Brown eyes

How common are brown eyes?

Brown is the most common eye color in the world, at an estimated 70–80% of people. That range comes from secondary summaries such as WorldAtlas and All About Vision. Nobody has counted eye color worldwide, so we treat it as an estimate. Even so, we give brown our only high-confidence label, because no serious source disputes the order of magnitude.

The United States is where we have real counts, and two datasets disagree. A 2025 PLOS ONE study of 235 million driver's licenses found brown or black eyes on 53% of them. A 2014 Harris Poll of more than 2,000 Americans, run for the American Academy of Ophthalmology, found 45%.

We lean toward the license figure because the sample is far larger. It still has gaps. Only 31 states supplied data, the records date from 2016, and people pick their own eye color at the DMV counter. The share also swings widely by state, from 34.3% in Wyoming to 67.1% in Texas.

What makes eyes brown?

Brown eyes are brown because the front layer of the iris holds high levels of melanin. Melanin absorbs most of the light that reaches it, so very little bounces back out. The same pigment colors skin and hair.

Melanin comes in two forms. Eumelanin is brown-black and pheomelanin is red-yellow. Research on iris tissue found that the ratio shifts with color: about 14.8 to 1 in dark brown irises, against about 1.3 to 1 in blue-green and hazel ones. So a dark brown iris has both more pigment and a darker mix of it.

The genes that set this level are covered in our genetics guide. The short version is that OCA2 and HERC2 on chromosome 15 do most of the work, and dozens of other regions adjust the result.

Where are brown eyes most and least common?

Brown dominates almost everywhere outside northern Europe. The best country-level figures come from a 2019 literature review by Katsara and Nothnagel, in the table reproduced by Healthline.

Two warnings come with this table. The review counted hazel as brown, so true brown is lower in each row. Its data is also mostly European, because few comparable surveys exist for Africa and Asia. Brown is close to universal in those regions, but we can't give you a measured percentage for them.

Are black eyes real?

No. Eyes that look black are very dark brown. The iris absorbs so much light that it blends into the pupil, especially indoors. Under a bright light the brown shows.

This is why U.S. license forms use a combined "brown/black" category. It reflects how people describe their eyes, not a separate color.

Are babies born with brown eyes?

Most are, at least in the one hospital study we have. The old claim that all babies start with blue eyes doesn't hold up. In the Newborn Eye Screening Test study, 63% of 192 newborns had brown eyes and 20.8% had blue. That is a single hospital in California, so it won't match every population.

Eyes can also keep changing later than most people assume. Our guide to blue-eyed parents and brown-eyed children covers how a baby's color settles.

Does having brown eyes affect eye health?

A little, in both directions, and only as a statistical link. A 2014 review of epidemiologic studies reported that darker irises were linked to more age-related cataract and to a lower risk of uveal melanoma. It found no consistent link with age-related macular degeneration.

None of this tells you anything about your own eyes. Regular eye exams matter far more than your iris color.