I just made a post about astigmatism in another thread. I think it is more relavent here.
I suspect astigmatism is related to brain & Eye miscoordination rather than any problem with the eye (or size of eye or shape of eye). And the fixed focal plane of glasses really amplify this miscoordination.
Here, I think we need to understand the role of blur. When normal people (without glasses) see clearly, do they see no blur? Practically, they don’t see blur, but actually, they are ignoring large amounts of blur. Let me explain…
When a person focuses (zooms in) on a text, the text becomes more clearer but everything else in the background goes out of focus (i.e. it becomes blurred). So, ironically, you can see the clearest when your mind-eye are concentrating on a small part & everything else is blurrred. Normal people don’t notice the blur because their mind-eye coordination is so good that it constantly and quickly adjusts to what they see. (bringing the target into focus and blurring the background).
Now, if that mind-eye coordination is broken for some reason, then there is ghosting or variable blur(Travelling blur). Basically, the mind-eye are trying to work out a working relationship (what to bring into focus and what needs to be blurred & ignored). Now, add fixed focal plane glasses into this mix and the mind-eye coordination is completely broken.
So, how does Active Focus address the astigmatism?
Well, it is easy to zoom in on text and align a text (in case of ghosting). Basically, it allows the mind-eye to arrive at a working relationship. Remember, there are 2 eyes with 2 different seeing capabilities. Further, each eye can and does vary focal length. The brain has to put the differing quality images from these varying sources into a understandable format and then the mind (conscious part) reads it. Given, so many factors and variables, it is easy to see that miscoordination can develop, once in a while. The way to clear it is by just doing basic coordination in a familiar territory i.e. active focus on text.