Hazel eyes blend green, brown, and gold tones. Their appearance shifts subtly with lighting, distinguishing them from single-hued eyes. This multi-tonal quality often includes a golden or amber ring around the pupil, a green or light brown outer ring, and light-catching flecks.
The Global Rarity of Hazel Eyes
Globally, hazel eyes are uncommon, accounting for approximately 5% of the world’s population. In the United States, their occurrence is higher, estimated at 15% to 18% of the population. This higher prevalence in the US is partly due to diverse ancestral backgrounds, particularly those with European and Middle Eastern heritage.
Hazel eye distribution varies geographically. They are more frequent in regions like the Middle East, North Africa, Brazil, and Spain. Parts of Europe, including the Netherlands, the United Kingdom, and northern Germany, also show higher concentrations. Conversely, hazel eyes are less common in populations from Asia and Africa.
The Science Behind Hazel Eye Color
The color of hazel eyes comes from the amount and type of melanin within the iris and how light interacts with it. Melanin is the primary determinant of eye color. Hazel eyes have a moderate concentration of melanin, falling between the low levels in blue eyes and high levels in dark brown eyes.
Two main types of melanin contribute to eye color: eumelanin (brown and black tones) and pheomelanin (amber, golden, or reddish hues). Hazel eyes exhibit a blend of both, with their ratio and distribution creating the multi-tonal appearance. This coloration also involves light scattering within the iris, similar to Rayleigh scattering. There are no actual green or blue pigments in the human iris; these colors are perceived due to light scattering and melanin absorption.
Hazel vs. Other Eye Colors: A Comparative Look
Brown eyes are the most widespread, present in 70% to 80% of the global population. Blue eyes are the second most common, found in about 8% to 10% of people. Green eyes are the rarest among recognized eye colors, occurring in only about 2% of individuals globally.
Hazel eyes, with approximately 5% global prevalence, are more common than green eyes but less common than brown and blue eyes. Other less common eye colors include amber (about 5% of the population, sometimes mistaken for hazel) and gray eyes (roughly 3% of people).