Eye color exhibits a wide spectrum of hues across the global population. Among these, amber eyes stand out as a distinct and less understood eye color.
Defining Amber Eyes
Amber eyes possess a solid, uniform coloration. They typically display a golden, coppery, or yellowish hue, resembling amber or honey. This appearance lacks flecks, rings, or variations, presenting a consistent tone throughout the iris.
Amber eyes differ from hazel eyes, which contain multiple colors like green, brown, and gold, and shift with lighting. Amber eyes maintain a consistent golden or coppery color and do not exhibit color-shifting. They also differ from light brown eyes, which may darken indoors, whereas amber eyes retain their yellowish-gold tint regardless of lighting.
Global Rarity and Distribution
Amber eyes are considered rare globally. Estimates suggest only about 5% of the world’s population possesses true amber eyes, making them one of the less common eye colors alongside gray and green.
While uncommon overall, amber eyes are observed with higher frequency in certain geographical regions and among specific populations. They are more commonly found in individuals with Asian, South American, Spanish, and Southern European ancestry. Countries and regions like Pakistan, Italy, Hungary, southern France, the Middle East, and South Africa also show a higher incidence. Their presence is often linked to mixed genetic backgrounds and historical migration patterns.
The Science Behind the Hue
The amber color results from the specific types and concentrations of pigments within the iris. The two main pigments influencing eye color are melanin (eumelanin (brownish-black) and pheomelanin (reddish-yellow)) and lipochrome. In amber eyes, there is a relatively high concentration of pheomelanin (also known as lipochrome) combined with a lower concentration of eumelanin. This balance creates the golden or coppery hue.
The specific combination and distribution of these pigments in the iris stroma produces the uniform amber coloration. While melanin is the dominant pigment in most eye colors, lipochrome plays a more prominent role in creating the yellow and golden tones. Eye color inheritance is a complex trait influenced by multiple genes, with up to 16 different genes playing a role. Genes like OCA2 and HERC2 are particularly significant, regulating melanin production and distribution, and specific genetic variants lead to the less common combination of pigments that results in amber eyes.