Blindness refers to a condition where a person suffers from any of the following
a. Total absence of sight.
b. Visual acuity not exceeding 6/60* or 20/200 (Snellen) in the better eye with best correcting lenses
c. Limitation of field of vision subtending an angle of 20 degree or worse
* 6/60- means one can see at 6 metres what someone with standard vision could see from 60 metres away.
In India a person with a VA < 6/60 is legally blind
Person with low vision means a person with impairment of vision of less than 6/18 to 6/60
with best correction in the better eye or impairment of field in any one of the following categories:
a. Reduction of fields less than 50 degrees
b. Heminaopia with macular involvement
c. Altitudinal defect involving lower fields
20/20 is considered normal vision.
Categories of Visual Disability