It’s a great question, and congrats on your comment becoming TikTok famous. ☺️
There’s some nuance to it, too. Only congenital blindness seems to be strongly protective against schizophrenia, while people who developed blindness later in life or still have some degree of vision, don’t seem to have the same protection. It also seems to be specific to schizophrenia. So, I think it’s fair to say that having vision and growing up with it may somehow play a role in the development of the illness.
As someone who relies heavily on empirical input, this illness has always scared me the most. Imagine not being able to trust what you hear or see on a daily basis. I hope research will eventually uncover the causes of schizophrenia and lead to better ways of helping those who suffer from it. 🙏