African-Americans with blue eyes are not unheard of, but they are pretty rare. To understand how this uncommon occurrence can happen, you must first look at the origins of blue eyes, which scientists say is a fairly newer phenomenon.
Distribution of eye color in the world
The Origins of Blue Eyes
“Originally, we all had brown eyes,” Professor Hans Eiberg from the university’s Department of Cellular and Molecular Medicine, argues in the study. Blue eyes actually originally came about because of mutations! Thousands of years ago, someone had a random change in the genes that affect eye color.
The OCA2 gene formerly called the P gene is a gene code that produces a pigment called melanin, according to scientists with Medline Plus. Scientists believe the mutation altered the amount of melanin produced in the iris of the eyes. Europe was the epicenter of the blue-eye gene mutation. Europe has the widest variety of eye color, according to Custers, who adds those of European descent are the largest population of blue eyes. Custers’ research suggests that Black people with blue eyes are affected by the same OCA2 genetic mutation in the same way any other human is, despite the mutation originating in Europe.
Mutations in DNA can happen. Remember, our bodies have “proofreading” repair machinery that fix these mutations. So even if a mutation occurs, these enzymes swoop in and try to correct them! But occasionally, some mutations get missed and eventually inherited. Scientists have studied how good these repair enzymes are, and how often they make mistakes.
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Blue is the second most common eye color globally, with an estimated 8 to 10 % of people having blue eyes. A majority of these people are of European descent, however, Black people can be born with blue eyes even though it’s pretty rare.
Eye color distribution
Genetic Reasons for Blue Eyes in People of African Descent
There are a number of genetic reasons why a person of African descent might have blue eyes. It is possible that there are white relatives on both your mother's and your father's side of the family. You need to have Caucasian relatives on both sides of your family, for reasons that I will explain here.
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Remember that for most genes, you have two copies of each gene, one inherited from your mother and the other from your father. Each gene can come in slightly different versions, called alleles. For most pigmentation genes, the allele for darker colors is stronger, or dominant. The allele for lighter colors (like blue eyes!) is weaker, or recessive. So someone with one brown allele and one blue allele would have brown eyes. Even though they have the DNA for blue, it’s hidden.
The reason it can take a few generations to see something like blue eyes is that it is partly caused by a recessive gene. To help understand how this works, let's give an example. The brown version of the eye color gene (B) is dominant over the recessive blue version (b). Dominant means that if either of your genes is the B version, then you will have brown eyes -- blue is recessive to brown.
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How could two brown-eyed people have a blue-eyed baby? The most likely way is if both were carriers for blue eyes (Bb). Each parent could contribute a b version of the gene so that the child would be bb and have blue eyes. One of the ways blue eyes can stay "hidden" for a long time is if there are always marriages between Bb (brown eyed carriers of blue eyes) and BB folks.
The genetics involved are actually even more complicated, making it even harder to get blue eyes. There are at least two, and probably more, genes that contribute to eye color. All of your copies have to be the blue kind to get blue eyes.
Genetics of eye color
Another possibility is that a key eye color gene was mutated or changed in you so that you now have blue eyes. These sorts of mutations are very rare, but it is where all the wonderful variety of people you see around you originally came from.
A recessive gene can hide in a family, and take a few generations to reappear. The most likely genetic explanation for your friend is that her father is a carrier for blue eyes and blonde hair.
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Case Study: Multiracial Babies with Unexpected Traits
Smith's mind was blown by genetics in her multiracial babies."My son's father is half Black and half white, I'm full Black, so my son is a quarter white and three quarters Black," the 26-year-old told Newsweek. "My daughter's father is Puerto Rican, so she's half Puerto Rican and Black."
She and her husband Charles Robert Simmons, 28, were expecting more brown features, since Black is the most dominant race in both cases. Both Smith's parents are Black, with brown hair and brown eyes-traits she inherited as well. Simmons, though adopted, knows his biological father is also Black with brown hair and brown eyes. His mother, however, is white with blonde hair and blue eyes-a genetic detail that turned out to play a key role in their children's appearance.
When their son, was born with blonde hair and blue eyes, "we were honestly stunned," Smith said. "The whole pregnancy we were just picturing a more brown baby considering Black is our most dominant race between us," she continued. "So when he came out blonde hair, blue eyes we had to ask ourselves who he inherited his features from. Sure enough it was grandma!"
Multiracial family
Smith's clip went viral within a few days of posting. Pinned to her profile, the 20-second clip has been viewed over 312,000 times. Dozens of users commented, many of whom shared their own stories of how genetics have played out in their children.
"Mine are opposite! One-quarter Black, three-quarters white. They're all 4 different, but you can tell they're all siblings," one user wrote. "My daughter is half Black, one-quarter Mexican, one-quarter white. She has natural blonde 4a hair," another shared. "My kids are one-quarter Black and three-quarters white and they both didn't get my blue eyes. But my daughter did get light brown straight hair and their dad and I both have dark curly hair.
Ruling Out Other Possibilities
Albinism comes about when your body fails to make melanin, the pigment that gives skin, hair, and eyes their dark color. Albinism can be ruled out if your friend is not light-skinned. Since poor vision is part of the diagnosis for albinism, if your friend does not have poor vision, they are not albino. A person with albinism.
There are a number of reasons why you probably don't have OA. People with OA tend to have very poor eyesight, something you didn't mention in your description. The final reason is that you are a woman. Similarly to OA, it’s unlikely that you have Waardenburg Syndrome.
Albinism
The Broader Context of Genetic Diversity
Africa represents the cradle of human genetic diversity. The presence of blue eyes in Black Africans represents a beautiful example of human genetic diversity and our shared ancestry. Understanding genetic diversity helps build more inclusive, educated communities.
In 2020, a heartbreaking story emerged from Nigeria that highlights deep-seated misconceptions about genetic diversity in African populations. A woman and her children faced rejection and accusations of witchcraft from their own family-simply because they possessed striking blue eyes.
The majority of Africans possess beautiful brown eyes, ranging from deep chocolate to warm amber tones. These eyes contain higher levels of melanin, creating rich, captivating patterns that vary uniquely from person to person. Many Africans also have dark, caramel-coloured eyes that create a stunning contrast between their dark irises and bright whites.
Approximately 2% of the world’s population has green eyes, and while rare, some individuals of African descent possess this striking eye color. Blue eyes represent the rarest eye color variation among African populations, occurring in only 6-8% of the global population. Eye color is determined by the amount and distribution of melanin in the iris-the colored part of the eye.
Groundbreaking research from the University of Copenhagen revealed that all individuals with blue eyes share a common genetic ancestor. Blue eyes can appear in children when both parents carry the recessive gene, even if neither parent has blue eyes themselves.
For many people, learning their ancestry may come as a shock. Traits like blonde hair and blue eyes occur most often in European countries - especially Northern Europe. Traits like straight black hair occur most often in Indigenous American and East Asian people. Some traits are inextricably tied to your ancestry. Learning information that calls into question your identity can feel overwhelming and disorienting.
