> I'm pretty sure that's why, 100 years ago, there were so many blues folks with names like "Blind Lemon Jefferson"

Also because in a predominantly agricultural society, music was one of very few self-sustaining pursuits for a blind (or otherwise unsuited to farm work) person. Looking through the 'blind' names in [0] most were either born blind or had an alternate explanation (usually accidents) for their blindness.

[0] https://en.wikipedia.org/wiki/List_of_nicknames_of_blues_mus...