What is the significance of blue eyes

But you can always tell the difference between a natural blue and an artificial blue — it's a pretty hard color to fake. Although the odds of having blue eyes are markedly lower than having brown eyes, blue isn't the rarest of all eye colors.

In fact, it's actually the second most common eye color out there, according to an article in World Atlas , which is a little surprising given that 8 to 10 percent isn't exactly a huge swath of the population.

But it turns out that having hazel eyes is less common than having either blue or brown eyes, as only 5 percent of people have that color in their irises. Additionally, approximately 5 percent of the world's population have amber-colored eyes, although sometimes this is confused with the hazel pattern. Less common than either of those shades is green, as only 2 percent of the world's population is blessed with that phenotype. They're the real unicorns here!

Blue eyes can appear to be more or less common depending where in the world you are, as the phenotype is much more common in some places. In fact, sometimes the majority of people in an area have blue eyes. For example, if you were strolling through Estonia or taking a vacation in Finland, not having blue eyes would be rare, as 89 percent of the populations of those countries have azure irises, according to World Atlas. That's a lot! After that, there's a significant drop, although blue eyes are still the majority in Ireland and Scotland, at 57 percent and 50 percent, respectively.

England is next on the list with 48 percent, while 45 percent of people in Wales have baby blues. Belgium and France clock in at seventh and eighth on the list, with Finally, at places nine and ten are the United States and Spain, both with just over 16 percent of the population possessing cerulean eyes.

Plenty of people have blue eyes today, and there have been people with blue eyes for thousands of years. But believe it or not, that wasn't always the case. Thanks to the scientists at Copenhagen University, we now know that somewhere between 6, to 10, years ago, everyone had brown eyes, according to Science Daily. But at some point during that time, a mutation occurred on the OCA2 gene, which controls how much melanin we produce.

Specifically, this mutation essentially acted like a "switch" and "turned off" people's ability to produce brown eyes. Thus blue eyes were born! Not only did the team at the university identify the mutation that created blue eyes, but they also discovered that everyone with blue eyes has something in common. If you are the lucky owner of a set of cobalt peepers, chances are you've noticed that your eyes appear to change color, sometimes looking bluer or grayer — or even lighter or darker.

That was certainly the case with the famous movie actress Elizabeth Taylor , whose bright blue eyes could look violet when the light hit them just right. There's a reason blue eyes appear to change color, which is related to why they look blue in the first place. You guessed it: It all depends on how much light is both coming into and reflecting out of the eye, according to the American Academy of Ophthalmology.

Additionally, the color of the eye can look different depending on the color of clothing that a person wears, as well as the color and style of makeup that's applied around the eye. Contrary to what we might have once learned in school, it is possible for two blue-eyed parents to have a brown-eyed child, says Sturm. First there are genes that control the amount of melanin pigment in our irises — that's the part of our anatomy that acts like an aperture on a camera to control the amount of light that gets into the eye.

Around 74 per cent of our eye colour can be put down to a gene called OCA2 on chromosome This gene also contributes to hair and skin colour, but to a much lesser extent. A variation in the HERC2 gene, which sits right next to the OCA2 gene controls whether melanin is produced in the outer layer of the iris.

If you turn the switch on the eyes will be brown. If you turn it off they become blue," he says. Then there are genes that control the structure of the iris, such as it thickness and how much collagen it contains. Tags: eyes , evolution , anatomy. Email ABC Science. Use this form to email 'Why did humans evolve blue eyes? The genetics of eye color are very complicated. Even parents who have the same color eyes as each other could have a child with different colored irises.

Genetic research has shown that blue eyes probably only appeared in the last 6, to 10, years. Before then, everyone had brown eyes. Blue eyes have probably spread through the population just because some people like how they look and chose to have children with blue-eyed people.

Green and hazel eyes are a mixture of pigment color and color from scattered light, so they can also look different in different lighting conditions. Babies often do not have much pigment in their irises when they are born.

This is why their eyes can look very blue. For most children , eye color stops changing after the first year, but for some kids the color can continue to change for several more years. The Academy surveyed more than 2, Americans to determine what color eyes they have. 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. University of Copenhagen. January Iris color and associated pathological ocular complications: a review of epidemiologic studies.