By successful, I mean made it out to the large world market or being massively funded. After looking online it seems that the most relevant research is the one done by Bach-y-Rita about the [seeing with tongue](http://www.youtube.com/watch?v=OKd56D2mvN0) in the 70's. Since then there were no significant breakthroughs. Is there a reason for that? Did someone prove that brain plasticity is limited?