A good friend of mine is a blind rehabilitation specialist. We've spent a lot of time discussing tech for the blind. We always run up against the same issues:

A good friend of mine is a blind rehabilitation specialist. We've spent a lot of time discussing tech for the blind. We always run up against the same issues: The market is limited in total numbers, the blind tend to be under-employed or un-employed and therefore have limited $$ for technology widgets, and the market is fragmented. Those who go blind later in life, like my friend and the Veteran's Hospital clients he works with, tend never to learn braille because there is just too much else of a higher priority in their rehab program and the ROI just isn't there. My aging uncle falls into that category, plus his severe gout in his fingers has pretty much destroyed his sense of touch. A braille output surface is going to be expensive to build just about any way I can imaging tackling it (please, be more insightful than me and invent a cheap one), and there just aren't going to be a lot of takers.