Eye Matters
July 19, 2011

Legal Blindness

20/20 is regarded to be the international standard for normal vision. This means that a person sees the smallest symbols or letters on an eye chart when sitting or standing 20 feet away from the chart.{{more}}

There are some people who cannot see normally, even with a spectacle correction or contact lenses. Usually this is due to a medical condition and these people are classified as visually handicapped or impaired.

A person is deemed to be legally blind if vision drops to one tenth of normal or about 20/200 in the better eye with corrective lenses. This does not mean that they cannot see at all. 20/200 means that a person standing at 20 feet from an eye chart can see what a person with normal vision can see at 200 feet. A legally blind person usually cannot see the line below the second big E at the top of an eye chart. Also, if the field of vision is less than 20 degrees (tunnel vision), a person can qualify as legally blind. Legal blindness is the criteria used to determine eligibility for disability benefits. Some countries have slightly different criteria, but the rule is generally the same.

That is why some people walking around with 20/20 vision and less than 20 degrees of visual field could be considered legally blind. It also follows that there are also people who see well with only one eye, who are not legally blind. All those whose glasses allow them better vision than 20/200 do not qualify for legal blindness.

If the handicap started since childhood, most legally blind patients function very well. Telescopes and magnifying lenses help adults and older children see better in the distance. Learning Braille and walking with a cane or a seeing eye dog may be indicated, especially when vision is extremely poor.

Children should be evaluated for developmental challenges by experienced teachers and professionals. Parents and teachers should be on the lookout for such situations, through mandatory vision screening.

Some may benefit from occupational training, mobility and orientation training and social service. There are many new devices on the market to help the visually handicapped, such as watches that can be read with the fingers, talking watches, calculators and computers. Also books, audios and scanners that have the ability to turn print into Braille.

A great place to start your inquiries is at the National Society of and for the Blind (NSOFB), located at the Lions building at Frenches gate.

Dr Kenneth Onu is a resident Consultant Ophthalmologist at the Beachmont Eye Institute/Eyes R Us Send questions to: Beachmont@gmail.com

Tel: 784 456-1210