The surprising science behind the colour of your eyes - and what it reveals about your personality

Daily Mail​

29-05-2025

A viral TikTok video has revealed the remarkable science and deep symbolism behind eye colour - suggesting your eye shade might say more about you than you think.
The clip, posted by user @snappybits2, explores how brown, blue and green eyes are shaped not only by biology but by history and light itself.
According to the video, brown eyes are caused by a high concentration of melanin - the pigment responsible for colouring the skin, hair and eyes.
In the iris, melanin acts as a shield that absorbs light rather than scattering it.
'Brown eyes pull light inward,' the narrator of the video explains. 'This is why brown eyes seem deeper, darker and more grounded.'
The earliest humans had brown eyes, having evolved near the equator where the sun was most intense.
'Melanin wasn't just pigment. It was protection. Brown eyes were nature's built-in sunglasses, filtering out UV rays and reducing glare long before Ray Bans existed.'
Today, over 70 per cent of the global population has brown eyes - a striking reminder of their evolutionary significance. The video describes the colour as 'not just a colour, but a legacy'.
Culturally, brown eyes are often associated with warmth and reliability, but they've also been viewed as 'mysterious, serious, even intimidating.'
This, it claims, is because 'brown eyes are hard to read. They don't change with the light.
'They don't flash with emotion the way lighter eyes sometimes do. They absorb rather than reveal.'
But under certain lighting - low sun, candlelight, late afternoon haze - something remarkable can happen.
'Brown eyes start to glow… amber, honey, liquid gold,' the narrator continues. 'It's the melanin, again, scattering light just enough to reveal what's been hiding underneath
'In those moments, they feel ancient, like they're not just seeing you, they're remembering you.
Unlike brown, blue eyes contain almost no melanin at all.
Instead, what we perceive as blue is actually an optical illusion created by light scattering through layers of transparent iris tissue, a phenomenon known as Rayleigh scattering.
'There's no blue pigment inside the iris,' the narrator explains. 'What you're seeing is the light scattering through layers of tissue.
'It's the same reason the sky looks blue and sunsets bleed orange.'
Every blue-eyed person on Earth, around 8 per cent of the population, shares a common ancestor.
'They trace their eye colour back to a single genetic mutation that occurred 6,000 to 10,000 years ago, somewhere near the Black Sea, in one human.'
The mutation, found in the OCA2 gene, limited melanin production in the iris.
'Suddenly the eye didn't absorb light anymore, it scattered,' the video says.
'That one mutation spread from person to person, generation to generation, until millions now carry the glitch.'
The result is eyes that aren't truly blue, but instead 'the colour of light's confusion.'
Green eyes are the rarest of all, seen in just 2 per cent of the global population, making them less common than red hair or even being born with 12 fingers.
They're described as a 'chemical contradiction, a perfect storm between biology and light'.
To achieve green eyes, the body must produce just the right balance of melanin and a yellowish pigment called lipochrome, along with the scattering effect of light.
'Most people have too much melanin and their eyes come out brown. Some people have almost none, and their eyes appear blue,' the narrator explains.
'But green eyes need just enough melanin to darken the iris and just enough lipochrome to tint the light that bounces off it.'
The video calls green eyes 'a rendered illusion so delicate that the smallest tweak in pigment breaks the effect entirely.'
And they don't stay the same. 'Green eyes don't sit still. They shift in different lights - gold, jade, moss, steel.
'They look calm in the shade, then snap with energy and sunlight, like they've got a secret loaded behind the iris waiting to be triggered.'
Green eyes, it says, are 'unstable beauty, an optical accident.'
Whether a product of melanin's shielding power, a 10,000-year-old genetic glitch, or a collision of pigment and light, your eye colour might be revealing more about you than you ever realised.