Blinking Colours The Eye Of The Beholder

They say that beauty is in the eye of the beholder, but what do they say about the beauty of the eye, if, they in question, happen to be great scientific minds? In a basic sense, eye colour is determined by iris pigmentation, and how well the stroma of the iris is able to scatter light.

- Flash Parker

Human eyes can appear brown, blue, green or hazel, depending on how much melanin is concentrated in the iris, though this appearance is something of a natural magic trick: green and blue pigments do not occur naturally in the iris; this colouration occurs as a result of light scattering. Think of this scattering in the way that light alters our perception of colour when striking certain metals; the way a car may appear blue from one angle, purple from another, and even green, depending on the angle and intensity of the sun.

Other animal species, such as birds, have more iris pigmentation than humans and thus these species exhibit a greater range of eye colours. Exceptionally complex, eye colour has been linked to as many as 15 genes and while inheritance traits are traceable to a certain extent, human offspring can exhibit nearly any eye colour combination, regardless of parent pigment profiles. But for all the eye’s complexity and beauty, scientists still don’t fully understand why eyes exhibit such great variation in colour.