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, signs and/or symptoms:
“Time has an undertaking establishment on every block and drives his coffin nails faster than the steam riveters rivet or the stenographers type or the tickers tick out fours and eights and dollar signs and ciphers.”
—John Dos Passos (1896–1970)
“[Christianity] endeavors equally to establish these two things: that God has set up in the Church visible signs to make himself known to those who should seek him sincerely, and that he has nevertheless so disguised them that he will only be perceived by those who seek him with all their heart.”
—Blaise Pascal (1623–1662)
“Protest, evasion, merry distrust, and a delight in mockery are symptoms of health: everything unconditional belongs in pathology.”
—Friedrich Nietzsche (1844–1900)