For more information about participating in competitive sports with a visual impairment or coaching blind Judo athletes see Judo for Blind Athletes.

US Paralympian Richard Keeney in action

Before and after practicing Judo or engaging in a match, opponents bow to each other. Bowing is an expression of gratitude and respect. In effect, you are thanking your opponent for giving you the opportunity to improve your technique.
…..Dr. Jigoro Kano