Genetics are a big part of it, like you would expect, but its a bit more nuanced than what we learned in high school biology.

Studies have suggested that the contrast between the white of human eyes - known as the sclerae - and the colourful irises allows others to detect the direction of our gaze. The ability to detect gaze ...

The human eye functions like an exceptionally precise, high-end camera, one with a resolution of around 576 megapixels. What ...

Have you ever wondered why some people have lighter eyes than others? Differences in iris coloration have traditionally been explained as a result of sexual selection, but a recent study led by ...