Get the facts about nutrition and dietary information. Learn about healthy food, vitamins and dietary supplements.

Symptoms, diagnosis and prevention, rehabilitaion & information of specific conditions.

Not Feeling well?


secure email

Keep Your Personal Information Safe

Health Encylopedia

Definition The loss of normal or correctable vision.
Alternative Names Loss of vision
Considerations Blindness can be partial, with loss of only part of the vision. It can also be complete, in which case there is no perception of light. People with vision worse than 20/200 vision are considered legally blind. Blindness has many causes, yet the incidence of true blindness in the United States remains low. Accidents, diabetes , glaucoma, and macular degeneration account for most blindness in the United States. Worldwide, Vitamin A deficiency is the leading cause of blindness.
Common Causes In the United States:
  • accidental trauma to the eyes (such as
  • chemical burns , or injuries from bungie cords, fishing hooks, racket ball, fireworks, and similar objects)
  • diabetes
  • glaucoma
  • macular degeneration
  • vascular occlusions
  • amblyopia
  • Less common causes
  • optic neuritis
  • after eye surgery
  • stroke
  • Vitamin A deficiency
  • Tay-Sachs disease
  • retinitis pigmentosa
  • retinoblastoma
  • lead poisoning
  • optic glioma
  • trachoma
  • (Chlamydial
  • conjunctivitis ) Other (more rare) causes:
  • Jansky-Bielschowsky syndrome
  • Krabbe disease
  • retrolental fibroplasia
  • achromatopsia
  • Albers-Schonberg (osteopetrosis)
  • Alpers diffuse cerebral degeneration
  • anophthalmos
  • Batten-Mayou
  • Cockayne syndrome
  • cryptophthalmia
  • gonococcal ophthalmia
  • Kufs' disease
  • Leber congenital amaurosis
  • Niemann-Pick disease
  • Norrie's disease
  • onchocerciasis (river blindness)
  • Refsum syndrome
  • Scholz disease
  • Trisomy-13
  • Vogt-Spielmeyer
  • Home Care Safety and the ability to dress, eat, and function independently are of prime importance to a person with blindness. Many services are available to provide in home training and support services for people to function independently.
    Call your health care provider if Contact health care provider or emergency room immediately:
  • partial or complete blindness develops in one or both eyes.
  • sudden visual loss occurs.
  • What to expect at your health care provider's office The medical history will be obtained and a physical examination performed. Medical history questions documenting blindness in detail may include:
  • time pattern
  • When did this begin?
  • Did it occur suddenly or gradually?
  • Does it occur only occasionally? How often?
  • How long does it last?
  • When does it occur, in the evening, morning, or all the time?
  • quality
  • Is the blindness complete?
  • Is there any residual vision -- for example, can light and dark be distinguished?
  • Are both eyes affected?
  • other symptoms
  • What other symptoms are also present?
  • Is there
  • eye pain ?
  • Is there a
  • headache ?
  • additional information
  • What medications are being taken?
  • Is there a family history of eye problems or blindness?
  • Have you had an injury to the eye or head?
  • A routine eye examination will be performed. The health care provider will check visual acuity , eye movements, pupils, back of the eye ( ophthalmoscopy ), and eye pressure ( tonometry ) when indicated. An overall medical evaluation will be done if indicated. Loss of vision should never be ignored, thinking it will get better. Contact your doctor or emergency room immediately.