Blindness, in this sense, is used both metaphorically (to refer to someone who was ignorant but later became knowledgeable) and literally, as a reference to those healed in the Bible. In the later years of his life, Newton himself would go blind. H. G. Wells story "The Country of the Blind" explores what would happen if a sighted man found himself trapped in a country of blind people to emphasise societys attitude to blind people by turning the situation on its head. Bob Dylans anti-war song "Blowin in the Wind" twice alludes to metaphorical blindness: How many times can a man turn his head // and pretend that he just doesnt see... How many times must a man look up // Before he can see the sky? Contemporary fiction contains numerous well-known blind characters. Some of these characters can see by means of devices, such as the Marvel Comics superhero Daredevil, who can see via his super-human hearing acuity, or Star Treks Geordi La Forge, who can see with the aid of a VISOR, a fictional device that transmits optical signals to his brain. Sports
Blind and partially sighted people participate in sports, such as swimming, snow skiing and athletics. Some sports have been invented or adapted for the blind, such as goalball, association football, cricket, golf, tennis, bowling, and beep baseball. The worldwide authority on sports for the blind is the International Blind Sports Federation. People with vision impairments have participated in the Paralympic Games since the 1976 Toronto summer Paralympics.
An individual shall also be considered to be blind for purposes of this title if he is blind as defined under a State plan approved under title X or XVI as in effect for October 1972 and received aid under such plan (on the basis of blindness) for December 1973, so long as he is continuously blind as so defined. Temporary vision impairment
Vision impairment for a few seconds, or minutes, may occur due to any of a variety of causes, some serious and requiring medical attention. Health effects
General functioning
Visual impairments may take many forms and be of varying degrees. Visual acuity alone is not always a good predictor of an individuals function. Someone with relatively good acuity (e.g., 20/40) can have difficulty with daily functioning, while someone with worse acuity (e.g., 20/200) may function reasonably well if they have low visual demands. It is also important to note that best-corrected visual acuity differs from presenting visual acuity; a person with a "normal" best corrected acuity can have "poor" presenting acuity (e.g. individual who has uncorrected refractive error).