Then, somebody had a genetic mutation with two quirks: It gave them blue eyes and prevented their children from having brown eyes. Genetic research suggests that until about 10,000 years ago, pretty much everyone had brown eyes. Eye color: The role of genetics and environment And some people’s eyes have different shades in different parts of the iris. Similarly, people with hazel, gray and green eyes have varying quantities of tint in the front layer. (This same effect makes the sky appear blue.) Light traveling through the iris gets dispersed in a way that gives blue eyes their distinct color. On top of that, blue eyes are not truly blue. Most people have brown tint in the back layer, but lighter eyes have less tint in the front layer.īlue eyes have almost no tint in the front layer of the iris. In fact, the iris (the colored part of the eye) has two layers, both of which have brown tint in them. That’s because eye color comes from melanin, the same brown pigment that gives color to our hair and skin. Why do eyes come in so many colors?Īlmost all humans have some brown in their eyes. Indeed, one study found evidence of blue-eyed hunters and gatherers roaming Spain 7,000 years ago. Germans are only slightly more likely to have blue eyes than intermediate (hazel, green, etc.) or brown eyes.īlue eyes have been common across Europe since prehistoric times. Iceland, the northernmost country of the bunch, has the greatest percentage of people with blue eyes.įrance, the southernmost nation on the list, has the largest number of people with “intermediate” (neither brown nor blue) eye color. Keep that 70-79% global estimate for brown eyes in mind when you look at the numbers below from a study in the journal “Forensic Science International: Genetics.” Nation How much lighter are the eyes of Northern Europeans compared to everybody else’s? Quite a bit. Brown eyes in an otherwise mostly light-eyed region may point to a genetic leftover and a time in history during which everyone in the world had brown eyes. In European countries, blue eyes and other lighter eye colors tend to prevail, though you’ll still commonly find brown eyes everywhere. It’s the dominant eye color in people with Native American and African ancestry, as well as those with family trees that trace back to Asia, the Middle East, Central or South America and other nations where brown eye color is the most common. That the majority of Americans have light eyes is likely a reflection of the country’s earliest immigration patterns, with many new inhabitants coming from European countries where blue eyes dominate.Īt the same time, nearly half of the U.S. A poll conducted for the American Academy of Ophthalmology resulted in the following percentages: The stats for the United States shake out a bit differently. The website takes a stab at estimating the breakdown of eye colors worldwide. For example, Asians typically have brown eyes, while Europeans are more likely to have eyes of blue or other lighter hues. The most common eye colors depend largely on geographic location. Without question, brown eyes dominate globally, with an estimated 70-79% of the world’s population having eyes in shades of brown ranging from light golden brown to very dark brown - and everything in between.īlue eyes are a distant second, followed by hazel eyes, green eyes, then “other.” This last category includes amber eyes, gray eyes and even violet eyes. Most common eye color? The browns have it. Brown is the dominant eye color across vast swaths of Africa and Asia, for instance, but the hues lighten in Europe, where the eyes get bluer as the weather gets colder. The answer largely depends on where you live or where your ancestors came from. Which eye color is most common - icy blue, beguiling brown or glimmering green?
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