New research suggests that people with a dark ring around the iris of their eyes are perceived to be more attractive because they appear healthier.

The study, published in Personality and Social Psychology Bulletin, investigated how limbal rings affect our first impressions of a person.

“I initially was drawn to the topic of limbal rings 4 years ago when I became interested in some of the more subtle facial features implicated in facial attractiveness. I stumbled on an article from Darren Peshek about limbal rings where he found that these little rings around people’s irises made them appear more attractive,” explained study author Mitch Brown of the University of Southern Mississippi.

“He provided me the faces with and without limbal rings and I started conducting studies using them. As far as this particular line of research, though, I wanted to understand why limbal rings were considered attractive, which led me to consider their role as a potential health cue,” Brown said. “I conducted an initial experiment to see how they communicate health and I eventually developed a program of research that implicates their attractiveness in a short-term mating domain.”

In the three-part study, the participants viewed and rated a series of faces — some of which had limbal rings.

The researchers found that faces with limbal rings tended to viewed as healthier than those without limbal rings, particularly when it was women rating a male face. They also found that women viewed male faces with limbal rings as more desirable short-term mates.

“Very subtle facial features are able to communicate a wealth of information and certain portions of our perceptions and behaviors can be influenced by these subtle cues,” Brown told PsyPost. “More specifically, people should think about limbal rings as a cue to short-term mate quality through its ability to communicate health. Even further, this work suggests that women are especially sensitive to these facial differences.”

Limbal rings become less defined as our health declines and as we age.

“Two major caveats exist in this program of research,” Brown remarked. “First, broadly, these are only one of many fitness indicators in a face and it appears limited to communicating cardiovascular health, whereas symmetry would communicate immunocompetence and masculinized features would connote developmentally appropriate testosterone; one feature cannot communicate everything, rather it’s a combination of different features to create the overall picture.

“The second is that limbal rings may not necessarily make individuals appear more attractive, as evidenced by the mean differences in my second and third experiments in the paper, but they provide buffers from derogation when women are especially interested in short-term mating,” he continued.

“For future directions, we are looking at how limbal rings can predict various mating behaviors and perceptual responses. We have just collected and analyzed data this week suggesting an avoidance response toward faces without limbal rings when short-term mating is salient.”

“Take a look in the mirror and check to see if you have a dark ring around your iris,” Brown added. “Then, look at your friends’ eyes. Congratulations, you’re going to spend the next few years checking for limbal rings in everyone you meet!”

The study, “Put a (Limbal) Ring on It: Women Perceive Men’s Limbal Rings as a Health Cue in Short-Term Mating Domains“, was also co-authored by Donald F. Sacco.