The classifications 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 Federation (IBSA) but it sometimes handled by national sport federations.
B2- B2 is a disability sport classification for people who are visually impaired.The International Blind Sports Federation (IBSA) defines this classification as "visual acuity ranging from LogMar 1.50 to 2.60 (inclusive) and/or visual field constricted to a diameter of less than 10 degrees." It thus falls between the B1 and B3 classifications.
B3- B3 is a disability sport classification for people who have partial vision.The Interantional Sports Federtaion(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.