People with total blindness or no light perception see nothing at all, according to Nicholas Gerbis for Live Science. Some individuals with NLP retain the ability to distinguish between light and dark using different cells in the eyes. The brain processes these signals in a different region than normal vision.
Blindness covers a wide range of vision loss, notes the American Foundation for the Blind. Visual impairment describes individuals who cannot read the newspaper with the best correction. In the United States, a person is legally blind if his corrected vision is 20/200 or less. Only 18 percent of individuals with visual impairment are totally blind or NLP.