"Checking" to see if your eyesight has improved

[ted]

I feel like this is a no-no. From what I've noticed, it seems to be a strain on the mind. Your checking to see if something is better, but not actually percieving the object with curiosity and imagination. Your are just looking at something to see if it's clearer. I'm not sure what to think about this totally, but it's been on my mind occasionally. What do, you all think?

[Nini]

So at first this may seem like you're paying attention to “too small” of an area of your vision and that it seems wrong to completely ignore your peripheral vision. That is an expected reaction. But this is the way it has to be done. Your brain will be relearning to use the visual data the way it's supposed to, and both your central and peripheral vision will be processed more efficiently.
...
Your central vision can therefore be practically defined as the only area from which you should expect clear details to come.
...
The area that you probably think of as your center of vision is really mostly your peripheral vision. That is to say, your central vision is smaller than you think.

These passages of David's text helped me to realize why "checking eyesight" has such a negative effect - although this bad habit is very persistent and difficult to get rid of, even when you understand, how it negatively affects your eyesight.
But understanding helps at least to call "oneself back", when you realize, you are "in it" again....

Davids clearly says, that you should expect clear details only from an area so unfamiliar small, that it seems "too small", in any case "smaller than you think".

Your brain has to "relearn" to use the visual data coming from this center in an different way than all the rest.
"Different" means: with the focus of attention, whereas the "rest" should be looked at "completely relaxed", in the same way, you look at a blank surface with nothing to to see on (which Bates suggests you should often do to relax your eyes).

In the center, there is only "space" enough for one clear information ("pixel") and the smaller the central focus, the clearer you see.
Once you start "checking eyesight", you automatically have to widen your attention - from "focus on the clearest information" to "focus on what is clear" + "what remains blurry" - in order to be able to make a comparison of both elements and "evaluate" your "status" of vision.

And on other 'fatal' point: you eyes are in constant movement, most of it unconscious saccadic movements.
To be able to get information of a "momentary status", you have to stop the movement momentarily - as if you would stop a film and cut out one single image as a "snapshot" in order to "analyze" it. So, this inevitably has the same effect as "starring".

[Nancy]

I agree with everything Nini (and David) said so well. What also occurs to me is the emotional component. I have often "tested" my vision and felt badly afterwards because it wasn't as good as I had hoped. This feels like the "glass half empty", observing again how my vision is not perfect (whatever that is) yet, rather than putting my attention on what I can see quite well.

[ted]

I'm kinda thinking that our thoughts are the triggers for our eyes. When you notice something it comes to your eyes, then to the mind, and then the mind directs the eyes movement. So maybe it's something messing up at the mind, that leads to blur. I'm thinking that the idea/thought to check the clarity of vision can be one such thought. It triggers a motor impulse in the eye that leads to decreased perception ability for some reason. What is seeing clear anyways? And how do we know what it's supposed to be like to see clearly, really, because we haven't ACTUALLY had clear vision for a very, very long time. But then again, maybe you can imagine that clarity somehow, which could guide you to getting there.

I dunno. Just rambling. And to qualify myself, I am merely theorizing all of this from personal experience. Take it all with a grain of salt.