There are screen readers (text to speech generators), braille displays.

I don't know what is the status for fingerreader ( http://fluid.media.mit.edu/projects/fingerreader )

Also have a look at HandyDV Linux (https://handylinux.org/index-en.html). The aim is to offer for visually challenged and blind people an accessible computer. A french guy is beyond it and there is a kickstarter-like compain to support it (french page about it http://linuxfr.org/news/financement-participatif-de-handydv-..., couldn't find anything in english).