T13 (classification)

B3 is a medical based Paralympic classification for blind sport. Competitors in this classification have partial sight, with visual acuity from 2/60 to 6/60. It is used by a number of blind sports including para-alpine skiing, para-Nordic skiing, blind cricket, blind golf, five-a-side football, goalball and judo. Some other sports, including adaptive rowing, athletics and swimming, have equivalents to this class.

The B3 classification was first created by the IBSA in the 1970s, and has largely remained unchanged since despite an effort by the International Paralympic Committee (IPC) to move towards a more functional and evidence-based classification system. Classification is often handled on the international level by the International Blind Sports Association (IBSA) although it is also handled by national sport federations. There are exceptions for sports like athletics and cycling.

Equipment utilized by competitors in this class may differ from sport to sport, and may include sighted guides, guide rails, beeping balls and clapsticks. There may be some modifications related to equipment and rules to specifically address needs of competitors in this class to allow them to compete in specific sports. Some sports specifically do not allow a guide, whereas cycling and skiing require one.

B3 is a disability sport classification for people who have partial vision. The International Blind Sports Federation (IBSA) defines this classification as "From visual acuity above 2/60 to visual acuity of 6/60 and/or visual field of more than 5 degrees and less than 20 degrees." The Canadian Paralympic Committee defined B3 as "No more than 10% functional vision." Competitors in this class "can make out shapes with the help of glasses".

...
Wikipedia