My Theory about what active focus is, and arguments for and against it being necessary for improvement

I’ve thought a lot about active focus recently…

What is it?

Is it necessary for improvement?

Are there different levels of it?

Etc…


What do I think active focus is?

Well, I’m pretty sure it’s the lens of the eye changing shape!

How does it differ from “regular focus” or just “focus”?

For one thing, it’s dynamic, meaning you’re focusing not just at one distance and looking specifically at that distance, but at various objects at different distances over a period of time.

It’s also active in that you learn what makes good focus, and apply that to your vision. So, you can cause the eyes to focus, whereas maybe the image wasn’t focused before. It might take a little bit of “maneuvering” to do this.


A long time ago, I posted a topic asking whether people with perfect distance vision used active focus or not. Some of you probably thought I was nuts. I can’t find the topic at the moment.

Here’s the thing. I want to propose a two-level model of active focus…

Level 1 of active focus:
I think one level of active focus is probably due to recovery of normal focusing ability following the release of something similar to ciliary spasm, and recovery of motor skills required for focusing and converging at various distances. When people are fairly myopic or very myopic, and are overcorrected (which inevitably happened to many of us) the ciliary spasm becomes “embedded”. This is not just my word, but a word that Dr. Antonia Orfield used. The muscle is so locked that the lens has very little ability to change focus. I’ve seen hypotheses from others suggesting that maybe the lens or even a portion of it in some cases, gets stuck in the highly curved/close focus state chronically.

My own observations seem to support this idea…
After tons of close work and abusing my eyes, I feel a tightening sensation that it similar to, but not as intense as the feeling felt when the eyes are dilated and the ciliary muscle is paralyzed using drops. Who knows what the feeling is exactly, but it feels like a tight muscle. At the same time, ability to focus is diminished or suppressed.

When I was -5 D myopic, I didn’t always have this physical sensation back then, but that could have been because I was used to it. But what I did have was hardly any ability to focus at all. I wondered why my eyes hardly changed focus at all, and why I had difficulty focusing up close with my glasses on, and why the focus seemed to be fixed. I now think it was due to “embedded” ciliary spasm. It was so bad that I wondered if I had early presbyopia* or something. And to be candid, it didn’t get a whole lot better by not wearing glasses (during periods when I tried going cold turkey off lenses). We now know this was due to lack of sufficient stimulus.

But this has decreased substantially since then. My eyes can usually focus more properly now. I actually see focus changes (JNDs) occurring. So, I think the first level of active focus is just restoration of normal focusing that was perturbed by the lenses and maybe some bad habits (equally embedded) that were compounding it.

Second level:
But there also seems to be another level of active focus (which can even be forced to some degree). This one entails the ability to bring distant objects into sharper focus than theoretically should be possible. Clear flashes would fall into the same category.

My guess is that this level of active focus is a reduction of the curvature of the lens beyond the habitual resting state. I believe there are studies out there that deal with these concepts. I’ve read so many over the years that I can’t immediately recall specific ones, but I know I’ve come across ideas similar to this before.

Bates obviously had a version of active focus back then as well…it was called central fixation. The gist was that concentrating on an object would allow you to focus on it and your vision would sharpen for a bit. Of course, it’s arguable whether this was a result of level 1 or 2 active focus, or both, in my own theory.

One very interesting and highly relevant bit that I remember Bates saying was that straining to see at near would increase hyperopia at least temporarily, and that straining to see at distance would increase myopia temporarily. This is interesting, because it agrees with how myopia often starts for kids…straining while reading (or today, using a tablet or PC…which seem to accelerate the process even faster, I guess). Why? Modern optometry says hyperopic defocus in induced. Additionally, it would mean that the opposite of straining to see at distance would be active focus. This makes a lot of sense to me.

Moreover, any time I’ve tried active focus at near, I might get a temporary increase in clarity at near, but it tends to cause fatigue and produce lowered distance vision. If active focus is the opposite of “straining” the results would occur in a direction that agrees with all the theories/models (including Bates’s).

I think I’d personally modify Bates’s statements just a bit as follows (but still keeping the general ideas intact):

-Intentionally actively focusing in the positive direction increases myopia temporarily.

-Intentionally actively focusing in the negative direction temporarily decreases myopia.

So, there you have it. I’ve hit this idea of two levels of active focus from various perspectives, including using observations by Bates, and hyperopic defocus, and embedded ciliary spasm, to back them up.

Coming next: arguments both for and against active focusing being necessary for improving vision. I bet the astute members here can guess where I’m going to go with that. Hint: the two levels come into play. Everything above was background to set up my arguments.

*Presbyopia
-Yup, I’m going to bring this into the discussion eventually, too. Why do many myopic people who improve vision also improve their presbyopia (if they are at that age and have it)? I have some ideas as to why, and active focus is involved.

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Rest then bring it. Post > 20 chars

Looking forward to that one. I am measuring presbyopia as well.

First I wanted to refute the two level of active focus, but reading it through it make sense. But regardless you missed one point, which could be either a third level, but more like a parallel mechanism. You only talk about how the eye behaves on physical, mechanical level, but the vision is not just a mechanical process with lenses and refraction and absorbing photons, but vision have a mental component too. Well, the word “mental” maybe a bit too loaded at this point, many times associated with a kind of “wishful thinking” or “willpower” or at least some conscious thing. But I don’t mean that definition of mental, so maybe let’s call it a “processing” component. Because effectively that’s what our neuron system does (mostly in brain, but it starts in cell level in the retina): it gets two different signals from two different eyes (both in position and quality) and somehow constructs a unified image. And this process also contains an effects which can make the image more clear (so effectively can “focus” on the image), that’s why you see better with two eyes than one. And not just on the depth effect, but on the clarity part too. Honestly it was not really obvious for me with higher dioptre, but got really obvious since my latest reduction. Before that my stereoscopic vision was a bit improved version of my better eye. But now my stereoscopic vision much better than either eye separately, I definitely see details which I cannot see with separate eyes.
So the vision heavily involves a signal/image processing system which can also provide stimulus for the eye. And I’m pretty sure it do. Ultimately all living (or non living) tries to do it things with as minimum energy as possible. Taking your system we have the mechanical component where level 1 active focus is unavoidable, the level 2 active focus can be spared if the eye works correctly on mechanical level, and we have the processing component which partly also can be spared when the eye works correctly on mechanical level (you have to create the unified image, but you don’t need to improve it’s quality as much). So I think ultimately these two different stimulus provides the eye the signal to change, but we call all three mechanism as “active focus”.

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Very good points, and very much along my lines of thinking. The stereopsis is fascinating. With every increase in cm distance for my stronger eye (now 100cm) the contribution of my much weaker left eye with a cm distance ‘stuck’ at 18.5cm, provides more and more distance to blur for binocular vision (now an extra 14cm).

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I’ve thought for a while that there are “multiple levels” of active focus. It’s something like “semi-voluntary ciliary release” and “restoration of normal focusing” of the eye.

Good stuff.

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This matches somewhat with my experience since discovering EM (and earlier).
Earlier: looking for more than a few seconds at one point (focussed) -> eyes stinging, have to blink
Starting EM: tried to focus at one point for longer without blinking -> strained eye, released new floaters
Somewhat later: stinging comes only after multiple seconds, no further NEW floaters
Even later (now): it is very hard to stare long enough to cause any stinging - I can stare virtually for whole minutes without stinging
After all that: noticed slight improvement in distance vision on snellen chart and subjectively

Ciliary released?

agree with this part

This seems illogical. Jake says straining to see close-up (not at a distance) increases myopia. Straining while reading is close up not at a distance, so I don’t get what you’re saying

Fatigue maybe, but I haven’t noticed the lowered distance vision - maybe I have to test this

what are positive and negative direction for you?

yeah I think it also must be to do with active focus moving the lens more, keeping it more supple, whereas presbyopia results from hardening of the lens, so keeping it moving would logically counteract the hardening effect

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Exactly. I can’t think of why the tissues that make up the lens would naturally harden if they’re being exercised through their range of motion.

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Emmetropes also end up with presbyopia and often cataracts, so it is not only range of motion that is at play. Oxidation and the natural loss of small heat shock particles play a role in changing the lens, and probably several other factors still to be discovered. I have started looking at this in a separate thread on cataracts

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What do you mean by Intentionally actively focusing in the negative direction?

I think it means that you can also use active focus at your near points, that is the closest distance you can bring a piece of text to your uncorrected eye before it becomes blurry. Try to clear the blur. I do this to make sure I am not developing presbyopia as my myopia is reversing. So far my near points have not changed after a year on EM

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Thank you!

Addendum: I think the reason that everyone does not end up myopic or with staircase myopia, despite engaging in close work, is twofold:

  1. The focusing works correctly (or correctly enough) in emmetropes, low myopes, and stable myopes. If you’re focusing accurately at near, you’re avoiding a lot of hyperopic defocus.

  2. A lot of these people are either lucky that they were not given glasses/power increases, or they intentionally avoid being prescribed glasses or unnecessary increases in power. I’ve heard this one quite a bit. My own vision has been stable, as well, and I avoid unneeded power increases.

Good visual habits are also helpful.

is there meant to be a part 2? Did I miss something? I’d like to hear this bit.

I improved by multiple 0.25 reductions before ‘finding’ active focus. I’d say it was about 3 reductions and about 4-5 months in before finding it. I don’t feel like it inhibited by progress…

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Well, I went back and looked at my old prescriptions and while I have been seeing the ophthalmologist every year like clockwork, I hadn’t gotten a revised refraction in about 7 years. So I definitely fall into the second category.

During that time I used the same pair of glasses that I was prescribed with in 2013, but I learned to push them toward the tip of my nose when doing close-up work since they felt way too powerful to use otherwise. I also used my natural vision (looking over my glasses or taking them off) when doing anything very close, like using my phone.

When I got my most recent refraction done in September of this year, my new prescription was reduced from the one I had in 2013. They dropped 0.25 cyl in one eye, and 0.25 sph in the other eye. This was a cycloplegic refraction as well, so it should not include any accommodative (ciliary) spasm.

So there may have been a small increase in axial length over those 7 years, but if so, it was tiny. I am sure it would be much worse had I had been getting new glasses every year.

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I had only ~4 diopter at the start because I was always totally lazy to go to optometrists, so instead of yearly checking it was more like every 3-4 years.

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I think the cycloplegic refractions can be helpful in a lot of cases. Most of the drops used for dilation also produce varying levels of cycloplegia, so why wouldn’t an eye doctor take the extra few minutes (especially if they happen to have a slow day) to check vision again after the drops take effect (and do it before aiming the light in the eye to check the retina, because that bright light temporarily lowers the vision after exam)? Worst case, there’s no difference or it comes out worse. Just discard the results in that case. If it comes out lower by 0.25-0.5, run with it, and finalize that power. If it comes out lower by 0.75 or more, consult with the person about it, and maybe ask if they want computer glasses. I’m not an optometrist, but that’s what I would do. To me, if the cycloplegic is lower, it means there’s a potential danger of the power increasing over the next few years, especially if bad visual habits are used, or the power remains too high. I’ve also talked with optometrists who, in that case, split the difference between the power the patient “likes” and the (lower) cycloplegic result.

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Part 2a summary: Active focus is necessary for improvement.

Level 1 active focus is just a return of normal focusing that was lost due to a combination of incorrectly prescribed distance lenses, and their improper usage/bad visual habits. In other words, recovery of the default range (acommodative amplitude) that was locked up due to an acommodative/vergence issue imposed by lenses. The system is learning to un-compensate for the lens power error.

That error, if the focusing doesn’t work right, could do one of two things:

  1. Induce hyperopic defocus (and we all know where that tends to lead over time)
  2. Induce systematic compensation without an increase in myopia (more pseudomyopia/ciliary spasm, though)

The problem is, #2 probably leads to more of #1 as the cycle repeats, which might explain why people with higher myopia tend to have both issues. Also, as lens powers get higher (above -4, I would say), there are more effects from just the lenses themselves due to the optics, which I can’t even begin to think about now.

But if level 1 active focus represents a return to normal or semi-normal focusing ability, I would say it’s necessary for visual improvement. You can work through the arguments yourself, by applying this idea to the two cases above. Ask yourself what would happen to a person if the two cases existed or did not exist, singly or in combination. It’s a good thought exercise.

So that is an argument for active focus, that supports active focus being necessary for improvement. It also means that the lens change to the lower power that is no longer too strong can facilitate better active focus…it works both ways.

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It’s nice to see you back in action on the forum. I hope the new year is kinder to your eyes.

Your ideas about active focus are interesting, but how do they play out in people who are myopic but do not wear any correction and have not done so for many years? As usual I am the black swan (thorn in the flesh?) I paid more attention to what I could and couldn’t see, and instructed my brain to see more clearly. My brain responded by seeing more clearly, in drifts, which has built up to a reduction in myopia, even in the much weaker eye. Blinking and staring played only a little role in this, and I soon learned that neither was necessary. Nothing to do with lenses, reduced or otherwise.

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My own experience is that being undercorrected or not wearing glasses at all can lead to a softening of the reflexes that govern focusing response, as well as a faster buildup of ciliary spasm/less stamina. It seems like the focusing/convergence recalibrates to give the clearest image possible regardless of what you’re using for correction. So, in someone undercorrected, my guess is that the accommodation spends a lot of time focused near infinity, and tries to recalibrate the convergence, which is linked. This might explain why a lot of myopic people who are infrequent eyeglass wearers have convergence insufficiency when wearing glasses.

All speculation based on personal experience; you’d have to speak with an experienced behavioral optometrist to find out if this is true for most people.

It’s also possible that level 2 of active focus plays a role. More on what I think that is all about, soon.

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