Reducing more than advised

Many people working on reversing their myopia are confronted with the question on how much they should reduce their diopters by. Endmyopia recommends reducing ones spherical correction by 0.25 diopters at a time, why is that?

Endmyopia works by leaving you a little under-corrected for close-up and distance. This ensures that your eyes see a small amount of blur (more specifically, myopic defocus). It’s then necessary to clear up the remaining blur, to achieve clarity. Active Focus is the mechanism that enables your eyes and visual cortex to bridge that small gap between blur and clarity.

So what happens if you drop down by more than 0.25 diopters? Say, 0.5 diopters or more. The focal point ends up further away from the retina giving you a bigger blur challenge, reducing your diopter bubble and shrinking your distance to blur.

There are some notable downsides to this approach for you to consider:

  • If you are under corrected by too much it takes a lot more effort to get clarity on what you are looking at. The whole premise is that everything you do becomes a habit and many things take place subconsciously. This can only work if the discrepancy between clarity and blur/distorted vision is small. If you need to actively work on clarity because your diopter-bubble is too small a lot of stimulus is lost because you have to actively work your way through it and it takes much more time. With a smaller under-correction on the other hand it should be happening easier/semi-automatically. If you drop down by more than 0.25 diopters it is a serious possibility that you’re missing out on good stimulus. Jake explains this very clearly in these videos:
  • By having more myopic defocus it’s not only harder to achieve clarity in a static manner, but in motion it becomes next to impossible. Think about travelling by car, bike or just walking. While you are looking at something and there’s motion involved it’s a lot harder to achieve clarity, because what your are looking at is moving relative to your position. Your ciliary muscle has to adapt to this focal distance, Active Focus has to achieve the necessary clarity much faster and your visual cortex has to decode the data that comes in quicker to give you the proper clear vision. If you undercorrect too much this is hardly going to be possible, because it takes much more time and effort to achieve the desired clarity when motion is involved.

  • There is also a real risk of invoking blur adaptation. Blur adaptation means that your eyes and visual cortex become habituated to blur at a certain distance. Blur adaptation makes it pretty much impossible to improve because you aren’t working towards clarity anymore. Your visual system just accepts that there’s blur and there’s nothing that it can do to solve it. See Jake’s video on that here:

  • If the available light reduces it’s even harder to get that necessary stimulus. If you are under-corrected in too much of a manner you may very well be eliminating all the stimulus you could be getting in low light/dark conditions. Many EM students even increase their correction for these circumstances because of this.

All the things metioned above add up to one simple thing. You are reducing the stimulus you are giving your eyeballs if you drop your correction by too much. What you want is stimulus that is happening as much as possible and is manageable. If you reduce the stimulus you may even slow down your progress instead of speeding things up by reducing more.

A few exceptions that are sensible:

  • If reducing more than the average 0.25 diopters still brings you to 20/40 vision in less than ideal lighting conditions it may be a good choice for your new normalized.
  • If there’s some nice natural (sun)light available and you don’t have much problems achieving the clarity required for that important stimulus, it could be utilized properly. Keep in mind that this should be considered your “peak prescription”. It’s important to return to your normalized when appropriate. See more on that here:

Some good links:

Report from @MattE:
Great video on this matter by @MattE:
One local example:
And another one:


Member contributions to this topic can be added here:

  • Add your personal addition right here please

@FMR’s Comments:

  • Don’t do what I did (before this site existed, of course). I got scared into using near-strength (differential) glasses full time. I did so for many, many years. The result was little improvement during that 10+ year period, more strain, and blur adaptation. The blur adaptation resulted in my being unable to tolerate normalized glasses. I had to come up with a solution to reverse this, and I did, but it became a long-term process that will likely take one year when all is said and done. (If you’d like more details on that, please read my introduction post and my first update journal.)

From @tracylau:

  • Not using the correction you need may also tax your visual cortex to the point that it exacerbates fatigue. This is particularly if there’s a lot of blur and you’re failing to bring things into focus no matter how much you struggle. If you’re otherwise healthy you may not notice your visual system burning energy, but if you have anything else going on health-wise, reducing too much will be bad news.

from @Tii_Chen

  • Reducing too early occurs usually like this: Either you don’t understand the basics and make a mistake right at the beginning.
    But I think the more common scenario is like this: You read, understand, reduce. First differentials, first normalized - you are happy. Your first normalized can often be a quite big reduction - sometimes 0.75 diopters less! This is due to over correction before. Then you get your second differentials, second normalized - you may still be improving faster than 0.25/3-4 months, maybe until your 4tj normalized. This is due to your cilliary muscle relaxing.
    And here comes ego: oh wow, maybe I am one of the few exceptions who improve quicker - this is so cool! So now you have arrived at the normal improvement rate. But you are disappointed by your slow progress. You reduce again to force improvement - and then you are stuck and it’s happened!
    So please, keep in mind: first reductions can be quicker. But it will come to a halt, usually within 4-9 months!
Thanks to

@FMR, @tracylau and @Tii_Chen for their meaningful additions to this topic!


Not sure i understand the peak perscription.
Is it full minus correction without (or with aggressively lowered) astigmatism correction?
Do you add more minus to get to the circle of least confusion?

A peak prescription works like this:

You are feeling great, the sun is out, you had little close-up and are free of ciliary muscle spasm. In this scenario your normalized might give you too much clarity. Because of that extra clarity you aren’t getting much stimulus for your eyes to shorten (meaning there is hardly any myopic defocus). In this specific scenario you might switch to your next normalized for the time being to get some more stimulus and lock your improvement in.

This is independent of astigmatism. If you’re next normalized will have a reduction in cylinder correction then astigmatism plays a role. In most cases it’s just 0.25 diopters less again and you utilize your next normalized for a “peak” scenario to provide you with a nice extra challenge.

Now that I have your attention anyway, how about a nice profile pic.@itamar?


Thanks @Laurens
Done :blush:


If I’m right my current situation would be an example when a bigger reduction is ok, but let me know if I’m mistaken.

In short I found endmyopia 2,5 years ago, got a differential then 1 month later a normalized (which was about 20/50 on Snellen then). After it I mostly fell off the wagon because did not established active focus habit. Which also lead to settle a bit more stronger differential than needed. So for 2 years I just used the differential for close-up and normalized for distance (honestly, it just pains to use anything for close-up than differential).

Fast forward 1 month ago when I started working on AF again. Last week I also realized my differential is too strong (thanks to this forum!). Got a weaker one, my ciliary muscle popped and realized I now see 20/20 with my normalized indoor with only artificial lighting (with both eyes, 20/25 one by one). So I’m currently waiting for my eyes to adapt the new differential for 4 weeks but after I plan to reduce my normalized. And I think there is a high chance I will settle with 0.5 reduction because that will lead to about 20/50 on Snellen indoor. Fortunately I has glasses for both 0.25 and 0.5 reduction to test, so I will be able to just choose the best option.


Excellent thread! And the number one reason people screw up myopia improvement!

There are various theories that posit how the eye requires a certain level of clarity to adapt. (Most prominently, the theory based on longitudinal chromatic aberration.) So it’s NOT “more blur more stimulus”! If you deviate from the right amount of blur in either direction, you get less stimulus.

So, yea, this topic should be mandatory for anyone who starts with myopia improvement. I’ve read a lot of stories on how people failed, and I think reducing too quickly takes the top spot.

@halmadavid, if your current configuration made you improve to your current point, shouldn’t a 0.25 reduction from your current point allow you to improve again? Sounds to me like you can just repeat the same thing, starting from an equilibrium position.


While it would be totally cool if I could say I’m using only 3.0 dioptre glasses, but I think you are right :slight_smile: Especially since I already have the glasses at hand so it’s not even wasted money.

Also I’ve read a ton and ton of posts where people say they regret they reduced too much, I almost never saw posts where they regret they not reduced faster. I think there is a lesson to learn.


I may have a misunderstanding because I thought the 20/40 was in GOOD ambient lighting and I took this as inside with sunlight outside. Maybe I am still undercorrected. I also get eyestrain, red dry eyes, and pain around the eyes. possibly because I may be undercorrected? What do you think Laurens?

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I don’t think you are very off base here, that is not a huge amount of under-correction. However, it might be that it’s still a bit much for you, have you tried a previous normalized and see how that affected that strain, red/dry eyes and pain?

You’ve seen this already, but just a friendly bump to remind you that you are sticking to the teachings properly:


Yes thank you, in the past, using more correction felt better but at this point I will just tough it out until I am really ready to reduce. I a going to wait until 20/20 instead of 20/25 this time!


Brilliant post, congratulations Laurens
Definitely to hang it on my wall and not to make those mistakes…

By the way, my differentials are very nice on weekends, without any computer and with good outdoor walks…
Just every Monday, I have headaches, when I go back to office, either with normalizeds or differentials…


This has helped me alot! Thanks!

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I am surprised how I have read so much from the community, and yet have just found this topic now.


gotta dig into the archives @Brentkyle54 :upside_down_face:

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in the old days, we used to call this kind of activity “tomb digging” :rofl:,
and only the good stuff gets to be dug up.