That would be a reasonable explanation I think if the rates of schizophrenia were merely lower amongst the blind. But what's said here is something quite ab it

That would be a reasonable explanation I think if the rates of schizophrenia were merely lower amongst the blind. But what's said here is something quite ab it stronger than that: there are zero known cases of schizophrenia among the congenitally blind. If true, and if not simply a sampling artifact, it implies something pretty profound about the nature of schizophrenia as a disorder that has hitherto not been known.