It might seem odd to think of exercises your eyes, but direct training of vision skills has become a real staple in professional ice hockey.
The NHL website has an article about Michael Cordon (Pittsburgh Penguins, formerly Montreal Canadians) and Eddie Lack (Carolina Hurricanes) that discusses eye training.
Sadly, it's a bit light on specifics beyond testing and doing ball and juggling drills, but it's interesting in and of itself as a concept.
Goaltenders pass the eye test
I have to wonder about how much this will eventually spill over into youth sports, and then, into the general population. Improving visual acuity would have benefits for driving, flying, avoiding vehicles, etc., never mind stopping pucks for a living.