Eye black

Eye black is a grease or strip applied under the eyes to reduce glare. It is often used by American football, baseball, and lacrosse players, where sunlight or stadium lights can impair seeing an airborne ball.

It is a form of functional makeup.

One of the earliest known instances of a player wearing eye black is baseball legend Babe Ruth, who, in or around the 1930s, used the grease in an attempt to reduce sun glare. According to Paul Lukas of ESPN.com, eye black caught on with American football player Andy Farkas. He also states that the original eye black was made from burned cork ashes.

A 2003 study by Brian DeBroff and Patricia Pahk tested whether black eye grease actually had anti-glare properties. The subjects of the study were divided into three groups: wearers of eye black, wearers of anti-glare stickers, and wearers of petroleum jelly. The subjects' vision was tested using an eye chart while being exposed to natural sunlight.

The study concluded that eye black reduced glare of the sun and improved contrast sensitivity, whereas commercial anti-glare stickers and petroleum jelly (the control substance) were found to be ineffective.

However, the study was subject to unavoidable demand bias, wherein the test subjects could have unconsciously changed their responses during testing based on the fact that they knew which substance they were wearing. Also, the petroleum jelly could have introduced glare that would not occur on natural skin and the study did not test a control condition of natural skin. Learning bias is also a factor in the results due to chart repetition.

A study by Benjamin R. Powers at University of New Hampshire, which improved on DeBroff's methodology, found eye black to reduce glare from the sun in females and in those whose eye-color was not blue. The study also tested males and blue-eyed subjects. However, the results were not statistically significant (probably due to a smaller sample size of those test subjects). Some testing was also performed indoors under artificial lighting (when inclement weather prohibited outdoor testing). However, those results showed little difference and were not statistically significant. The Powers study was not a double-blind study because those in contact with the test subjects knew which substance was applied. Also, the eye tests were performed at a distance of only 1.15 meters.

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