What & # 039; Blind & # 039; Really it mean?

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Updated December 16, 2014.

Written or reviewed by a board-certified physician. See About.com Examination Council.

Question: What does it mean blind!

Answer: A person is considered blind if he or she has a best corrected vision 20/200 in the better eye sight.

Many people think that they are, because if a pair of glasses or contact lenses that they can not see a foot in front of his face are blind away. However, if put in your vision correction, you have enough 20/20. Provided that it can be corrected to 20/20 with some visual aid, is not as blind.

Did you know that the "legal blindness" is at the best level of vision you can achieve the best view, or on the basis can be cured? Most governments and health care institutions agree that the legal blindness is defined as one of the following:

1. Legal blindness as visual acuity of 20/200 or worse in the better eye sight defined.
2. A field that is only 20 degrees.

What "blind" really mean?

Is your blind eyes see better can not be corrected better than 20/200 with glasses or contact lenses. The best way to understand this is to a normal person to think with 20/20 vision. This person has the ability to remain 200 meters away from an object and see every detail, while legally blind person would have to move all the way up to 20 meters, to see the same level of detail. A legally blind person has difficulty seeing far away or very near objects.

If a person is a field of 20 ° only, tunnel vision considered, he or she will be blind.

A normal person has a visual field of 180 degrees. People with a limited field of view can be seen central detail, but can not see anyone standing beside his own shoulder. These people have difficulty with mobility, such as safe driving is almost impossible. Hiking in a dark movie theater can be a big problem.

The definition of legal blindness was developed to help people on welfare. Also, as you can imagine, the Department of Motor Vehicles (DMV) has to have a safer means for measuring the vision of maintaining our roads and highways.

_Source:

_{Lavine, Jay B. Eye Care book, p.24-25. New Books 2,001th}