MedlinePlus Medical Encyclopedia: Blindness

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Blindness

Contents of this page:
Illustrations Alternative names Definition Common Causes	Home Care Call your health care provider if What to expect at your health care provider's office

Illustrations

Neurofibromatosis I, enlarged optic foramen

Alternative names Return to top

Loss of vision

Definition Return to top

Blindness is the loss of vision, not correctable with lenses. 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 or a field of vision of less than 20 degrees in the better eye are considered legally blind.

Common Causes Return to top

Blindness has many causes. In the United States, the leading causes are diabetes, glaucoma, macular degeneration, and accidents (such as chemical burns or injuries from bungie cords, fishing hooks, fireworks, racket balls, and similar objects).

Worldwide, the leading causes of blindness are cataracts, onchocerciasis ("river blindness"), trachoma, leprosy, and vitamin A deficiency.

Other causes include:

blocked blood vessels
complications of premature birth (retrolental fibroplasia)
complications of eye surgery
lazy eye
optic neuritis
stroke
Tay-Sachs disease
retinitis pigmentosa
retinoblastoma
lead poisoning
optic glioma

Home Care Return to top

It is important for a blind person to be able to dress, eat, function independently, and stay safe. Many services are available that provide the training and support that allow blind people to function independently.

Call your health care provider if Return to top

Sudden vision loss is always an emergency, even you have not completely lost all vision. Loss of vision should never be ignored, thinking it will get better.

Contact an ophthalmologist or go to the emergency room immediately. Most serious forms of vision loss are painless, and the absence of pain in no way diminishes the urgent need to get medical care. Many forms of vision loss only have a short amount of time where they can be successfully treated.

What to expect at your health care provider's office Return to top

A complete and thorough eye examination will be performed. The treatment plan will depend on the cause.

Update Date: 9/10/2003

Updated by: Edward B. Feinberg, M.D., M.P.H., Professor and Chair, Ophthalmology, Boston University School of Medicine, Boston, MA. Review provided by VeriMed Healthcare Network.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2002 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.