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Braille
: Glossary » Blindness |
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Blindness
Partial or complete loss of sight with visual acuity of not greater than 20/200 in the better eye with correction or a field not subtending an angle greater than 20 degrees. Blindness may be caused by injury, by lesions of the brain or optic nerve, by disease of the cornea or retina, by pathological changes originating in systemic disorders and by cataract, glaucoma, or retinal detachment. Blindness can be caused by infectious diseases and by dietary deficiencies in underdeveloped countries where medical care is inadequate. Specific kinds of blindness include night blindness that may progress to total blindness, color blindness (an inability to distinguish colors) and snow blindness (a temporary condition caused by the reflection of sunlight on snow).
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