The key detail here is "legally blind". "Legally blind" doesn't mean sightless. It means poor eyesight even after correction. According to http://vision.about.com/od/severevisionloss/f/legalblind.htm "legal blindness occurs when a person is unable to achieve at least 20/200 vision in the best eye even when eyeglasses or contact lenses are worn."

Without my eyeglasses my eyesight is probably worse than 20/200. So if my eyeglasses were knocked off, such as might happen in the beginning stage of an assault, my eyesight would be reduced to the level of 'legally blind'. However, that doesn't mean I wouldn't be able to see well enough to defend myself with a concealable handgun. I wouldn't need 20/20 vision to recognize (and stop) a nearby attacker.

In my opinion, the answer to your questions is, it depends. Legally blind is a label, not a capability. If the person is capable they should be permitted to do anything they want so long as it does not unduly put other peoples' lives in danger. I don't believe that someone with poor vision carrying a concealable weapon would put my life in danger as long as they use good judgment, and judgment is independent of visual acuity.

Dennis