FREMONT, Calif. -

Learning how to play tennis is hard enough. Now try it when you can't see.
      That's what students are doing at the California School for the Blind. They're learning a form of tennis adapted for the visually impaired.
      The state-supported campus in Fremont, Calif., 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.
      Blind tennis features a smaller court, lower net and junior tennis rackets with bigger heads and shorter handles.
      Players use a foam ball filled with metal beads that rattle on impact, allowing them to hear and locate the ball when it hits the ground or racket.