A player's visual acuity must not be better than
20/200 with the best practical eye correction or else the player's
field of vision must not be better than 20 degrees. The three
classifications of blindness are B1 (totally blind to light
perception), B2 (able to see hand movement up to 20/600 corrected), and
B3 (from 20/600 to 20/200 corrected).