Goalball first appeared at the Paralympic Games, Toronto 1976 for men only and then in New York 1984 for women as well. Goalball was created as a form of rehabilitation for injured servicemen returning from World War II. The game is played by athletes with visual impairment, players wear eyeshades to ensure that a level paying field regardless of their residual vision. It is played by two teams of three using a ball with bells inside; the ball is the size of a basketball but twice the weight. The object of the game is to throw the ball into the opposing team's net, while defenders attempt to block it with their bodies. The indoor court has tactile lines to assist players with their orientation on court and the ball must make contact with certain areas of the court during the game.