Legal Blindness

Normal vision, or 20/20 vision, means that a person can read the smallest letters or see the pictures on an eye chart when standing 20 feet away from the chart. Some people cannot see normally even with eyeglasses or contacts because a medical condition affects their vision. These people are called visually impaired or visually disabled.

If a visual impairment limits vision to 20/200, or one-tenth of normal vision, a person is considered legally blind. Being legally blind, however, does not mean a person is totally unable to see. People with 20/20 vision but less than 20 degrees of side (peripheral) vision can also qualify as legally blind. People who see well with only one eye are not considered legally blind, nor are people who wear glasses to see better than 20/200.

Most legally blind people function quite well, especially if they have been visually impaired since childhood. Older children and adults with visual impairments may need magnifying lenses for reading and telescopes for distance viewing. People with very poor vision may need to learn Braille and walk with a seeing-eye dog or a cane.
Young children with visual disabilities should have help from a teacher of the visually impaired and should be evaluated for developmental problems by professionals experienced with visual impairments. Parents may need to be advocates for their children to obtain needed services through the school system.

Visually impaired people of all ages benefit from social service, occupational therapy, and orientation and mobility training. Many new devices are available to help them cope with vision loss, including books on audiotape, scanners that can turn print into Braille, watches that can be read with the fingers, and talking computers and calculators.

Living With Vision Loss in One Eye

People who lose vision in one eye because of an injury or a medical condition must adapt to a narrower field of vision and loss of depth perception. They may still see small objects as well as before, assuming the other eye is normal.

At first, adults who lose vision in one eye may have a few fender-benders, and they may have difficulty reaching out accurately to shake hands. This is due to the lack of depth perception as well as a narrower field of vision. The patient will soon learn to turn his or her head more when driving, reading, or doing other activities in order to compensate for the lack of depth perception and smaller field of view. With patience and time, they learn to use other clues to help them navigate the world around them and to function normally.

Assuming that the unaffected eye is normal, a person with vision loss in one eye is not considered legally blind. In addition, the patient is also eligible for a driver's license and is able to work in almost any occupation. There may be some jobs that a person with vision loss in one eye cannot safely perform, but they are few. Dr. Haas and your job safety coordinator can provide advice and guidance.

Living With Low Vision

Low vision is loss of eyesight that makes everyday tasks like reading, writing, crossing the street, or watching television difficult. When vision cannot be improved with eyeglasses, medicine, or surgery, people with low vision need to know how to best maintain their existing vision and best utilize the vision they still have.

Low vision can affect central or peripheral vision, depth of perception, or visual processing.

Low vision may be caused by eye injuries or conditions such as age-related macular degeneration, glaucoma, diabetic retinopathy, or retinitis pigmentosa.
Vision rehabilitation can help people with low vision. You can learn new strategies to complete daily activities, regaining confidence in your ability to live independently despite vision loss.

There are many low vision aids available, such as magnifying spectacles, hand and video magnifiers, and telescopes that can help you make the most of your remaining vision. Learning to adjust lighting appropriately can often improve your vision for reading, cooking, dressing, and walking up and down stairs.

What can you do to prevent vision loss?

Early examinations can help reduce the risk of vision loss. If you are experiencing difficulty seeing, it is very important to visit Dr. Haas to get a comprehensive examination. Diagnosis and possible treatment of your eye condition may slow progression of the vision loss and in some cases can improve vision.
A low vision examination may also be helpful. Rehabilitation may be possible. A low vision examination differs from a normal eye exam in that it is typically longer and involves a number of tests that you may not be familiar with.

Typically, the low vision doctor reviews your medical and ocular history and then asks you for detailed information about your vision problems and how they are affecting your everyday life.

After taking your history, your low vision doctor will do a number of tests to assess your vision. These tests may include:

  • refraction to assess your vision and determine if glasses may be of any use;
  • dilated internal examination of the eye;
  • visual field testing of your peripheral vision;
  • ocular function testing for depth perception, color perception, and contrast sensitivity;
  • ocular motility testing to determine how well your eyes move; and
  • evaluation and trial of many different low vision devices, such as magnifiers, improved lighting, closed-circuit TVs, and electronic devices.

Having frequent eye examinations helps to assure that your eyes will remain as healthy as possible. If you are experiencing difficulty with your vision, it is important to see your ophthalmologist right away. A comprehensive eye examination can catch eye-related problems early and help reduce vision loss.



Remember, you are not alone, and you deserve access to the information and tools you need to make the most of your sight. For more information about low vision, vision rehabilitation, and low vision aids, use these resources:

American Academy of Ophthalmology Web site

American Foundation for the Blind
11 Penn Plaza, Suite 300
New York, NY 10001

Lighthouse International
111 East 59 th Street
New York, NY 10022

National Association for Visually Handicapped
22 West 21 st Street, 6 th Floor
New York, NY 10010

National Library Service for the Blind and Physically Handicapped
Library of Congress
1291 Taylor Street, NW
Washington, DC 20011

Vision Connection