Just wondering

According to USA Today, Iowa is granting permits to acquire or carry guns in public to people who are legally or completely blind. According to the article, denying them a permit would violate the ADA. Now I know that some people who are legally blind might be able to see well enough to aim and shoot at something. But someone who is blind? That thought makes me uncomfortable. Where is the line between political correctness and common sense? We are required (at least in theory) to pass a vision test to get a driver's license. Is it too much to ask for someone to pass a vision test to own a firearm? At what point do the rights (and perhaps safety) of the many outweigh the rights of the not quite so many? When did we as a society decide that everyone is entitled to everything, and that saying no, you're not qualified is discrimination?