Maybe fantasy baseball scouting will start to list eye color along with which side players bat from and how their home park is configured - lighter-colored eyes, it seems, don't absorb light the way darker eyes do, and in a precisely game like baseball where milliseconds matter, the impact can be substantial.

The clarity of a player's vision, called visual acuity, is not the only important quality to track for baseball players. So is contrast sensitivity.  Dr. Keith Smithson, the team optometrist for the Washington Wizards, Washington Nationals and D.C. United, measures this in order to interpret "a ball player's ability to pick out a white target, a baseball, against different backgrounds."

 Texas Rangers outfielder Josh Hamilton hasn't had much trouble slugging like an All-Star during night games this season, but has struggled mightily during day games, exaggerating a career-long trend. When he blamed his blue eyes and light sensitivity for the discrepancy, media reports quickly examined the statistics of other light-eyed players and found little difference between most batters' performances in day and night games. But according to some vision experts, there are legitimate reasons why a player might hit worse under the sun than under the lights.

Optometrists say that afternoon games played under bright and sunny skies can make hitting difficult for certain light-sensitive players - Chris Gorski, Inside Science News Service