Grey eyes are a rare and striking eye color that only a small percentage of the global population possesses. They are defined as eyes that are a light grey or blueish-grey color and contain low to moderate amounts of melanin pigment. Grey eyes are often confused with blue eyes, but unlike blue eyes where the color is from the presence of melanin, grey eyes get their color from the collagen fibers in the stroma or outer layer of the iris.
While grey eyes can genetically occur in any individual of any ethnic background, they are most prevalent in people of Northern European descent. This is due to evolutionary adaption and sexual selection in geographic regions with lower light levels. The leading ethnic and racial groups with increased chances of inheriting grey eyes include:
Caucasians / Europeans
Grey eyes are most common in people of full or predominant European ancestry, particularly Northern Europeans. This includes ethnic groups such as:
– British / English
– Scandinavian / Nordic (Norwegian, Swedish, Finnish, Icelandic, Danish)
– Slavic (Polish, Russian, Ukrainian, Czech, Slovakian, Slovenian, Serbian, Croatian, Bosnian, Bulgarian, Belarusian, Macedonian, Montenegrin)
– Baltic (Lithuanian, Latvian, Estonian)
Studies show that in these Northern European populations, between 10-30% of people have blue, gray, or green eye colors. The lightest eye colors including grey eyes peaked in Scandinavia and the Baltic region where over 90% of people have light eyes.
In Eastern European ethnic groups, grey eyes are also relatively common at around 10-25% frequency. This includes people of:
The further south or east in Europe, generally the lower prevalence of light eye colors including grey eyes in the native populations.
Grey eyes also occur with higher than average frequency in the Ashkenazi Jewish population. Around 1 in 4 Ashkenazi Jews has blue, gray, or green eyes inherited from Northern and Eastern European ancestry.
In Latin American countries, grey eyes may be found in people with European heritage, particularly Spanish, Portuguese, French, Irish, and German roots. For example around 15-25% of people in Argentina and Uruguay have light eyes.
North Africans / Middle Easterners
Some ethnic groups in North Africa and the Middle East also have slightly elevated rates of light eye colors due to ancient Indo-European ancestry and admixture with European populations. This includes:
But percentages are still low at around 1-5% of these populations.
The Roma people or Romani population of Europe may also have a slightly increased rate of grey eyes, perhaps around 5-15%, due to some shared ancestral heritage with Eastern Europeans.
Central Asians / Turkic Groups
Some Central Asian and Turkic ethnic groups where grey eyes can be found due to ancient Indo-European admixture include:
But again percentages are quite low around 1-5% of these populations.
South Asians / Indians
In South Asian populations like India, grey eyes are very rare. However, they can be found in some ethnic groups in North India and Pakistan that have ancestral links to Indo-European, Central Asian, or Iranian populations. This includes Punjabis, Pashtuns, and Kashmiris. The percentage is around 1-5% at most in these groups.
Grey eyes essentially do not occur naturally among East Asian ethnic groups like Chinese, Japanese, Korean etc. These populations have almost 100% brown eye coloration.
In Southeast Asia, grey eyes are also extremely rare among ethnic groups like Filipino, Vietnamese, Thai, Indonesian, etc. Some lighter eye colors may be seen due to Spanish and American ancestry in the Philippines. But overall, Southeast Asians have almost entirely brown eyes.
There are virtually no individuals with true grey eyes among indigenous Native American populations. Essentially 100% of full-blooded Native Americans have brown eyes.
Similarly, native Pacific Islander ethnic groups like Hawaiiians, Samoans, Tongans, Fijians etc. have exclusively brown eye coloration with no prevalence of grey eyes.
Aboriginal Australians / Melanesians
Indigenous ethnic groups of Australia, Melanesia, and Papua New Guinea, uniformly have brown eye color only. Grey eyes are non-existent.
Among Sub-Saharan African populations, grey eyes are also completely absent. Eye colors are almost 100% dark brown among ethnic groups like Nigerian, Kenyan, Ethiopian, Congolese, Ghanaian, etc.
In summary, grey eyes have the highest prevalence in white populations of European origin, particularly Northern Europe and Eastern Europe. They also occur at low to moderate frequency in some populations of the Middle East and Central Asia that have Indo-European ancestry. Essentially the only major ethnic groups where grey eyes are completely absent are East Asians, Southeast Asians, Sub-Saharan Africans, Native Americans, Pacific Islanders, and Aboriginal peoples of Australia/Melanesia. So while grey eyes can genetically occur in any individual, they are uniquely a signature trait of Caucasian and some West Asian peoples.