What happens when a baby is born extremely near-sighted? Are they ever mistaken for being blind?

Yes . Yes, a baby can be born extremely near sighted. I saw a girl myself who was thought to be blind and it turns out she was severely nearsighted. A proper eye exam with something called a "cycloplegic refraction" can detect it. But only once you give the glasses will you be able to tell if the child can see. Keep in mind that although possible, babies are almost exclusively far sighted at birth .