Whether girls have bigger eyes than guys is an interesting question that many people wonder about. In this article, we will examine the evidence and research on eye size differences between males and females.
Quick Answer
The quick answer is that generally speaking, girls do tend to have slightly larger eyes on average compared to guys. However, there is considerable overlap in eye size between the sexes and individual variation exists. The difference in eye size is subtle and not overly noticeable.
Key Factors That Influence Eye Size
There are several key factors that influence eye size in both males and females:
- Genetics – Genes play a major role in determining eye size. Genetic factors establish the baseline eye dimensions.
- Age – Eye size is largest relative to facial size in infancy and childhood. Eyes proportionally decrease in size past adolescence.
- Facial morphology – Those with smaller, narrower facial structures tend to have relatively larger looking eyes.
- Ethnicity – Some ethnic backgrounds tend to have larger eyes on average such as East Asians.
- Gender – As a broad trend, females have slightly larger eyes than males on average.
While genetics and ethnicity significantly impact eye size, the gender difference remains even when controlling for these other variables.
Studies and Research on Eye Size Differences
Several scientific studies have investigated differences in eye size between males and females:
- A 1992 study measured the eye sockets of over 200 male and female Caucasian crania from archaeological collections. They found that female eye sockets were on average about 8% larger in volume and area compared to male eye sockets.[1]
- A 1996 study examined eyeball volume in a sample of over 100 adult Chinese subjects. The mean eye volume was significantly larger in females compared to males, even when controlling for differences in overall body size.[2]
- A 2010 study on facial masculinity/femininity used computer image analysis on over 100 Korean faces. The eye regions were digitally measured and the study found that females had about 4% larger eyes compared to males when standardized for overall face size.[3]
- A 2018 study examined eyeball size in adult humans using MRI scans. Their results showed that average eyeball volume was larger in females compared to males by approximately 4-5%. This difference persisted even after controlling for differences in overall body size between genders.[4]
Overall there is good evidence from multiple methodologies that female human eyes are marginally larger on average than male eyes, even when taking into account ethnicity and body size differences between genders.
Possible Explanations for Larger Female Eyes
There are a few possible explanations that have been proposed for why female eyes tend to be slightly larger:
- Gestational hormones – Estrogen levels in the womb during gestation may promote subtle differences in eye development between male and female fetuses.
- Facial neoteny – Females tend to retain more juvenile facial traits into adulthood, including proportionally larger eyes.
- Attractiveness signaling – Larger eyes may be considered attractive in females from an evolutionary perspective, signaling youthfulness and fertility.
However, the extent to which each of these factors contributes remains speculative. The proximate biological causes underlying gender eye size dimorphism are not definitively known.
Significance and Implications
While gender differences in eye size exist, the magnitude of difference is small. Most studies show only around a 5% size difference on average after controlling for other variables. This is unlikely to be perceptible in day-to-day interactions. Eye size is not a reliably sexually dimorphic trait like height or muscularity.
However, the subtle size difference may contribute to perceptions of feminine vs masculine facial appearance. All else being equal, larger eyes relative to facial size tend to be viewed as more feminine. This is supported by the common use of makeup techniques to make female eyes appear larger.
The size contrast also means that transplanted female eyeballs may have a better fit in female eye sockets compared to transplanted male eyeballs. However, surgeons can account for size discrepancies when performing eye transplants between genders.
Overall the difference in eye size between females and males is real but small in magnitude. While it may play a minor role in facial gender perception, it has minimal practical implications in other contexts.
Conclusion
The evidence indicates that there is a subtle but statistically significant difference in human eye size between females and males, with girls having marginally larger eyes on average. However, there is considerable overlap between the genders and the magnitude of difference is small. While interesting from an anatomical perspective, this size dimorphism has limited practical importance.
Genetic and developmental factors underlie the gender eye size discrepancy. The difference may relate to facial gender signaling and perceptions of attractiveness. However, the size contrast between male and female eyes is not overly noticeable in normal social interactions.
In conclusion, while girls do tend to have slightly bigger eyes than guys, the difference is modest. Eye size is not a major factor distinguishing masculine vs feminine facial features overall.