Loss of vision; No light perception (NLP); Low vision; Vision loss and blindness
Blindness is a lack of vision. It may also refer to a loss of vision that cannot be corrected with glasses or contact lenses.
People with vision worse than 20/200 are considered legally blind in most states in the United States.
Vision loss refers to the partial or complete loss of vision. This vision loss may happen suddenly or over a period of time.
Some types of vision loss never lead to complete blindness.
Blindness has many causes. In the United States, the leading causes are:
The type of partial vision loss may differ, depending on the cause:
Other causes include:
Kraut JA. Vision rehabilitation. In: Tasman W, Jaeger Ea, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 46.
Olitsky SE, Hug D, Smith LP. Disorders of Vision. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 620.
Sterns GK, McCormick GJ. Ophthalmologic disorders. In: Duthie EH, Katz PR, Malone ML, eds. Practice of Geriatrics. 4th ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 24.
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