If you're interested learning about accessibility —especially the broader issues outside of problems with vision — I'd strongly recommend having a look at http://rosenfeldmedia.com/books/a-web-for-everyone/

(Disclaimer: One of the authors is a friend so I may be a bit biased, but we did first encounter each other on discussions about accessibility in the 90's ;-)

The technical advice in it is mostly written for web folk, but the framework of accessibility/UX it places that advice in is pretty much applicable to anything.