What does legally blind mean? It means the people who have the best corrected vision of 20/200. If the people took off their glasses or contact lenses, then they can barely see the foot right in front of their face. What does 20/200 vision mean? It means the legally blind people can only see the same details of a subject 20 feet away while normal people can see the same thing 200 feet away. Without eyeglasses, they literally blind that they can't see the people just next to them. Eyeglasses of course could help them, although not very much, but at least they can see things. The so called blindness will not affect their lives. We should put it this way that eyeglasses is necessary for these people. Yet the eyeglasses may not be the ordinary ones, they are especially prescribed by ophthalmologist. There are five types of main optical devices for legally blind people, including magnifying spectacles, magnifiers, stand magnifiers, telescopes and closed-circuit television.