Thursday, October 18, 2012

What do the vision numbers mean?

I am trying to see what the definitions of blindness are, and if my brother is considered legally blind.
He has 25/50 in one eye, and the other eye is totally blind. He has failed the field exam for the drivers license, and does not have peripheral vision at all. I know the legal definition of blindness is 20/200 in the better eye, with corrective lenses. I am unsure how the 25/50 relates to the 20/200.
>>> What do the vision numbers mean?