Blur adaptation is a dreaded concept because it ultimately hinders or stops (maybe even reverses) vision improvement progress. But as I see there are a lot of confusion about “blur adaptation” and many people misunderstand it. One the cause of this is that the “Clinical” Blur Adaptation (which you find in scientific discussions and papers) is different than “Endmyopia” Blur Adaptation. So let’s see which is what and what are their consequences.
Endmyopia Blur Adaptation
In short it means that you are just fine with the blur and don’t try to clear it with Active Focus. It’s the same “stimulus” (or rather the absence of stimulus) as when you are overprescribed and you don’t have blur. What you should understand is that the positive stimulus for eye vision which needs for improvement is not the present of blur. It’s the “struggle” against blur, which in this context means that you have some blur and you try to clear it, with more or less success. By that I mean even if you cannot clear the blur 100% it’s still positive stimulus. So if you have some blur and you can reduce it, then you are doing it right. Of course the “struggle” should not be too much, because otherwise you strain your eyes (and/or visual cortex). It should be a relaxing experience (but that’s more of a topic of Active Focus).
These are just analogies, but it’s like how you can improve your balance, or increase your muscles: you have to “struggle” a bit, but not too much or you just fall down or just injure your muscle.
Please note that while I use term “Active Focus” by that I mean any kind of method to clear or reduce blur. Call it “Active Focus”, “Passive Focus”, “Allowing Focus”, “Triangulation”, “Pushing Focus”, “Print Push”, “Pulling Focus”, whatever: if you have blur and you clear (some of) it, it’s the same thing. It also does not matter if you do it consciously, or if it’s automatic, without intent.
So again, Endmyopia Blur Adaptation means that you are fine with blur and don’t try to clear it. You just live in blur and if you want to see something clearly you just move closer or pull the thing physically closer. It does not necessarily means eye strain or bad feelings, though many times those are introduced too.
How can you combat Endmyopia Blur Adaptation? You can combat it by trying to clear the blur. Of course as a first step you have to have a method how you can clear it. Without finding this method you just increase the likelihood of getting (Endmyopia) Blur Adapted (that’s why you should not get normalized before finding AF, and also why you should not going without glasses before finding AF). Ultimately the goal is to get this “clear the blur” as a habit: you don’t do it consciously anymore, you eyes (or rather your brain) just do it automatically: as soon as it perceives blur, it tries to clear it (some call it “Automatic focus”, some call it “Passive focus”, but some understand different things on these terms, so never put too much emphases on phrases without understanding what that person mean by them).
Endmyopia Blur Adaptation is having blur but not try to clear it.
It is detrimental to the vision improvement progress, because it robs the eyes and the brain from positive stimulus.
Clinical Blur Adaptation
In scientific paper when they discuss about “blur adaptation” it means a different thing. In their experiments that the test subjects wear less correction than they need (or plus lenses) so they have blurry vision. They found that the subject’s vision gets better after some time of introducing this blur. So they introduce blur -> after some time the subjects see better -> which they are getting used to the blur -> the subject is adapted to blur, hence call it “blur adaptation”.
How does the subject’s vision improved? As far as I know it’s not discussed (or at least I could not find a paper about it). Maybe the subjects just find some rough active focus, maybe the brain is just getting a bit better analyse and identify blurry forms. But for our topic it does not really matter. What matters is that this Clinical Blur Adaptation does not mean that the subject don’t try to clear blur. This means the phenomena that after some time you introduce blur the vision adapts to it and get a bit better at navigating and identifying in it.
So the question if is this has a negative effect on vision improvement or not? We don’t have clear information, but in my opinion it doesn’t, or at least in itself it doesn’t. Of course getting used to blur can induce Endmyopia Blur Adaptation: you are just fine with the blur because you are more easily live with it. And that’s bad. But if for example you just getting too weak normalized / differential and you have more blur than you can clear, but you still try and try to clear it, and don’t introduce eye strain in the process, then I think you will progress just fine (but it rarely happens like that. Most likely too much blur hinders or stops the progress). Your quality of life may be lower though, and it’s not the amount of blur which provides stimulus, but the clearing it, so it won’t provide faster progress. Also it may induce detrimental (Endmyopia) Blur Adaptation. So in summary it’s still not recommended to live in blur.
It’s a process, which makes your vision better in blurry settings somehow (we don’t know currently how)
In itself it is not detrimental for vision improvement, but neither beneficial. Because of this, and because it makes you more susceptible to Endmyopia Blur Adaptation, eye strain, and because many people report negative effects on mood and general well-being when they live in blur, it is advised to avoid it.