There are NO cases of schizophrenia in people who were blind since early childhood. Possibly changes in the brain confer a protective effect against schizophrenia, although NOT against other brain disorders.

Very interesting!  This is going to be very helpful with the direction research takes ;)

So it's reasonable to say there's a correlation between schizophrenia and eyesight?

Not that that necessarily helps with developing remedies. 

Maybe for blind people the area of their brain that manages visualization is less developed, and the most powerful aspe vs of scitzophrenic hallucination are visual in nature. Many are also audible and physical but if the trigger is visual then the mania cannot develop.

Entirely possible, Ayori.