Kellar, the English Springer spaniel, was born blind. can’t see the ball, but he can find it and bring it back! He plays fetch completely by ear. He can hear (or feel) the ball hit the ground, and then its a matter of following directions. From the YouTube page:
Kellar was originally trained to play ball with the commands "hot" and "cold". We later added "warmer", "passed it", "left" and "right". The process took about a week for the basic commands.
That’s a good dog. Visit Kellar at his Facebook page. (via The Chive)