What is the definition or description of: legal blindness?

See below.: This is a legal, not medical, term. A typical definition is visual acuity that is 20/200 or less in the best eye that has the best possible glasses or contact lens prescription in place, and/or constriction of the visual field to less than 10 degrees from centration in both eyes. Note that the defintion requires that glasses or contact lenses be used when the vision is tested.

Varies by State: Legal blindness is best corrected vision below a certain standard, usually 20/200 in most states. It can also include a restriction of the peripheral field which can be quite handicapping in disease such as retinitis pigmentosa.

Even with glasses: Legal blindness (20/200 in the us, 6/60 per the who) is defined as a) 20/200 or less visual acuity in the better-seeing eye with best correction, b) a visual field of 10 degrees diameter or less in its greatest meridian, or c) a combination of visual acuity and visual field loss equivalent to a or b. Anyone who says "you are legally blind without your glasses" is coercing you to have lasik surgery.