silmavärvi

Silmavärvi is an Estonian term that translates to "eye color." It refers to the pigmentation of the iris, the colored part of the eye that surrounds the pupil. The color of a person's eyes is determined by the amount and type of melanin pigment present in the iris's anterior layers.

The most common eye colors are brown, blue, and green. Brown eyes are the most prevalent globally, due to a high concentration of melanin. Blue eyes have very little melanin, and the blue color is a result of light scattering in the stroma, similar to why the sky appears blue. Green eyes are less common and result from a moderate amount of melanin combined with light scattering. Other eye colors, such as hazel, amber, and gray, are variations of these basic colors, often involving a mix of melanin levels and light scattering properties.

Genetics plays a significant role in determining eye color. Multiple genes are involved, but the OCA2 and HERC2 genes are considered the most influential. While simpler models once suggested a straightforward dominant/recessive inheritance pattern, the reality is more complex, with contributions from several genes leading to a wide spectrum of possible eye colors. Eye color can also change over time, particularly in infants, as melanin production develops. In rare cases, medical conditions or injuries can also affect iris pigmentation.