For some reason tonight I remembered an episode of Mr Rogers I saw years ago in which he visited a blind artist who demonstrated how he worked. Don't know why it popped into my head but I was driven to find it on the internet...lo and behold I found the episode in question on the tribute artist of the guy himself (apparently he's dead now but I can't find any info about him online except the little that's on the website).
Anyway looking through some of his work on the site I was actually pretty amazed by how nice it looked. It's really amazing to consider that the guy who made these paintings had absolutely no vision at all, save that which existed in his mind.
http://cristdelmonico.com/index.php?content=delmonico.html Watch the Mr Rogers episode on the site, it's actually very relaxing
