YOUR AMAZING BODY

Blue and green eyes are in fact colourless

THE front of the coloured part of the eye, the iris, is made up of fibres of colourless proteins and pigment. The amounts of each determines eye colour.

Brown eyes have more melanin, giving them their dark colour. Blue eyes have no pigment at all. But when light hits their proteins, it ‘scatters’, as a result of something called the Tyndall effect, which makes them appear blue. It’s a similar effect to the one that makes the sky look blue. It means that blue eyes don’t have a set colour – it all depends on the amount of light available when you look at them.