
Research shows that every blue-eyed person on Earth shares a unique connection stemming from a single genetic mutation that affects a specific gene in our chromosomes.
Did you know that blue is the second most common eye colour globally, behind brown?
A whopping eight to ten percent of the world’s population have azure peepers, with some being quick to tell you they’re actually ice-blue or maybe even turquoise, thank you very much.
Despite the iris colour being pretty common, it may excite you to learn that people with blue eyes are connected to every other person they come across with cobalt-coloured eyes. Fun, right?
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Our eye colour is determined by the OCA2 gene, which provides instructions for making the P protein. This protein is involved in pigmentation and is believed to play a key role in melanin production.
However, researchers from the University of Copenhagen found that people with blue eyes have a totally different gene present.
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This one is called HERC2 and is essentially responsible for switching off OCA2.
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Further research indicated that all people with blue eyes shared this gene with one common ancestor.
It’s understood that the mutation began when humans first migrated to Europe from Africa, explaining why blue eyes are typically present in those with European descent.
Professor Hans Eiberg, part of the university’s Department of Cellular and Molecular Medicine, explained: “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.”
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This supposed first ancestor who exhibited the genetic mutation is thought they lived more than 6,000 to 10,000 years ago, passed down through generations in the genetic pool.

Professor Eiberg said the presence of the HERC2 gene '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'.
"They have all inherited the same switch at exactly the same spot in their DNA."
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The expert added that people with green eyes (which only around two percent of the population has) have a 'reduced amount of melanin in the iris, which is very different to those with blue eyes'.
While we blue-eyed people may not be able to claim our eye colour is as rare as our green counterparts, we can take comfort in the fact that men with sapphire irises are highly rated on dating apps.
According to a 2021 study by Lenstore, blue eyes were more desirable in male partners, while the hazel-eyed girlies were luckier in love, apparently.