No, going to jail doesn’t ruin your vision, unless you get punched in the eye or something. This ex-con had eyesight problems all of his life and didn’t have the money for glasses. One day, while staying at a halfway house (a house that helps soon-to-be-released convicts get accustomed to society), the house paid for his eyeglasses.
That day, he could see everything clearly. Before, his eyesight was a blurry mess, and he had to live in jail for ten years with terrible vision. We’re glad that this guy, who’s been out of jail for 20-plus years now, is doing much better.