Blindness is a lack of vision. It may also refer to a loss of vision that cannot be corrected with glasses or contact lenses.
Partial blindness means you have very limited vision.
Complete blindness means you cannot see anything and do not see light. (Most people who use the term “blindness” mean complete blindness.)
People with vision that is worse than 20/200 with glasses or contact lenses 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.
Loss of vision; No light perception (NLP); Low vision; Vision loss and blindness
Blindness has many causes. In the United States, the leading causes are:
Accidents or injuries to the surface of the eye (such as
chemical burnsor sports injuries)
The type of partial vision loss may differ, depending on the cause:
cataracts, vision may be cloudy or fuzzy, and bright light may cause glare
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 missing areas of vision
With macular degeneration, the side vision is normal but the central vision is slowly lost
Other causes of vision loss include:
- Blocked blood vessels
- Complications of premature birth (
- Complications of eye surgery
Lazy eye Optic neuritis Stroke Retinitis pigmentosa
- Tumors such as
retinoblastomaand optic glioma
When you have low vision, you may have trouble driving, reading, or doing small tasks such as sewing or making crafts. You can make
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.