I’ve thought a lot about active focus recently…
What is it?
Is it necessary for improvement?
Are there different levels of it?
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.
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.
-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.