I read a book by Oliver Sacks and he told a story of a person who got their eyesight at the age of 40 - having been blind since birth or very very young (I can't remember). Everyone thought this was such a wonderful thing and expected this guy to be eternally grateful. If I remember correctly, the guy ended up killing himself, as his brain was not wired for vision and "seeing" made no sense to him. Very sad story, but very interesting.
When I was a kid I had very bad eyesight, and no one knew. Until I was 10 I lived in a blurry world, trees were green blobs, and everything was muted and fuzzy. I never knew who was approaching me. I couldn't see the blackboard. ( I must have had very unobservant teachers!) Now I understand why I was so afraid of everything when I was a kid - I never knew what was coming next!
When I was 10 someone figured it out and I got glasses - I'll never forget the amazement of seeing that trees had actual leaves. That summer I went to Switerzerland to camp - to this day the Alps are, to me, crystal clear, etched against the sky.
Where am I going with these two stories? Well it's about learning to see, wiring your brain and learning new things. When I was a kid I always drew everything with a big dark line around it. Why? For me because I had to define things with edges, because I couldn't see. If I drew the world as I saw it, it would have been one big blob - and I think that was too scary for a kid so I defined everything with outlines. This starts here and ends here. OK, now I know what my limits are.
So just this morning I have been trying to draw a rock for EDM. I keep drawing outlines, even tho' I know that big black crayon edges don't exist. Suddenly I realized that I can leave behind the compulsion to outline my world, I can see now. I have to reteach my brain to NOT draw outlines, but to use shading. My brain can rewire and will.
If you can't see you can only draw what's inside your head. Learning to see is a very tough excercise.