I'd like to see a study of major league hitters hitting on sunny days, overcast days, and under the lights -- then separate that data by stadium and by month -- before I'd want to see any data breakdown by player characteristics.

Given how good illumination is at most major league ball parks these days, I would think picking up the spin of the ball when it has a decidedly sharp shadow on it has to be tougher than muted illumination of an overcast day or the surrounding illumination of artificial light. Everyone already knows anecdotally it is harder to hit in the twilight that is aided by a stadium shadow that keeps the pitcher in the light and the batter in the shade, or vice versa.

The breakdown by stadium and by month would help eliminate anomalies such as how a ball tends to carry. Once enough data is gathered, then one can do a study by genetic component whether it's eye color, player height, skin color, whatever.

Eye color may have an effect on certain things but in this day of sports lenses, I have to wonder even if the optometrist is generally correct, we're not left with a so-what situation. I wear two different sunglasses for tennis depending on conditions, and will someday get a third.

Besides, just because an optometrist says something doesn't mean that optometrist has conducted or is well versed in clinical trials. If we're just dealing with stated contentions, it is my contention most people regardless of eye color have more trouble hitting in the daytime than at night. Until I see empirical data otherwise, I am unanimous in that contention.

Wonder what the root cause is. I'm guessing because people with blue eyes in general have a harder time in bright light than those with darker eyes. I don't know enough about the physiology of the eye to hazard a guess as to why, though.

Would shaded contacts or lightly tinted glasses make a difference when hitting during the day?

Interestingly enough, blue eyed Cal Ripken was a better hitter in the daytime than at night. But, hey, that's only one player

Just curious, but what did blue-eyed ballplayers who played prior to night games being common do? Would be interesting to know how many HOF'ers who played all or most of their careers prior to 1940 had blue eyes?

I have green eyes and only played amateur and a little semi-pro ball in my younger days. I did, however, have the opportunity to play "under the lights" on several occasions and, as far as batting, I preferred it. I could see the ball better and pick it a tad sooner in the pitcher's hand. Always seemed to get an extra hit or walk or two playing night games over daytime games.

Later in life, due to employment, I had to have extensive vision tests to maintain certain qualifications especially since 3/4 of my work life was spent working at night and in low light situations. I was told I had excellent "night vision" due to having more "cones" (whatever they are) then most and as I aged I would lose my "night vision" (which has been the case) as the amount of those "cones" decreased.

Eye color was never mentioned so I don't know what part that plays but I do know there are people who seem to see better in low light situations then others.

I understand that there is some data to support the fact that brown eyed left handed hitters hit better on friday night's off blue eyed right handed pitchers who were born in the month of June, whose mother's nickname was maggie, and whose dog was named fluffy.