Brown is the most common eye color in the United States, belonging to about 53% of the population. That’s roughly 125 million Americans. Blue comes in a distant second at 23.7%, followed by hazel at 10.3% and green at 9%. Grey is the rarest common category, showing up in less than 1% of the population.
Full Breakdown by Color
A large-scale analysis published in PLOS One examined driver’s license records across the country to map out eye color distribution. The results paint a clear picture of where Americans fall:
- Brown/black: 53%
- Blue: 23.7%
- Hazel: 10.3%
- Green: 9%
- Grey: 0.7%
- Other: 3.3%
Brown’s dominance isn’t surprising. It’s the most common eye color globally, and the U.S. population reflects a broad mix of ancestries where brown eyes are the norm. What may surprise people is just how uncommon green and grey eyes are. Combined, they account for less than 10% of all Americans.
Why Brown Eyes Are So Common
Eye color comes down to melanin, the same pigment that determines skin and hair color. Brown eyes contain the most melanin in the iris. Blue eyes contain very little. Green and hazel fall somewhere in between. There is no blue or green pigment in the eye. Lighter colors are the result of how light scatters through an iris with less melanin, similar to how the sky appears blue even though the atmosphere isn’t colored.
Two genes on chromosome 15 do most of the heavy lifting. One, called OCA2, produces a protein involved in creating and storing melanin inside the iris. The other, HERC2, acts like a control switch that turns OCA2 on or off. Common variations in either gene can reduce melanin production, which is what leads to lighter eye colors. At least eight other genes play smaller roles, which is why eye color doesn’t follow simple dominant-recessive inheritance the way many people learned in school. Two brown-eyed parents can have a blue-eyed child, and the range of possible shades is far wider than a basic genetics chart suggests.
What Makes Hazel Eyes Different
Hazel is one of the trickier categories because it’s not a single uniform color. Hazel eyes contain more melanin than blue or green eyes but less than brown. They appear as a combination of brown, gold, and green, though the exact mix varies from person to person. Some hazel eyes look mostly green with a ring of brown near the pupil. Others lean heavily gold or amber. The color can even appear to shift depending on lighting or what someone is wearing, which is why hazel-eyed people sometimes get different answers when others try to label their eye color.
Blue Eyes Have Been Declining for Decades
A century ago, more than half of Americans had blue eyes. Today that number sits below 24%. The shift reflects changes in immigration patterns and the demographics of the U.S. population over the 20th century. As the country became more ethnically diverse, the proportion of people carrying the gene variants associated with lighter eye colors naturally decreased. Brown-eyed genes tend to be more dominant in inheritance, so in a population where people of varied ancestries are having children together, brown eyes become more likely with each generation.
This doesn’t mean blue eyes are disappearing. The gene variants responsible for them still exist in a large portion of the population and will continue to be passed down. But as a share of the total population, blue eyes are unlikely to return to the levels seen in the early 1900s.
Eye Color and Health
Eye color isn’t purely cosmetic. The amount of melanin in your iris affects how much UV light it absorbs, which has real consequences for certain eye conditions. Age-related macular degeneration, the leading cause of vision loss in older adults, is more common in people with blue eyes. The lower melanin levels in lighter irises offer less natural protection against light damage over a lifetime.
People with lighter eyes also tend to be more sensitive to bright light, a phenomenon called photophobia. If you have blue or green eyes and find yourself squinting more than others on sunny days, that’s a direct result of having less pigment to block incoming light. Wearing UV-blocking sunglasses matters for everyone, but it’s especially worth the habit if your eyes are on the lighter end of the spectrum.