The classification rules of the International Federation for Football 5-a-side state that athletes with a visual impairment are eligible to compete in the sport at the Paralympics.
All four outfield players must wear blackout eyeshades to ensure fairness. The goalkeeper may be fully sighted but he is not allowed to leave his penalty area.
The football contains ball bearings to produce a noise when it moves.
Read an overview of classification at the London 2012 Paralympic Games