The overall field of visual paraperception is very interesting. You have Charles Bonnet Syndrome as described, and other really interesting phenomena like blindsight and complex visual agnosias, and then Anton-Babinski anosognosia where a patient IS blind but confabulates their visual field and maintains they can see!
I started reading into this from my interest in neuropsychiatry, but what is most interesting is that visual hallucinations are really quite rare in the schizophrenic population. Most visual hallucinations, it seems, have nothing to do with mental illness.
also, if you are blind from birth or go blind within a year of birth you won't develop schizophrenia. those folk are completely absent in the population.
Great point. I forgot about that one. It’s a very interesting observation and I’ve never been able to square it with my other reading into SCZ