Yesterday we went down to Jaffa and saw a show at the Na LaGa'at center. It was presented by a troupe of actors, some quite talented, who are deaf and blind.
Both. They don't see (some used to, a few have remnants of sight), and also don't hear (some used to, and some still have remnants). Can you even begin to imagine the extent of their solitude, of their disconnect from the rest of us? On stage, they have no way of knowing what's happening right next to them, unless through physical contact. As one of them says during the show, I need people to shake my hand otherwise I don't know they exist.
Na LaGa'at (which means "please touch") has built a social center for people who are either blind, or deaf, or both. Here's their website - go have a look. They claim they're the only such group in the world, and I expect they're right. If you ever have the chance to visit them, in the port of Jaffa, one of the world's oldest ports - don't miss it. If the troupe ever comes to a city near you - say, 500 miles - go see them. They can't see you, but they'll make your effort worthwhile and unforgetable.