A new study published in Evolutionary Psychological Science has found that limbal rings — the dark circles that surround the colored part of the eye — make men’s faces appear healthier to women, but not necessarily more attractive. The research, which used carefully controlled facial images, helps clarify why past studies have reported mixed results about the role limbal rings play in physical attraction.
The study was designed to address a puzzle in previous findings. While some studies have suggested that limbal rings boost a man’s attractiveness, others have shown no such effect. One possibility is that differences in the attractiveness of the faces used in those studies may have obscured the influence of limbal rings. The research team wanted to find out whether limbal rings make a bigger difference when the face is already attractive, or if their influence is consistent regardless of how good-looking the person is overall.
“Many areas of psychology are interested in how people perceive other people, and our first perceptions of each other are formed when immediately seeing each other,” said study author Matthew C. Howard, an associate professor and interim chair for the Department of Marketing, Supply Chain Management, and Analytics at The University of South Alabama.
“Our minds subconsciously target specific cues whenever we meet people to form initial assessments, and people dedicate a significant amount of attention to eyes when meeting others. Understanding perceptions of eyes, specially, can produce significant knowledge as to how and why people form broader perceptions and opinions about people, causing this area of research to be particularly important.”
To explore this, Howard and his co-author, Mitch Brown, created a set of facial images using photos from a standardized image library called the Chicago Face Database. They selected 20 male faces—10 rated as highly attractive and 10 rated as unattractive—based on previous evaluations. Using image editing software, they modified each face to create two versions: one with clearly visible limbal rings and one without. This gave them a total of 40 facial images, systematically varying both attractiveness and limbal ring presence.
“This area of research is fun,” Howard remarked. “To conduct this study, we photoshopped photographs to determine whether altering the eyes systematically changed perceptions of the people in those photographs. So, this study integrated both science and art to test psychological theory.”
The study involved 149 women between the ages of 18 and 30 who identified as sexually attracted to men and identified as White. All participants viewed the 40 facial images, presented in random order, and rated each face on two scales: how healthy the person appeared, and how attractive they found the person. Each face was evaluated independently on both qualities.
When the researchers analyzed the results, they found clear evidence that people perceived more attractive faces as both healthier and more attractive than less attractive ones. This was expected. But when it came to limbal rings, the results were more specific. Faces with limbal rings were rated as slightly healthier than those without, regardless of whether the faces were attractive or not. However, limbal rings did not have any noticeable effect on how attractive the faces were judged to be.
“The effects for basic attractiveness did not replicate from previous stimulus sets,” Brown, an instructor of psychological science at the University of Arkansas, told PsyPost. “That is, perceivers did not evaluate faces with limbal rings as more attractive than those without.”
This finding suggests that limbal rings do carry a signal about health, which people seem to pick up on—even without being consciously aware of it. But the rings themselves don’t appear to boost overall attractiveness, at least not in the absence of other factors.
The researchers also tested whether the effects of limbal rings were stronger when the face was already attractive. Some evolutionary theories suggest that physical traits linked to health—like limbal rings—should matter more in short-term mating situations, where people tend to focus more on physical appearance. Because attractive faces are more likely to be associated with short-term romantic interest, the researchers predicted that limbal rings might have a stronger effect on those faces.
But the results didn’t support this idea. Limbal rings increased perceived health, but this effect was steady across both attractive and unattractive faces. There was no sign that attractiveness changed how much people paid attention to limbal rings.
“While considering different types of stimuli than those previously used in limbal rings studies, we find continued evidence for a perceived advantage in faces with limbal rings in appearing healthier,” Brown explained. “This effect was one again for male targets and female perceivers. Importantly, we find evidence that this effect is independent of attractiveness in faces. On a theoretical level, readers should know that limbal rings can reliably influence perceptions of health.”
As with all research, there are some limitations. One is that the faces all came from a specific image database, which may not reflect the full range of real-world appearances. Also, the study focused on a single demographic group: White women rating White men. It remains to be seen whether these findings hold up with different age groups, racial backgrounds, or sexual orientations.
Another issue is that the effect of limbal rings may depend on more than just facial attractiveness. Other features—like eye size, scleral brightness (the whiteness of the eye), or emotional expression—could interact with limbal rings to influence perceptions. These weren’t tested in the current study, but they represent important areas for future research.
The researchers also note that previous studies used different techniques to add limbal rings to images, which may have affected how natural the rings looked. For example, some earlier work used a more gradual shading approach, while this study used a crisp, dark line. It’s possible that differences in how the limbal rings are presented could affect how people respond to them. Future work could compare these methods directly.
“This is a story of stimulus sets and the various limitations that emerge from each one,” Brown said. “The original stimulus sets showed effects for limbal rings were rated as more attractive (Brown & Sacco, 2018; Peshek et al., 2011), which could have been amplified by the faces being relatively more attractive overall. Conversely, the faces in the current study (i.e., from the Chicago Faces Database; Ma et al., 2015) did not have the same level of attractiveness, with several faces being rated as middlingly attractive at best. It could be possible that the signal value of limbal rings as attractive is apparent but the range of attractiveness in stimuli could limit much of future research.”
Finally, while the study didn’t find that limbal rings increased attractiveness, it doesn’t mean they never do. Past research has shown that people become more sensitive to health cues when they are primed to think about short-term mating, such as imagining a casual sexual encounter. This study didn’t include such a prime. It’s possible that limbal rings might boost attractiveness when people are already in a mindset that values short-term mating. The researchers suggest that more immersive experimental setups—such as videos or vivid scenarios—may be needed to activate this effect.
In short, this study supports the idea that limbal rings signal health, but casts doubt on the idea that they always make faces more attractive. The health effect seems to be consistent, but the attractiveness effect may be more sensitive to context. The work adds clarity to a growing body of research on the subtle visual cues people use when making quick social judgments—especially in the context of romantic or sexual attraction.
There’s still much to learn about how people process eye features when sizing up potential mates or forming impressions. Eyes are among the most attention-grabbing parts of the face, and features like limbal rings may influence our social perceptions in ways we’re not fully aware of.
“There is so much still yet to be discovered about which aspects of the eyes influence interpersonal perceptions and why,” Howard said. “Making these discoveries can help understand why we naturally (dis)like certain people, why we (dis)trust certain people, and why we are (un)attracted to certain people. In other words, it has significant implications for all types of social interactions.”
“With perceivers reliably using limbal rings as part of their heuristics in mating decisions, it would be important to consider whether limbal rings reflect a kernel of truth in their heuristics,” Brown added. “We are interested in understanding the actual health of people with varying visibility of limbal rings with special consideration for chronic health. In a sense, are limbal rings a visual telomere? This could lead us to address the reproductive and sexual success of people as a function of their limbal ring visibility in addition to their preferred sexual strategies based on self-perceptions of their ability to navigate short-term mating markets.”
The study, “Investigating Potential Interactive Effects Between Limbal Rings and Facial Attractiveness,” was published on October 24, 2024.