In light of that, have you ever wondered why some people green eyes, while others have brown ones?
One study claims that the dominant eye colour in Britain, with 48 per cent, is blue.
But why the difference?
The iris is the part of your eye which determines pigmentation.
The colour itself is made up of three genes, which is partially why there is such a wide variety of eye colours. Two of the genes are found on chromosome 15 and a third is on chromosome 19.
Two of them account for the most common of eye colours: brown, blue and green.
The third, which contributes to the development of grey and hazel eyes, is less understood.
Just because parents have brown (or blue) eyes doesn’t guarantee that their children will have the same coloured eyes. Most babies are born with blue eyes, which darken within three years.
Brown is a dominant gene, which means if your mum and dad both had brown eyes, you’ll probably have brown eyes too. But it’s not a rule, and you may well have different coloured eyes from your parents.
Research has found that blue eyes have a single common ancestor, tracking it back to between 6,000 to 10,000 years ago, making it a new colour.