by Aimee Walker
August 7, 2023, 2:42 pm
Updated: February 27, 2024, 10:34 am
Credit: Alamy
Around eight to ten per cent of the population have blue eyes and apparently, they all have one thing in common.
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 colouration is believed to have started due to a genetic mutation as, originally, all humans had brown eyes – in different shades.
There are many interesting things about blue-eyed people.
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 colours, photophobia (which means abnormal sensitivity to light) is usually more common.
While this may sound like a negative, there are actually many perks to having blue eyes.
All blue-eyed people have one thing in common. Credit: Alamy
A study, conducted by Louisville University professor Joanna Rowe, has found that people with this eye shade are more likely to be better strategic thinkers, as reported by Daily Mail.
The professor clarifies: “It is just observed rather than explained. There’s no scientific answer yet.”
There are many celebrities with blue eyes who have bright minds, including Stephen Hawking, Alexander Fleming and Marie Curie.
But most interestingly, all blue-eyed people have one thing in common…
Recently, a gene has been identified that causes blue eyes, and it’s called HERC2.
This gene switches off OCA2 – which results in different shades of brown eyes – and it determines the amount of brown pigment melanin that we make.
Professor Hans Eiberg, from the University of Copenhagen’s Department of Cellular and Molecular Medicine, explains: “Originally, we all had brown eyes. But a genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a ‘switch’, which literally ‘turned off’ the ability to produce brown eyes.”
The majority of the population has brown eyes. Credit: Alamy
It is believed to have originally begun when humans first migrated from Africa to Europe, The Independent details.
The University of Copenhagen study suggests that all blue-eyed people are descendants of one person.
Although it remains a mystery who first started this initial mutant gene, the fact every blue-eyed person has this mutation is pretty compelling evidence.
Professor Eiberg says in the report that the research into the genetic mutation of people with blue eyes ‘simply shows that nature is constantly shuffling the human genome, creating a genetic cocktail of human chromosomes and trying out different changes as it does so’.
Written by Aimee Walker
Aimee is a senior content editor at IGV who specialises in finding the best original stories, trending topics and entertainment news. She graduated from Birmingham City University with a degree in Media and Communications.
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