New study on axial length decrease!

I’ve found this great new study that we’ve all been waiting for :grin: It was published in Nature research in April 2020 showing that “the human eye is capable of responding to the presence of blur by changing its axial length so that the retina moves towards the defocused image plane”. More precisely, they confirm that reducing axial length is possible. Also, they’ve found that after hyperopic defocus (wearing stronger glasses) it takes only 2 minutes for the axial length to increase, whereas for myopic defocus (wearing weaker glasses) it took 40 minutes for a significant decrease in the axial length. I think it’s only accessible through a university VPN but is free to share, so here’s a pdf :slight_smile: The time course of the onset and recovery of axial length changes in response to imposed defocus.pdf (1.3 MB)


It was linked to a previous topic, but it did not gain traction ( Month-aged paper about defocus and response ), I found this paper really interesting, I think I will just move my comments from there and I hope more people will notice this paper this time :smiley:


I think similar studies have been done before. What we now really need is for this to be tested on myopes with permanent mild myopic defocus, to see if the axial shortening persists over time. There will be very little motivation for such an expensive study to be undertaken.


I think it’s a really interesting part:

Approximately 2 minutes after the removal of hyperopic defocus, the elongated eye recovered significantly by 63% (p = 0.010). The eye then continued to shorten rapidly over the next 20 minutes, recovering by 91% at the end of 20 minutes (mean difference of +1 ± 10 μm relative to the baseline, p > 0.05).

Effectively it means for us that even if you introduce hyperopic defocus during close-up, about 20+ minutes break is enough to make the negative effects vanish. Of course here the defocus part only lasted for 60 minutes, so most likely for longer close-up time, longer break is needed. If it’s anything near to linear then it can align pretty well with @jakey’s recommendation of 1 hour of distance break after 3 hours of close-up time (I also remember 20 minutes after 1 hour, but I cannot find it).

Also it confirms what was known from chicks and from suggested for humans, that the eye responds better to myopic defocus than for hyperopic:

After 20 minutes of clear vision, on average the eye recovered by 50% from myopic defocus while it recovered by 90% from hyperopic defocus.

Which is good for us, because it means that you need relatively less amount of distance vision to counteract and even improve the negative effects of close-up.

Also they confirm’s @jakey’s another advice that you should have about 1 hour of continuous distance vision every day for improvement:

We found a continuous exposure of a minimum of 40 minutes was required for myopic defocus to have a significant effect on axial length reduction in human eyes.


Aha, I have also missed it, thanks for pointing it out :smiley:


Also it confirms what was known from chicks and from suggested for humans, that the eye responds greater to myopic defocus than for hyperopic

Yes, I’ve found it through the link to the list of papers citing the one from 10 years ago done for humans :smiley:

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But this does not explain why after 30 years of almost permanent myopic defocus, and virtually no hyperopic defocus, my eyes did not shorten. So for permanent axial shortening a stimulus other than myopic defocus is required - AF.


This is a nice find. I’m definitely putting it in my Share This folder for people who give me side-eye when I tell them I’m reducing my myopia.


Made a wee start on the Clinical Studies wiki page. Also linked to this page on the main page. If anyone has the time it’s easy to add some links. Studies are for everyone, not just @kem’s side-eyed friends.


My friends will barely read a paper, much less a whole wiki. But wiki, yeah! Good idea!

I personally love it.

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Indeed; I actually like Jake’s analogy that to improve, we are replaying the progress of our myopia progress backwards. Interestingly enough, the hyperopic defocus that caused progressive myopia was not passive; we did push through the discomfort (in my case, on optometrist advice, that it would make my headaches go away hahaha…). I feel that pushing through the discomfort of working up close with minus lenses is analogous to Active Focus. It is harder to reproduce that same thing at a distance because it is likely much less engaging than whatever is happening on a screen, which is why we need to consciously “find” active focus, and why we see that some people take months to achieve it while for some people it is like second nature.

So this study shows that axial length changes both ways temporarily by introducing defocus. But what causes semi-permanent change might very well be the chronic stimulus. And for any chronic stimulus to happen it needs to be sustainable; you wouldn’t see anyone reading a book while overcorrected by over 3 diopters, all day every day; they are unlikely to keep doing it with all the headaches and blur, they are bound to take a break long enough for their eyes to go back to normal. But half a diopter of overcorrection seems more doable. They make you wear more correction than you need without it causing more blur, and they make you wear it all the time except when you are sleeping. Add to that the fact that screens are engaging and that you can forget discomfort in them and maybe that’s what really causes the change to become permanent.
If that theory is correct, then active focus and constant myopic defocus should also shorten the eye semi-permanently (oversimplifying of course, we know there are other reactions to stimulus and we probably don’t know half of them). Ditching the glasses is more sustainable than going overcorrected because the natural focal plane is comfortable in many ways. Though whether or not it allows for constant active focus probably depends on the person and their lifestyle.


I completely agree with this. Make the temporarily shorter axial length your “new normal” and then stimulus from there!


There’s an old interview out there with a Russian KGB defector talking about how to brainwash and demoralize a population.

Not reposting here since it’s all quite political tangents and topics I generally like to stay away form. What struck me and stuck in my head, him talking with great confidence about how ‘facts don’t matter to people anymore’ at a certain point.

I feel this way about all of these studies.

They are fascinating and yes absolutely we want to keep reading and sharing. At the same time though I’ve never once sent one of these to somebody claiming to be wanting proof, and them ever reading it and then being more open to these ideas. It’s always just finding some (real or imagined) flaw in the study and maintaining their established beliefs.

It’s quite weirdly, part of ideology. “No, you can’t reverse myopia, and I don’t care what proof you find to the contrary.”

Good news though is that we don’t need them as intermediaries anymore, we can just connect directly and share our experiences and interesting studies and things (till YouTube censors us, anyway). :joy:


If that’s the interview I’m thinking of, that was quite interesting. And it was an old interview with him (Yuri Bezmenov). He talked about the brainwashing steps they followed and how successful they were and how quickly. But perhaps you were looking at a different interview.


If you have a link to this interview, could you sent it to me in PM? :slight_smile:

We also have the Conformity experiment:,-By%20Saul%20McLeod&text=Asch%20(1951)%20devised%20what%20is,was%20due%20to%20group%20pressure.
In short, put a person into the group, make every other person in the group give wrong answer, and the subject will also give wrong answer almost regardless how sure they are. In some cases they can even convince themselves that is really the good answer.

It’s also hard when you really try to get information from these studies (so when you dig for new information and not looking for studies to support something), because they really almost always have some flaws*. If nothing else then the test scenario is a bit hard to apply to real life, which may or may not a problem. Also you can practically find a study for everything and for its exact opposite :slight_smile:

*I had a lot of debate in lchf communities and looked up and linked a lot of studies and I was always hoping that someone points out the flaws in the study I linked (to support my own views), but almost always I got disappointed :smiley: People just usually skip them or say “whatever”.


You should really team up with that guy and do regular axial length measurements through your progress :slight_smile: It would be a great data point.

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I don’t know what’s the distance, but it does not have to be done frequently, because AL does not change too fast. So if for example every 6 months you could do a measurement that would be more then enough to prove the improvement. But even do a measurement now, and another one when you are 20/20 would be a great data point, because we don’t really have those :slight_smile:


You’re right, I will try to achieve this colab, would be really great to have an opthalmologist on board :slight_smile:


It seems not, and this is a pity as surely EM has been going for long enough for us to have some data points on this. From a very early blog post written by Alex, it seems that EM participants were discouraged from wasting money on measuring axial length, as he believed that axial length was not relevant. I think EM has changed its position on this, and I do think some of the older posts should be removed, as this one certainly confused me when I first read it. It was you who pointed out to me that it was written by Alex, and not by Jake.


Cherry picking, confirmation bias, and accusations of same at the person with the suggested information.

Just like being vegan. The truth is out there.