Have you ever wondered if you should be using eye black on those bright, sunny North Carolina afternoons? The short answer, according to Dr. Brian M. DeBroff, the lead author of a Yale study on the subject, it doesn’t hurt.
Eye Black Studies
There have been a few different eye-black studies done over the past 20 years, including one by the University of New Hampshire and one by Yale University. Although these two studies (and most of the others) began with significant skepticism, and have all shown slightly different results, they have agreed that traditional eye grease made of beeswax, paraffin, and carbon does actually reduce glare and improve contrast sensitivity.
The testing took place using the the Pelli Robson contrast sensitivity chart, which you have probably never heard of, but as you can see, the chart has different gradients of contrast.
Blue Eyes vs. Non-Blue Eyes
Some of the details are also interesting. For participants with non-blue eyes, eye black provided a significant advantage in terms of contrast sensitivity.
That was not the case for blue-eyed individuals. There was a marked difference in the effect of eye black on those with blue versus non-blue eyes. This may be an example of the operation of Weber’s Law of Just Noticeable Differences, or JNDs. This law states that for a change in intensity to be noticeable, the change must be proportional to the original intensity.
In the case of glare arising from the cheek, its effect in reducing contrast is proportional to the existing level of ambient glare. Blue-eyed individuals, because they have less iris pigment to screen out unwanted light, have a greater level of intraocular scatter (light reflected within the eye) than non-blue-eyed people. Thus, for blue-eyed individuals, glare arising from the cheek should be less detectable than for individuals with darker irises.
If glare is less detectable for the former, then eliminating or reducing it with eye black will have less of an effect than if the glare were more detectable, as is the case for non-blue-eyed people.
Eye Black Stickers
If you like the stickers with the team logos, the studies concluded that anti-glare stickers and petroleum jelly have zero impact.
The studies indicate that wearing eye black can improve contrast sensitivity, presumably by reducing glare. This provides a potential advantage for those who participate in athletic activities. It remains to be seen, however, whether the small effect (one letter set of improvement in contrast sensitivity on a Pelli-Robson chart) translates to actual improvement in performance on the playing field.
Buy Some Eye Black
You can find eye black at almost any sporting goods store, but if you want to support CNCMSBL you can use this affiliate link that will earn a few cents for the league.
Easton’s eye black reduces glare from the sun or stadium lights. Comes in an easy-to-use applicator which prevents a mess. The non-bleed formula washes off easily with soap and water.