Keep Your Eye On The Ball!
When he was three or four, I was trying to get my son to play catch with a baseball. His eyes wandered all over the place and he constantly missed the ball and had to chase after it. "If your going to catch it, you have to keep your eye on the ball", I instructed. He looked confused for a moment, then he took the ball and planted firmly over his eye. "Like this?", he asked.