Do you have blue eyes? Well then we’ve got some bad news, you see they’re not actually blue, they’re brown.
In fact everyone has brown eyes and it’s all thanks to something called melanin.
As you may or may not know, melanin is the pigment that determines our skin, hair and eye colour.
In relation to our eyes, Dr. Gary Heiting has a superb explanation on eye colour as part of a series by CNN.
In the piece Dr Heiting explains that the more melanin we have, the darker our eye colour, the less we have the lighter.
So why aren’t all our eyes just different shades of brown then? Well it’s to do with the light that’s then absorbed by the eye.
If you have lots of melanin cells (melanocytes) then the light gets absorbed and as such the darker brown comes through. If you have less, then more light is able to bounce back out of the eye in a process known as ‘scattering’.
As the light is reflected back at a very short wavelength, the corresponding colour this produces is, you guessed it, blue, thus countering any brown that was being caused by the melanocytes.
For those of you who claim to have eyes that change colour, congratulations, they actually do. This is because the amount of melanocytes you have is somewhere in the middle, resulting in changing amounts of light entering the eye.
It also helps to explain why almost all babies are born with blue eyes to begin with. As they grow and develop, the melanocytes start to build up and will eventually determine the eye colour that the baby will have for the rest of their life.
Heiting also gives us some background on where blue eyes may have developed.
It’s widely known that people who have high levels of melanin in their eyes, skin and hair have developed this genetic trait as a natural form of protection against their local climate e.g. Africa.
As humans travelled further north to cooler climates where the sun’s UV radiation is lower, it’s thought that we naturally evolved to use less of the pigment and as a result, blue eyes were born.
The genes that decide your eye colour can also influence other parts of you, with the most bizarre being your pain threshold.
Back in 2014 scientists from the University of Pittsburgh actually discovered a direct link between our eye colour and our ability to withstand pain.
Scientists’ findings suggest Caucasian women with light-coloured blue or green eyes can tolerate pain and better than those with darker brown or hazel eyes.