BlindnessBlindness can be defined physiologically as the condition of lacking visual perception.
The definition as it applies to people thus legally classified is more complex.
In North America and most of Europe, legal blindness is defined as visual acuity (vision) of 20/200 (6/60) or less in the better eye with best correction possible. This means that a legally blind individual would have to stand 20 feet from an object to see it with the same degree of clarity as a normally sighted person could from 200 feet.
In many areas, people with average acuity who nonetheless have a visual field of less than 20 degrees (the norm being 180 degrees) are also classified as being legally blind. Approximately ten percent of those deemed legally blind, by any measure, are fully sightless. The rest have some vision, from light perception alone to relatively good acuity.
Visually impaired and blind people have devised a number of techniques that allow them to complete daily activities using their remaining senses.
|"The only thing worse than being blind is having sight but no vision"|