Blindness And Vision Loss
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Definition
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.
Alternative Names
Loss of vision; No light perception (NLP); Low vision; Vision loss and blindness
Common Causes
Blindness has many causes. In the United States, the leading causes are:
The type of partial vision loss may differ, depending on the cause:
With cataracts, vision may be cloudy or fuzzy, and there may be problems seeing shapes
With diabetes, vision may be blurred, there may be shadows or missing areas of vision, and difficulty seeing at night
With glaucoma, there may be tunnel vision and blurry vision
With macular degeneration, the side vision is normal but the central vision is slowly lost
Other causes include:
- Blocked blood vessels
- Complications of premature birth (retrolental fibroplasia)
- Complications of eye surgery
- Lazy eye
- Optic neuritis
- Stroke
- Retinitis pigmentosa
- Tumors such as retinoblastoma and optic glioma
References
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.
Review Date: 7/28/2010
Reviewed By: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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 2004 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
Alternative Names
Loss of vision; No light perception (NLP); Low vision; Vision loss and blindness
Home Care
The kind of home assistance you need will depend on your type of vision loss. 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 blind people need to function independently.
Ideas to keep things organized at home:
Always keep certain items in the same drawer, cabinet, table, or counter space.
Learn to recognize the shape of certain items, such as egg containers or cereal boxes.
Use plastic rings to hold pairs of socks together, whether you are washing, drying, or storing them.
Use small Braille labels, including a simple form of Braille called uncontracted Braille.
Use small raised dots, rubber bands, Velcro, or colored tape to label items that are hard to read.
Use caulking, raised rubber, or plastic dots to mark the "on," "bake," and certain temperature settings on the furnace thermostat and dials on stoves, toasters, the washer, and dryer.
Use a phone with large numbers and memorize the keypad.
Fold different types of paper money in a different way. For example, you can fold a $10 bill in half or double fold a $20 bill.
Use Braille or large-print checks.
Tips to help you get around and stay safe at home:
If possible, learn to use a long white cane to help you get around on your own.
When walking with someone else's help, grasp their arm just above the elbow. Walk slightly behind them to follow their motions.
Remove lose wires or cords from the floor.
Remove loose throw rugs.
Do not keep small pets in your home.
Fix any uneven flooring in doorways.
Have good lighting.
Put hand rails in the bathtub or shower and next to the toilet.
Place a slip-proof mat in the bathtub or shower.
A number of different low-vision aids can help:
Magnifiers
Technology aids to make it easier to use cell phones and computers
Watches made for people with low vision, or talking watches and clocks
Call your health care provider if
Sudden vision loss is always an emergency, even if you have not completely lost all vision. You should never ignore loss of vision, 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 give you a short amount of time to be successfully treated.
What to expect at your health care provider's office
A complete and thorough eye examination will be performed. The treatment will depend on the cause of the vision loss.
For long-term vision loss, see a low-vision specialist, who can help you learn to care for yourself and live a full life.
References
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.
Review Date: 7/28/2010
Reviewed By: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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 2004 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
Review Date: 7/28/2010
Reviewed By: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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 2004 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.