How old is the blue eyed gene

Both parents may have icy blue eyes, but that's no guarantee their child's eyes will even be blue at all. Human eyes don't have their full amount of melanin pigment at birth.

This is why many babies are born with blue eyes, only to have their eye color change as their irises develop more melanin throughout early childhood. So don't be concerned if your child begins to lose their baby-blue eye color. It's completely normal to see blue become brown, hazel, or even green as they get a little older. Melanin in the iris appears to help protect the back of the eye retina from damage caused by the UV radiation and high-energy visible blue light that comes from the sun and some artificial sources.

Because blue eyes contain less melanin than most other eye colors, they may be more at risk of certain damage. Research has shown that lighter iris colors are associated with:. A higher risk of ocular uveal melanoma a type of eye cancer. No difference in the risk of developing age-related macular degeneration. Since many people with blue eye color are more sensitive to light and may have a higher risk of retinal damage from UV rays, eye doctors often recommend that people with blue eyes be a little more cautious about their exposure to sunlight.

Photochromic lenses are another way to protect blue eyes from UV radiation. Blue-eyed humans have a single, common ancestor. One theory is that the gene could have helped to prevent eye disorders due to low light levels found in European winters, or that the trait spread because it was deemed sexually attractive. Join thought-provoking conversations, follow other Independent readers and see their replies.

Want to bookmark your favourite articles and stories to read or reference later? Start your Independent Premium subscription today. More about Biology Eyes Genetics Teeth. While blue eyes are significantly less common than brown eyes worldwide, they are frequently found from nationalities located near the Baltic Sea in northern Europe. The colour of our eyes depends on how much melanin is present in the iris. Blue eyes get their colour the same way water and the sky get their blue colour — they scatter light so that more blue light reflects back out.

The iris is made up of two layers. For almost everyone — even people with blue eyes — the back layer called the pigment epithelium has brown pigment in it. The front layer of the iris called the stroma is made up of overlapping fibers and cells. For people with brown eyes, some of the cells also have brown pigment in them. If there is no pigment at all in this front layer, the fibers scatter and absorb some of the longer wavelengths of light that come in. More blue light gets back out and the eyes appear to be blue.

Blue Eyes are More Sensitive to Light. Since blue eyes contain less melanin than green, hazel or brown eyes, photophobia is more prevalent in blue eyes compared to darker coloured eyes. Therefore, it is recommended to those with blue eyes to stay out of the sun for long periods of time and try to wear protective eyewear when you are outdoors.

Originally we all had brown eyes, however, according to researchers at the University of Copenhagen, it appears that a genetic mutation in a single individual in Europe 6, to 10, years ago led to the development of blue eyes. Therefore, we can conclude that this genetic mutation is the cause of eye colour of all blue-eyed humans alive on the planet today.

What is the genetic mutation? The OCA2 gene codes for the 'P protein', which is involved in the production of melanin the pigment that determines the colour of our eyes, skin and hair.