Honestly, I kind of relate because I don’t have that many serious hobbies or defining things I like. I thing the best thing to do would just be dabbling in different stuff and just trying as many things as he can! Like legos, language learning, traveling (even if your own city), reading, playing an instrument, sculpture, abstract painting, coding, or bunch of other stuff. Just try it until he figures out something that might stick for him.

Reading, creative writing, Music (both as a listener and a music maker), ham radio, bingo ... ?

Is he interested in music at all?

Can you tell us what he likes? What are his passions? Does he enjoy reading? Writing? Anime? Movies? There are probably a lot of things we can suggest if we know a little more about his likes and dislikes.

Also, as far as relationships, I know it's hard in high school to take and it must be harder when you're blind or have another hurdle to jump over, but a relationship isn't the end all be all. Your friend is very young, and there will be someone for him. I'm 30, I didn't date until I was 18 and my little brother -- he's blind, I'm not -- hasn't ever really dated anyone since he went blind 2 years ago.

Your friend could try reading groups, writing clubs, anime clubs, debate teams, and other things like that. It all depends on what your school offers, his passions, and his time!