Bryce Harper, the Washington Nationals outfielder, created a minor stir last week when he showed up in the dugout wearing reddish tinted contact lenses.
It was not an attempt to coordinate his eyes with his uniform. The lenses are supposed to reduce glare and enhance contrast so that the seams on a baseball, for instance, are easier to spot.
Other players have experimented with the amber-coloured lenses, including Josh Hamilton of the Texas Rangers, who tried them last year hoping they would improve his batting average. He soon gave them up, saying they harmed his depth perception.
To some scientists, that may not be a surprise. Research on tinted lenses has not backed the claim that they improve visual or athletic performance. In a 2007 study in the journal Optometry, 35 college and professional football players were given the task of identifying a series of curved lines that blended into a blurry background. The players tried the experiment with clear lenses, and then repeated it with amber-coloured lenses.
Although the coloured lenses created slight improvements in contrast, the effect was not clinically significant, said Eric Porisch, an optometrist and the author of the study.
Another study, by Spanish researchers in 2008, looked at the effect that tinted lenses had on glare in outdoor sports. Subjects wore a coloured lens in one eye and a clear contact in the other. After repeated measurements, the researchers found no clinically significant benefit from the coloured lenses.
Other studies have had similar results, with one from 2009 suggesting that the lenses may actually worsen contrast sensitivity.
The verdict
Most research has not found that coloured contact lenses improve athletic performance.
It was not an attempt to coordinate his eyes with his uniform. The lenses are supposed to reduce glare and enhance contrast so that the seams on a baseball, for instance, are easier to spot.
Other players have experimented with the amber-coloured lenses, including Josh Hamilton of the Texas Rangers, who tried them last year hoping they would improve his batting average. He soon gave them up, saying they harmed his depth perception.
To some scientists, that may not be a surprise. Research on tinted lenses has not backed the claim that they improve visual or athletic performance. In a 2007 study in the journal Optometry, 35 college and professional football players were given the task of identifying a series of curved lines that blended into a blurry background. The players tried the experiment with clear lenses, and then repeated it with amber-coloured lenses.
Although the coloured lenses created slight improvements in contrast, the effect was not clinically significant, said Eric Porisch, an optometrist and the author of the study.
Another study, by Spanish researchers in 2008, looked at the effect that tinted lenses had on glare in outdoor sports. Subjects wore a coloured lens in one eye and a clear contact in the other. After repeated measurements, the researchers found no clinically significant benefit from the coloured lenses.
Other studies have had similar results, with one from 2009 suggesting that the lenses may actually worsen contrast sensitivity.
The verdict
Most research has not found that coloured contact lenses improve athletic performance.