Signs and Symptoms
Blindness is defined by the World Health Organization as vision in a person's best eye of less than 20/500 or a visual field of less than 10 degrees. This definition was set in 1972 and there is ongoing discussion on if it should be altered somewhat.
Read more about this topic: Blind People
Famous quotes containing the words signs and/or symptoms:
“Wherever I look, I see signs of the commandment to honor one’s parents and nowhere of a commandment that calls for the respect of a child.”
—Alice Miller (20th century)
“Social movements are at once the symptoms and the instruments of progress. Ignore them and statesmanship is irrelevant; fail to use them and it is weak.”
—Walter Lippmann (1889–1974)