B1: Competitors in this classification are totally or almost totally blind. No functional vision, no light perception in either eye up to some light perception, but inability to recognize the shape of a hand at any distance or in any direction.
B2: Competitors in this classification have partial vision up to 3% to 5% functional vision. They have the ability to recognize objects up to a distance of 2 metres and may see the shape of a hand but have a field of vision less than 5 degrees.
B3: Competitors in this classification have no more than 10% functional vision. They can make out shapes without the help of glasses. They can recognize objects between 2 and 6 metres away and/or visual field of more than five degrees and less than twenty degrees.