Therefore, this finding adds further evidence to the idea that alcoholism has a genetic component.Ī study published in American Journal of Medical Genetics, Part B: Neuropsychiatric Genetics found that European Americans with blue eyes had up to 83 percent higher odds of becoming dependent on alcohol, compared with matched controls who had darker eye colours. People With Blue Eyes May Have a Higher Risk of AlcoholismĪ new study suggests that individuals with blue eyes are at a higher risk for alcohol dependency compared to those with darker eyes. However, since human melanin tends to develop over time - this causes the child's eye colour to change as more melanin is produced in the iris during early childhood.Ħ.
BLACK PEOPLE WITH BLUE EYES FULL
Since the human eye does not have its full adult amount of pigment at birth, most Caucasian babies are born with blue eyes. While blue eyes may be rare, they’re among the most common eye colours at birth. Blue Eyes at Birth Doesn’t Mean Blue Eyes For Life They have all inherited the same switch at exactly the same spot in their DNA.”ĥ. The “switch”, does not, however, turn off the gene entirely, but rather limits its action to reducing the production of melanin in the iris – effectively “diluting” brown eyes to blue.Īccording to Hans Eiberg, associate professor in the Department of Cellular and Molecular Medicine from the University of Copenhagen, “From this, we can conclude that all blue-eyed individuals are linked to the same ancestor.
BLACK PEOPLE WITH BLUE EYES SKIN
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).
Therefore, we can conclude that this genetic mutation is the cause of eye colour of all blue-eyed humans alive on the planet today.Ī genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a “switch”, which “turned off” the ability to produce brown eyes. 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 6,000 to 10,000 years ago led to the development of blue eyes. All Blue-Eyed People May Have A Common Ancestor 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.Ĥ. For these reasons, having less melanin in your irises means that you need to protect your eyes more from the sun’s UV rays. Since blue eyes contain less melanin than green, hazel or brown eyes, photophobia is more prevalent in blue eyes compared to darker coloured eyes. Melanin in the iris of the eye appears to help protect the back of the eye from damage caused by UV radiation and high-energy visible “blue” light from sunlight and artificial sources of these rays. More blue light gets back out and the eyes appear to be blue. 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. For people with brown eyes, some of the cells also have brown pigment in them. The front layer of the iris (called the stroma) is made up of overlapping fibers and cells. For almost everyone - even people with blue eyes - the back layer (called the pigment epithelium) has brown pigment in it.
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 colour of our eyes depends on how much melanin is present in the iris. 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.Ģ. If you have got blue eyes, you might just belong to one of the world’s most exclusive groups without realising it! Since blue eyes are genetically recessive, only 8 percent of the world's population has blue eyes. Only 8 Percent of the World's Population Has Blue Eyes
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