All blue-eyed people have one thing in common – aside from having blue eyes.

It’s the second most popular eye colour in the world and the shade is believed to have originated around 6,000 to 10,000 years ago.

The widespread iris coloration apparently started due to a genetic mutation as, originally, all humans had brown eyes – in different shades.

There are plenty of other interesting things about blue-eyed people too.

For example, they are more sensitive to light – if you have more melanin in the iris, it means you have more protection in the back of the eye from UV radiation and blue light damage, as per Auckland Eye.

So as people with blue eyes have less melanin than other colors, photophobia (abnormal sensitivity to light) is usually more common.

While this may sound negative, there are many positives to having blue eyes.

A study by Louisville University professor Joanna Rowe found that people with this eye shade are more likely to be better strategic thinkers, as reported by the Daily Mail.

The professor clarifies: “It is just observed rather than explained. There’s no scientific answer yet.”