The state-supported campus in Fremont is one of three American schools
for the blind that recently began teaching adapted tennis, which was
invented in Japan in the 1980s. A nonprofit group called Tennis Serves is working to promote the sport throughout the U.S. Players use a foam ball filled with metal beads that rattle on impact,
allowing them to locate the ball when it hits the ground or racket. Once
served, they have to return the ball before it bounces three times.