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Why do baseball players put a black mark under their eyes? – Althea, age 9, Edmonton, Alberta
Bottom of the ninth. Two outs. Bases loaded. The winning run is standing on third base. The pitcher winds up and throws. The batter swings and sends a high fly ball into the air. The center fielder races back, looks up at the sky and then says the sentence no baseball fan wants to hear: “I lost it in the sun.”
For baseball players, seeing the ball clearly can be the difference between making a game-winning catch and watching the winning run score. That is one reason many athletes put black marks under their eyes before a game.
Baseball, football and other outdoor athletes apply black stripes under their eyes because they hope it might reduce the glare from the sun or bright stadium lights. But the use of eye black comes down to tradition as much as it does science.
As an athletic trainer and professor who studies sports medicine and performance, I spend a lot of time thinking about how details like vision, sunlight and confidence can affect the way athletes play.
Eye black is usually made from black grease or black stickers placed underneath the eyes. The idea is simple: Bright light from the sun or stadium lights can bounce off a player’s cheeks into their eyes. The black color absorbs some of that light instead of reflecting it, which may help reduce glare.
The practice of using eye black has been around for a long time. Some stories say Babe Ruth used burned cork under his eyes. Football players may have been experimenting with it more than 100 years ago. By the mid-1900s, those black marks had become a familiar part of outdoor sports.
Scientists have tested whether eye black actually works. In one study, black grease helped reduce glare a little and improved something called contrast sensitivity. That means it may help your eyes notice the difference between an object and its background, like a white baseball against a bright blue sky or a bank of stadium lights.
But the research is not totally settled. Another study found that the benefit may be small and can depend on how the test is done.
So eye black probably does not give players superhero vision. But in a sport where a hard-hit ball can travel more than 95 mph, even a potential tiny visual advantage can feel worth trying.
Eye black is not the only way athletes fight glare. Baseball hats help shade players’ eyes. Skiers wear goggles because snow can reflect sunlight like a mirror. Race car drivers use tinted helmet shields, and some athletes wear sunglasses, tinted visors or tinted contact lenses outdoors.
If eye black helps only a little with glare, you might wonder why baseball players do not all wear sunglasses instead.
Some do wear sunglasses during games, especially outfielders. But not every player likes them.
In a fast game, players need to track the ball quickly and feel comfortable while they play. Sunglasses can fog, slide down, collect sweat or slightly change how the ball looks. Some players like sunglasses. Some would prefer not to have anything extra on their face. Others feel more comfortable relying on their own eyes, a baseball hat and a little eye black.
Eye black is not a secret weapon. It is more like one small tool from an athlete’s glare-fighting utility belt.
If science suggests eye black only helps a little, then why do so many players still wear it?
The answer is not just about eyeballs. It is also about routine.
Baseball is famous for routines and superstitions. Some players eat the same meal before every game. Others always put on their equipment in the same order or avoid stepping on the foul line.
Sports psychologists have researched how routines can help athletes prepare for performance. A 2021 study on preperformance routines found that routines before competition can help athletes improve focus, manage emotions, get ready to compete and perform better under pressure.
Eye black eventually became part of that routine for many athletes. Over time, it also became part of the look of baseball and football. Some players wear simple black lines. Others use stickers with messages, crosses, flags or team slogans.
The next time you see black marks under a player’s eyes, you’ll know that it’s not there just to look tough. They are trying to see the ball, block the glare and feel confident for the next big play.
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This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Adam Annaccone, University of Texas at Arlington
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Adam Annaccone does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
