Blind Lemon Jefferson. Blind Willie McTell. Blind Blake. Blind Boy Fuller (on this record). Blind Willie Johnson. Why are there so many blind blues musicians in the Thirties? Was this some kind of clever marketing ploy by the emerging record industry? Were these people really blind?
First of all: blindness can be a condition caused by poverty or malnutrition. Conditions in the Thirties in the Deep South (of the United States) were harsh and may have led to a statistically higher percentage of blind people. More than that, possible bootlegging and bad drinking might have led to ethanol poisoning, which also can be a cause for blindness.
Second: in a rural society, blindness is crippling. If you cannot safely wield any farming equipment, or pick cotton, what else can you do when you cannot see? Music is the bread and butter of these communities, or so my romantic vision tells me. After a hard days work you come home to your wife and kids, and to listen to the blind man of the village singing his heart out about your bad situation. In that way, even blind people can attribute to the group as a whole.
And yes, there were indeed musicians that just called themselves blind to sound interesting (I’m looking at you, Blind Joe Death).