The distinct eye shape of Asians, often described as “almond-shaped” or “monolid,” is one of the most recognizable facial features that sets East Asians apart from other ethnic groups. However, the reason behind this phenotypic trait is complex, involving genetics, evolutionary history, and environmental factors. Epicanthal folds are present in about half the Asian population. Asymmetrical eyes, uneven eyes, or one eye lower than the other are common situations among people of Asian descent. One of the causes of double eyelid asymmetry is the levator muscle. This is an eyelid muscle that helps to elevate the eyelid.
The Evolutionary History Behind Asian Eyes
The epicanthic fold, which is the medical term for the skin fold across the inner corner of the eye covering the upper eyelid crease, is prevalent in populations from East Asia, Southeast Asia, Central Asia, and some groups in South Asia.
This morphological feature is thought to have evolved among ancestral East Asians as an evolutionary adaptation against the cold, dry climate of the Eurasian steppe and the glare from snowy landscapes. If you’re curious about the physical characteristics of East Asians, you might discover why are asian eyes slanted, which is believed to be another adaptation to this environment.
Several theories have been proposed regarding the evolutionary advantage of the epicanthic fold:
- Cold climate adaptation – The fold protected frostbite and snow blindness in the harsh frigid environment of Ice Age Siberia, where ancestral East Asians are believed to have lived during the Upper Paleolithic period. The extra skin over the eye shielded it against the cold and wind.
- UV radiation protection – The epicanthic fold filters out excessive UV radiation, protecting against radiation damage. This offered an advantage in the higher UV levels of plateau regions.
- Enhanced glare reduction – By narrowing the eye opening, the fold reduced glare from sunlight reflection off snow and bodies of water. This improved visual acuity.
- Improved eyeball humidification – The extra skin over the eye may have helped maintain moisture and protect against dryness in cold, windy steppe regions. The fold traps tears to keep the eye lubricated.
The epicanthic fold likely provided a combination of these benefits for early Eurasian hunter-gatherer groups struggling to survive in harsh environments during the last ice age. The advantageous traits were passed down to subsequent generations.
Genetic Basis of Asian Eye Shape
Studies have uncovered certain genetic mutations associated with the development of epicanthic folds and monolids in East Asian populations:
- EDAR gene – The EDAR V370A variation arose about 30,000 years ago in early East Asians and affects jaw shape, hair thickness, sweat glands, and tooth morphology. It also impacts craniofacial development including eye shape.
- PAX3 gene – Variants of this gene are linked to epicanthus formation. PAX3 is involved in neural crest cell migration during embryonic development which impacts eye, ear, and face formation.
- HERC2 gene – Certain mutations in this gene which affects eye and skin pigmentation are nearly universal among East Asians and believed to be a major driver of monolids.
- ABCC11 gene – This gene determines earwax type as well as sweat gland density. The East Asian variant codes for reduced sweat glands, which researchers suggest may have coevolved with the epicanthic fold.
- SPAG5 gene – Associated with skin elasticity and eyelid traits including single upper eyelids. Common in East Asians but rare in other groups.
These are some of the major genetic differences that contribute to the common eye phenotypes seen among Asians but not in those of European or African descent. The mutations arose from evolution in cold, UV-intense environments and were likely preserved due to benefits of the epicanthic fold.
Environmental and Developmental Factors
Genetics are not the only influence behind the distinct eyes of Asians. External factors during prenatal and postnatal development also play a role:
- Intrauterine position – Some studies indicate that fetal position in the uterus may impact eye shape. This is influenced by number of fetuses and available space.
- Eyelid development – During gestation, the eyes develop from folds of surface ectoderm. Environmental factors in the womb may disrupt normal fusion of eyelid folds.
- Facial fat distribution – Compared to Caucasians, Asians tend to have more fat deposits around the eye area which accentuate the upper eyelid fold.
- Face and eye socket structure – Asians tend to have flatter and broader facial bone structure including the orbitals and nasal bones, which affects appearance of eyes.
- Eye opening – Many Asians develop a supratarsal crease (double eyelid) with growth and age as connective tissue relaxes and fat deposits increase above the tarsal plate.
- Climate – Drier conditions and more indoor heating tends to make eyelid skin thicker and saggy. More exposure to arid climates may exacerbate monolids in Asia.
Both nurture and nature shape the stereotypical eyes of Asians. While genes play a foundational role, environmental factors in the womb and during maturation also contribute to this signature facial characteristic.
Is the Epicanthic Fold Really Just an “Asian” Trait?
While epicanthic folds and monolids are undeniably associated with Asians, particularly East Asians and Southeast Asians, it’s an oversimplification to label them as an exclusively “Asian trait.”
In reality, epicanthic folds and single eyelids occur at varying frequencies in different ethnic groups around the world:
- Indigenous Americans – Common among Inuit, Yupik, and Aleut people inhabiting Arctic climes. Also seen in some Na-Dené groups like Athabaskans.
- Central Asians – Prevalent among Turkic groups like Uzbeks and Kazakhs, Mongolic groups, Tungusic peoples, Siberians, and Kyrgyz.
- South Asians – Occurs among Burusho, Tajiks, Uyghurs, Hui, and in isolated tribes in the Himalayan region.
- Middle Easterners – Sometimes present in Bedouin people as well as groups in Iran, Afghanistan, Pakistan and North India.
- Eastern Europeans – Sporadically observed in groups like Chukchi, Eskimos, Koryaks, Itelmen, and certain Siberian ethnicities.
- Africans – Occasionally seen in some Cushitic-speaking groups in Ethiopia such as Oromo and Somali. Also Nilotic tribes like Kalenjin and Masai.
- Circumpolar groups – Common trait among Inuit and Yupik people in Arctic regions ranging from Siberia, Alaska, Greenland to Canada.
So while strongly associated with East Asians, single eyelids and eye folds occur at lower frequencies among diverse ethnicities living incold, dry climates around the world. It represents convergent evolution of adaptive traits to similar environmental pressures.
Monolid vs Double Eyelid Eyes
Two main types of Asian eyes are commonly referenced:
Monolids refer to eyes with either an absent or very faint upper eyelid crease that hides the supratarsal fold. This gives the appearance of a single continuous eyelid. Most East and Southeast Asians possess this eye shape.
Double eyelids have a visible crease that separates the outer eyelid from the supraorbital margin formed by a supratarsal fold. Double lids are common in other races but also occur in many Asians either congenitally or developed with age.
Monolids are sometimes referred to as single eyelids, while double eyelids are also known as European eyes. However, it’s important to note that many Westerners also naturally have hooded eyes or mono eyelids, while a lot of Asians are born with double lids or gain them over time.
Why the Crease Matters
The presence or absence of an upper eye crease impacts perceived attractiveness and expressiveness of eyes. This helps explain the popularity of eyelid surgery to create creases in Asia.
Some reasons the crease is considered desirable:
- Creates bigger, rounder looking eyes compared to narrow monolids
- Allows more expression through exposure of upper eyelid skin
- Increased variety of makeup looks and techniques
- Deemed by many as more aesthetically pleasing
- Gives eyes a more “awakened” look
- Sign of maturity as creases often develop with age
- Perceived as more feminine
- Associated with Western beauty standards
The crease essentially enables more visible sclera above the iris, creating a bigger-looking, more expressive eye. However, diversity advocates are pushing back against monolid stigma.
Is Epicanthoplasty Ethical?
Epicanthoplasty, also known as double eyelid surgery, is a procedure to create upper eye creases that are absent or poorly defined in Asians. It has grown enormously popular in East Asia and for Asian-Americans. However, there is debate over the ethics of surgically altering ethnic features.
Arguments Against:
- Promotes Eurocentric beauty ideals over ethnic pride
- Unnecessary cosmetic surgery reinforces racial insecurity
- Risks of complication from surgery outweigh questionable benefits
- Form of ethnoplasty that perpetuates racial hierarchies
- Motivated by desire for Westernized features
Arguments For:
- Personal freedom and autonomy over one’s body
- Procedure has health benefits like expanding visual field
- Improves self-esteem and confidence
- Makes eyes more expressive, easier to apply makeup
- Ethnicity not only consideration – preference matters
- Allows people to harmonize facial features
There are merits to both sides of this complex debate. Individuals should thoughtfully weigh the risks and motivations before undergoing any permanent elective procedure.
Double Eyelid Tape & Glue
Non-surgical methods to temporarily create the illusion of ocular creases have also proven extremely popular. These provide affordable, non-invasive options for special events and photos.
Tapes use adhesive strips applied along the lash line to press against the mobile eyelid skin, forcing it upward. While effective for several hours, these can cause skin irritation.
Glues contain non-toxic medical-grade adhesives to lift and adhere the upper lid to the brow bone. These create a more natural look but take practice to apply properly so skin isn’t pulled.
Both tapes and glues employ the same mechanism for artificially forming temporary creases. They provide accessible alternatives to blepharoplasty but aren’t suitable for regular long-term use.
Cultural Perceptions of Asian Eyes
There are mixed global perceptions on the distinctive eyes of Asians:
Positive Associations
- Alluring, feminine beauty
- Sign of youth – babies often have monolids
- Trendy, cool aesthetic (e.g. fox eyes)
- Project wisdom, intellect and emotional depth
- Unique and exotic look
Negative Stereotypes
- Indicator of foreignness and racial “otherness”
- Perceived as less expressive and friendly
- Monolids described as “slant eyes” or “squints”
- Deemed less desirable, plain and sleepy-looking
- Mocked for reduced vision abilities
- Used in caricatures and racist depictions
Being the subject of both exoticized fetishism and xenophobic discrimination, the eyes of Asians have carried complex cultural symbolism and meanings throughout history.
Why Monolid Representation Matters
Many Asians are taking to social media to celebrate and destigmatize the natural monolid eyes they previously felt pressured to hide. Positive representation is critical, especially for young girls.
Reasons monolid pride and visibility are so important:
- Combats internalized racism and promotes self-acceptance
- Provides diverse beauty role models
- Challenges Eurocentric beauty ideals
- Promotes ethnic identity and confidence
- Overcomes stigma and mocking
- Reduces harmful desire for ethnoplasty
- Resists pressures to conform to Western standards
Seeing monolids portrayed as normal and beautiful helps counter the pervasive message that creased, double lids are superior. Monolid visibility empowers young Asians to cherish their natural features.
Conclusion
In summary, epicanthic folds and monoids arose in ancient East Asian populations as evolutionary adaptations to harsh Siberian climates. They subsequently became engrained as common phenotypes due to genetic mutations. Though strongly associated with Asians, similar eye shapes occur sporadically in groups worldwide that evolved in frigid environments. The power of mirror gazing reveals the complex interplay of societal beauty constructs and ethnic identity, as the controversial pursuit of double eyelids through surgery and temporary methods exposes the diverse preferences and cultural pride. After millennia of evolution, these unique windows into the soul connect us to the resilience of our ancestors.
Frequently Asked Questions
Q: Are all Asian eyes the same?
A: No, there is significant diversity. Epicanthic folds, monolids, and double lids occur in varying proportions across East Asia, Southeast Asia and Asia overall. There are also differences between individuals and ethnic subgroups.
Q: Do eyelid folds negatively impact vision?
A: There is little evidence that epicanthic folds themselves impair sight. In rare cases they may obstruct side vision. But folds can sometimes occur in syndromes that affect vision like Down syndrome.
Q: Does every Asian person have monoid’s?
A: No. Many Asians naturally have double eyelids while some develop creases with age. But monoids do commonly occur in over 90% of East Asians and Southeast Asians. Other groups like South Asians have lower rates.
Q: Can taping methods permanently create double eyelids?
A: Tapes and glues temporarily modify the eyelid by adhesive traction. They cannot permanently alter the underlying structure or create lasting creases. Only cosmetic blepharoplasty surgery reshapes the eyelid.
Q: Do epicanthic folds offer protection like “snow goggles”?
A: Somewhat. The folds and monoids do filter sunlight and glare reflected off snow and water which likely helped Ice Age hunter-gatherers traversing the tundra. But they are not as visually protective as slitted snow goggles.
