Why do football players wear eye black?

(WHTM) — Eye black is one of the most common accessories football players wear during games, but not everyone knows why.

The belief is that eye back can reduce how much glare reaches a player's eyes, Mental Floss explains. Since the color black is able to absorb most light frequencies, the theory is that it can absorb excessive light appearing in our peripheral vision, thereby increasing contrast on the things players are looking at.

There have been multiple studies conducted on the effectiveness of eye black which have produced varying results, the outlet reports. However, experts agree eye black made of beeswax, paraffin, and carbon can "reduce glare and improve contrast sensitivity."

"Certainly in football and baseball, where tracking a ball at high speed is an important aspect, any competitive advantage could be beneficial," Dr. Brian M. DeBroff, the lead author of a Yale study on the product, told The New York Times in 2006.

Anti-glare stickers and petroleum jelly, also frequently used to reduce glare, were found to have no impact, according to Mental Floss.

Athletes in many sports wear eye black to some degree, including Philadelphia Eagles quarterback Jalen Hurts. Some players wear eye black for its protective measures, while others use it as aesthetic accessories, such as writing messages or smearing it on their faces for intimidation or superstition.

“I thought we would find it to be like war paint and a psychological advantage more than anything else,” DeBroff said. “We were surprised to find a benefit from the grease.”

DeBroff's study showed that among the first to use eye black was Washington football player Andy Farkas in 1942. Some have also claimed that, even earlier, New York Yankees great Babe Ruth was using grease that contained beeswax, paraffin, and carbon soot.

Players continue to use eye black today, however some changed their facial accessories to eye black stickers, which are easier to apply, offer similar benefits, and leave less residue.