazy dogma of mainstream optometry!


Thanks for this video, Jake. Over the last year I have read through much of the blog, but then end up with ciliary spams from reading too much. I am limiting my computer reading as much as possible, so really appreciate these videos. I tried making a video, but don’t really know what to say. I thought I was improving and lowered my “prescription” 3 times over the last year, but according to my eye doctor, the only improvement was the astigmatism. I seem to be “stuck” now at -3/-3.5, with my measurements of both cm and Snellen chart fluctuating daily. Is that normal?

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= “brachial dominance”? :wink:

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Hmm, I’m not quite sure I fully understand the ocular dominance thing and its implications.
I understand ‘ocular dominance’ as something like ‘the eye whose image my brain prefers over the other eye’s image’.
If I use a ‘dominant eye test’ (e. g. https://www.allaboutvision.com/video/dominant-eye.htm), my dominant eye would clearly be the right eye.
However that is also my ‘weaker’ eye (the one with the higher diopter value). Logically, it would make a lot more sense to me if it was the other way round; it seems a bit odd that the brain would prefer the naturally blurrier image over the clearer one. However, I don’t even seem to be an exception in that respect (‘ocular dominance’ in wikipedia links a study that suggests this to be quite ‘normal’ behavior; google scholar suggests somewhat mixed findings).
I’m not sure if the correlation (or non-correlation) between visual acuity and ocular dominance makes a difference in the decision when to start working on the difference between the two eyes. Maybe it just boils down to ‘whatever feels the right way to go’ at a certain point…

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Same here, my dominant eye (the right one) is the slightly more myopic one, always been. One theory I remember seeing is that the dominant eye tends to have more ciliary spasm simply because it works harder.

At any rate, diopters and Snellen only provide a marginally narrow picture about your visual ability. The dominant eye is the more responsive one, and in the real world, ability to focus fast, track movement precisely etc are probably more important than absolute clarity. At least for me, the non-dominant eye is very similarly clumsier and slower as my left, “non-dominant” hand is compared to the right one.


Bridge, it’s not like the more myopic eye is always blurrier. That’s only for distance vision. If you got myopic from a whole lot of near work, your dominant eye didn’t have any disadvantage there.

Relatively small asymmetry could be just random, from overzealous optometrists. Intuitively, you should be at an advantage for equalizing, since your dominant eye is less likely to become lazy from a little blur.


My left eye is dominant and has always gotten a prescription that is 0.25 diopters stronger.

When I use binocular vision and see clearly, if I cover my dominant eye, then my right eye appears a little blurry. However, I can easily focus bring the right eye into focus while the left is covered.
However, I can’t do it in the reverse order. I can’t bring the right eye into focus unless the left eye is already in focus. It seems the dominant eye must lead first and focus first.

Jake has said the dominant eye is more responsive to blur stimulus and can improve more quickly than the non-dominant eye in a video which unfortunately came out right after I already ordered my new glasses in the story below.

I recently discovered my dominant eye had been making twice as much vision improvement across 2 pairs of glasses as the non-dominant eye. While on my 3rd pair, I plateaued and finally measured each eye individually to discover my right eye had fallen woefully behind. Only on the rare occasion when both eyes were in focus was my vision crystal clear.

Then when I mistakenly tried to boost the right eye power by just 0.25 diopters, I simply could not bring distance into focus. I knew a change in power ratio between the eyes was a risk but I figured it wasn’t a bad idea to equalise the prescription in each eye and it was only 0.25 diopters.
I could focus with my differentials but I suspect near vision is just easier for the myopic. After just 1 week, when I reverted back to my previous normalised glasses, to my utter surprise, my non-dominant right eye was the clear eye and the dominant eye which had always been the clear eye, was now blurry! I think this was because my visual cortex started to favor input from the non-dominant eye over the dominant eye when the non-dominant lens had been boosted in power. You really do see with your brain. I continued wearing the differentials, but stopped after 1 month because even though I could see clearly for close work, the different power ratio between the differentials and the normalised were hampering my distance improvement.

Anyway, the lesson I learned is clear binocular vision doesn’t mean both eyes are seeing clearly so I should not move to the next reduced prescription until the non-dominant eye is clear too. Also, don’t change the power ratio unless you have nothing else left to improve.


This is very similar to my experience. And the same happened when I tried to equalize (before EM), tried to boost the non dominant to equalize, and my brain ended up disregarding my dominant.
So, apparently having the dominant eye with higher correction is not so uncommon after all. I wonder, for those that have this, did the ratio change much over the years or did it stay the same? I’ve had 0.25 difference since my first prescription, and it increased only with my last one, but my left ciliary was spasming like crazy due to way too excessive close upat that time, and eventually it went back to the same 0.25 difference again, but people that are corrected the other way around often experience their diopter gap getting larger at each prescription, just like presented by Jake. From Myst and Panu’s words I seem to understand that their gap isn’t very high either, I wonder if it’s a coincidence or not.

Also, I always noticed that the blur of my (dominant) left eye is not the same as my right. Like, left eye is a bit more double vision-y while the left is more plain blur. I always noticed this way before getting into vision stuff. Anyone noticing similar differences?

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Well, for me (dominant eye slightly lower in diopters), there has been a change in the ratio. However, I am not sure, how accurate that prescription was. I usually had 0.25 difference, the prescription in question gave me a full diopter difference between left and right.
By measuring centimeters and playing around with a test lens kit, I now get to 0.25-0.50 difference again. The weird prescription had also indicated a much higher astigmatism value in both eyes as well as changed the axis in both eyes.
So I’m really not sure, if there has ever been a true change in the ratio between my eyes. I’m somewhat inclined to follow Panu in the assumption that the dominant eye experiences more ciliary muscle spasm. That would make a lot of sense since that prescription was shortly after I experienced some cornea ablation in my left eye (dry eyes) which may have led to the right eye ‘taking over’ even more.
I’m really curious how all of this will fall into place once I really get started with endmyopia. The last couple of years I had basically just pretty mindlessly reduced diopter in my glasses - with as far as I can tell neither particularly good nor bad effects - apart from the fact that getting used to blur ultimately is not all that great :stuck_out_tongue:

Hi Annarosa,

Thank you for your feedback :slight_smile:
I have the same phenomenon than you… You said " tried to boost the non dominant to equalize, and my brain ended up disregarding my dominant".

Can you please explain how you did that, to boost the non dominant eye ?
Many Thanks :grin:
Best Regards

That reminds me of something: one time, when I still was a little sheep, long before becoming an enlightened kitteh due to finding the beard, I was at the optometrist. Actually the one I still go to. The one that was amazed that my astigmatism had changed, because according to him, you’ born with that. So that very same person suggested to ‘change the axis a little bit in your glasses and let’s see if that works better for you ‘
So, even though he doesn’t believe in changing astigmatism, he’s still playing around with my astigmatism axis -how weird is that? What a profession is that, really…
I don’t even remember why exactly. I do remember how annoying the eye test is when it’s about astigmatism: I just can’t say which lenses are better, because I seem to see some kind of difference, but diesen make it significantly better or worse. So hey, let’s change the axis.
Weird thing, really.
Sorry it’s off topic, but came to my mind when reading your comment…

Also, my prescription history, as far as I have it, shows a funny up and down in ratio - both eyes the same till 0,5 for whatever reason…

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I simply increased its prescription by 0.25 to make it equal to the other. It was before EndMyopia, when I was following another method, and it was a time when I stupidly monkey’d with lenses. The 0.25 increase gave my non dominant too much advantage and my dominant eye couldn’t improve.


I believe eye dominance is kinda necessary to see “normally”. The smartphone cameras use to have 2 cameras, at different Mega pixels each, just to make more beautiful photos. Just a thought…

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Okay so I decided to try and equalize the differential bc I get similar cm measurements on some days. I’m getting the following so far: consistent clarity on dominant eye
Coming in and out of focus on non dominant eye

And I’ve seen this happen on a day where the eyes started out similar vs Snellen and cm measurements.

My next immediate step is prolly get the non dominant eye cleared medically for other reasons but beyond that are there any tips for successfully encouraging the non dominant eye to hold that focus?

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Time. And binocular active focus. And patience. And if need be, a tiny bit of occasional patching.


@jakey what exactly is binocular active focus? Attempting to clear with both eyes simultaneously? Another interesting thing I’m running into is it’s really obvious when one eye is seeing clearly and the other isn’t when reading a computer using contacts+readers. It’s really hard to tell without closing an eye when reading books without any lenses under nice lighting. Then it’s like I just see the image from the dominant eye no ghosts or impressions that would indicate partial blur

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Yup that’s exactly what it is.

Lol I guess I’m doing a form of patching …on non dominant eyevwith wet cloths as part of a medical treatment Also how should reductions/choices go once were at the point of going without correction for some activities? It’s according to the dominant eye right? And ready to reduce is 2 weeks of clear stable binocular vision? And how should full correction go? 20/20 on weaker eye in relevant lighting ?