How Rare Are Blue Eyes?
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1. Only 8 Percent of the World’s Population Has Blue Eyes 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.
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.2. There is No Blue Pigment in Blue Irises 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.3. Blue Eyes are More Sensitive to Light 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.
Since blue eyes contain less melanin than green, hazel or brown eyes, photophobia is more prevalent in blue eyes compared to darker coloured eyes. For these reasons, having less melanin in your irises means that you need to protect your eyes more from the sun’s UV rays.
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.4. All Blue-Eyed People May Have A Common Ancestor 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.
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? A 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.
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). 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.
According 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. They have all inherited the same switch at exactly the same spot in their DNA.” 5.
Blue Eyes at Birth Doesn’t Mean Blue Eyes For Life While blue eyes may be rare, they’re among the most common eye colours at birth. Since the human eye does not have its full adult amount of pigment at birth, most Caucasian babies are born with blue 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.6.
People With Blue Eyes May Have a Higher Risk of Alcoholism A new study suggests that individuals with blue eyes are at a higher risk for alcohol dependency compared to those with darker eyes. Therefore, this finding adds further evidence to the idea that alcoholism has a genetic component.
- A 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.
- This research suggests that alcoholism has a genetic component linked to genetic sequences that determine eye colour, which may help explain the association.
However, at this stage, the reason for the correlation is still unknown and further research is required to fully understand this correlation in the findings.7. You Can’t Predict the Colour of Your Child’s Eyes Since it was once believed that eye colour — including blue eyes — was a simple genetic trait, many people used to believe that blue-eyed people could only have blue-eyed children.
Before geneticists fully understood how human eye colour inheritance works, a child’s eye colour to used be used as a paternity test — based on the assumption that you could predict a child’s eye colour if you knew the colour of the parents’ eyes and perhaps the colour of the grandparents’ eyes. But geneticists now know that this concept is far more complicated, as eye colour is influenced by an interaction of as many as 16 different genes — not just one or two genes as once thought.
Additionally, the anatomic structure of the iris can also influence eye colour to some degree. In summary, it’s impossible to know for sure if your children will have blue eyes. Even if you and your partner both have blue eyes, that’s no guarantee your child’s eyes will also be blue.
What eye color is the rarest?
Green Eyes – Green is considered by some to be the actual rarest eye color in the world, though others would say it’s been dethroned by red, violet, and grey eyes. 
Green eyes don’t possess a lot of melanin, which creates a Rayleigh scattering effect: Light gets reflected and scattered by the eyes instead of absorbed by pigment. This effect makes the eyes look green, but they don’t actually have green pigmentation.
Are blue eyes rarer than grey?
Other eye colors – If you’ve been doing the math, you already know that these colors only add up to 99%. What about the other 1%? There are a few unique colors, and combinations of colors, that make up this group: the rarest of the rare. Some people may group gray eyes (also spelled grey eyes) with blue eyes.
- Their low melanin content is similar, but in fact, gray irises are significantly more rare than standard blue eyes.
- If you look closely, you might even spot streaks of brown, amber and gold within the gray.
- Even less common is a condition called heterochromia — different colored eyes.
- It’s usually the result of a harmless genetic mutation, but it can also be caused by underlying disorders and injuries.
People who have albinism lack most or all melanin, giving their skin, hair and eyes a very light appearance. This often results in light blue eyes but can rarely show as pink or pale red-colored eyes, when a complete absence of melanin causes tiny blood vessels to become visible. Page published on Saturday, September 5, 2020
Are dark blue eyes rare?
What Causes Blue Eyes? – Blue eyes have fascinated people for centuries. In cultures around the world, they are seen as beautiful yet also cold. Blue eyes are rare, making up just 8-10% of the world’s population. Blue eyes are caused by a relative lack of melanin in the iris.
Did Elizabeth Taylor have purple eyes?
Did Elizabeth Taylor have violet eyes? – 
Did Elizabeth Taylor really have violet eyes? (Image credit: Getty/ Keystone-France / Contributor) These days, thanks to colored contact lenses, anyone can have violet-colored eyes, Taylor didn’t come by her purple peepers that way; the first tinted contact lenses weren’t commercially available until 1983.
- Taylor’s eye color was the real deal.
- The appearance of the iris, the colored ring that’s around the eye’s black pupil depends on how much of the natural pigment melanin it contains.
- The more melanin in your iris, the darker your eyes will look (melanin levels are determined by your genes ).
- For example, the irises of a person with dark brown eyes have more melanin than the eyes of a green-eyed person.
Taylor’s eyes had a very specific, and rare, amount of melanin, according to The List (opens in new tab), “There are various shades of blues and grays, with many in-between. Violet may have been her typical pigmentation,” Norman Saffra, chairman of the ophthalmology department at the Maimonides Medical Center (opens in new tab) in Brooklyn, N.Y., told Live Science,
- It’s possible to have that eye color; it all depends on the amount of melanin.” Eye color can also appear to change based on the eye’s light absorption, Saffra said.
- For example, wearing a white shirt will reflect light off of the iris and make its color look slightly lighter.
- Makeup can also “bring out” certain colors in the eyes.
Taylor was often photographed wearing blue or purple eyeshadow to compliment her eyes’ naturally violet hue, or dark brown eyeshadow and black eyeliner to contrast against and play up their unique color.
Can 2 blue-eyed parents have a brown eyed child?
Can two parents with blue eyes have a child with brown eyes? Yes, blue-eyed parents can definitely have a child with brown eyes. Or green or hazel eyes for that matter. If you stayed awake during high school biology, you might find this answer surprising.
- We were all taught that parents with blue eyes have kids with blue eyes.
- Every time.
- This has to do with the fact that blue eyes are supposed to be recessive to brown eyes.
- This means that if a parent has a brown eye gene, then that parent will have brown eyes.
- Which makes it impossible for two blue-eyed parents to have a brown-eyed child – they don’t have a brown eye gene to pass on! In fact, this is the model we used for our eye color calculator.* And that we talk about extensively here at Ask a Geneticist.
Blue-eyed parents can have kids with brown eyes. (Image via Shutterstock) Now we aren’t being dishonest or trying to hide anything by presenting this model. It works great most of the time. But as with anything genetic, there are always exceptions. For example, DNA can and does change between generations.
So if a change happened that turned a blue eye color gene into a brown one, then blue-eyed parents could have a brown-eyed child. As you might guess, this sort of thing is pretty rare. Too rare to explain all the exceptions we see with eye color. So something else must be going on. That something is most likely other genes involved in eye color that we don’t know about.
Eye color used to be presented as a fairly simple trait. A big part of the model was the idea that we had an eye color gene that came in two varieties – brown and blue. Geneticists represented the brown version as “B” and the blue version as “b”. The model also said that blue (b) was recessive to brown (B).
- This matters because it is an explanation for how brown-eyed parents can have a blue-eyed child.
- See, we have two copies of each of our genes – one from each biological parent.
- This means there are three possible combinations for this eye color gene: BB, Bb, and bb.
- BB is of course brown and in this model, bb would be blue.
Since blue is recessive to brown, Bb people have brown eyes. But they can pass a “b” down to their kids, who might end up with blue eyes. Now eye color is obviously more complicated than this. This model doesn’t explain green eyes for example. Scientists added a second gene to try to explain green eyes but we don’t need to go into that here ( to learn more about the two-gene model).
| Genes | What it Means |
| BB | Brown eyes |
| B b | Brown eyes |
| bb | Not brown eyes |
Again, bb people should not be able to pass on brown eyes to their kids. But we know they can. Which means that this model is incomplete (or wrong). The results I just put into the previous table are theoretical and based on the model I talked about. Here are some actual results I adapted from ‘s website:
| Genes | What it Means in Europeans |
| BB |
|
| B b |
|
| bb |
|
As you can see, the original model holds up pretty well for BB and bb people. Most BB people have brown eyes and most bb people don’t. But the model clearly doesn’t explain the following:
- 1% of bb people have brown eyes
- 1% of BB people have blue eyes (and 14% have green)
- 44% of Bb people do not have brown eyes
The biggest disconnect is with Bb people. Only 56% have brown eyes. If this holds up, I am not sure we can even call blue and green recessive to brown. Whatever the reason, these data give some clues about how two blue-eyed parents might have a brown-eyed child.
- For example, imagine two parents are Bb and have blue eyes.
- They each pass a B down to one of their children.
- That child will be BB and most likely have brown eyes.
- This example uses known data to show how blue-eyed parents might have a child with brown eyes.
- But it doesn’t explain why a Bb person has blue eyes in the first place.
To do this, we need to guess what other genes may be doing. And how they might be affecting the original eye color gene. Going into detail about these possibilities would need more space than I have here! And in the end, the truth is that eye color is a complex trait that we don’t fully understand yet.
What causes blue eyes?
Is eye color determined by genetics? A person’s eye color results from pigmentation of a structure called the iris, which surrounds the small black hole in the center of the eye (the pupil) and helps control how much light can enter the eye. The color of the iris ranges on a continuum from very light blue to dark brown.
Most of the time eye color is categorized as blue, green/hazel, or brown. Brown is the most frequent eye color worldwide. Eye color is determined by variations in a person’s genes. Most of the genes associated with eye color are involved in the production, transport, or storage of a pigment called melanin.
Eye color is directly related to the amount of melanin in the front layers of the iris. People with brown eyes have a large amount of melanin in the iris, while people with blue eyes have much less of this pigment. A particular region on plays a major role in eye color.
Within this region, there are two genes located very close together: and HERC2, The protein produced from the OCA2 gene, known as the P protein, is involved in the maturation of melanosomes, which are cellular structures that produce and store melanin. The P protein therefore plays a crucial role in the amount and quality of melanin that is present in the iris.
Several common variations (polymorphisms) in the OCA2 gene reduce the amount of functional P protein that is produced. Less P protein means that less melanin is present in the iris, leading to blue eyes instead of brown in people with a polymorphism in this gene.
A region of the nearby HERC2 gene known as intron 86 contains a segment of DNA that controls the activity (expression) of the OCA2 gene, turning it on or off as needed. At least one polymorphism in this area of the HERC2 gene has been shown to reduce the expression of OCA2 and decrease P protein production, leading to less melanin in the iris and lighter-colored eyes.
Several other genes play smaller roles in determining eye color. Some of these genes are also involved in skin and hair coloring. Genes with reported roles in eye color include ASIP, IRF4, SLC24A4, SLC24A5,, TPCN2,, and, The effects of these genes likely combine with those of OCA2 and HERC2 to produce a continuum of eye colors in different people.
Researchers used to think that eye color was determined by a single gene and followed a simple inheritance pattern in which brown eyes were dominant to blue eyes. Under this model, it was believed that parents who both had blue eyes could not have a child with brown eyes. However, later studies showed that this model was too simplistic.
Although it is uncommon, parents with blue eyes can have children with brown eyes. The inheritance of eye color is more complex than originally suspected because multiple genes are involved. While a child’s eye color can often be predicted by the eye colors of his or her parents and other relatives, genetic variations sometimes produce unexpected results.
Several disorders that affect eye color have been described. is characterized by severely reduced pigmentation of the iris, which causes very light-colored eyes and significant problems with vision. Another condition called affects the pigmentation of the skin and hair in addition to the eyes. Affected individuals tend to have very light-colored irises, fair skin, and white or light-colored hair.
Both ocular albinism and oculocutaneous albinism result from mutations in genes involved in the production and storage of melanin. Another condition called heterochromia is characterized by different-colored eyes in the same individual. Heterochromia can be caused by genetic changes or by a problem during eye development, or it can be acquired as a result of a disease or injury to the eye. Sturm RA, Duffy DL, Zhao ZZ, Leite FP, Stark MS, Hayward NK, Martin NG, Montgomery GW. A single SNP in an evolutionary conserved region within intron 86 of the HERC2 gene determines human blue-brown eye color. Am J Hum Genet.2008 Feb;82(2):424-31. doi: 10.1016/j.ajhg.2007.11.005.
Epub 2008 Jan 24. PubMed:, Free full-text available from PubMed Central:, Sturm RA, Larsson M. Genetics of human iris colour and patterns. Pigment Cell Melanoma Res.2009 Oct;22(5):544-62. doi: 10.1111/j.1755-148X.2009.00606.x. Epub 2009 Jul 8. Review. PubMed:, White D, Rabago-Smith M. Genotype-phenotype associations and human eye color.
J Hum Genet.2011 Jan;56(1):5-7. doi: 10.1038/jhg.2010.126. Epub 2010 Oct 14. Review. PubMed: : Is eye color determined by genetics?
Can you change eye color?
Can I Change My Eye Color Permanently and is it Safe? – Permanent changes to eye color can be achieved through iris implant surgery, corneal pigmentation, and laser eye color change. Iris Implant Surgery is a procedure that inserts a prosthetic iris into the eye.
- It was originally developed to treat iris defects such as albinism and aniridia.
- It is not, however, approved for cosmetic purposes to permanently change eye color.
- Iris implants that are used for This procedure for non-medical and cosmetic purposes are considered extremely risky and haves thus been prohibited in the US by the FDA.
Risks include reduced vision or blindness, corneal injuries leading to vision problems, and cataracts. The risks for permanent vision loss and blindness far outweigh the cosmetic benefits of an eye color change. Keratopigmentation or Corneal Tattooing involves injecting or tattooing pigmentation into the cornea to create the perception of various colors in the iris.
Originally used for problems with corneal opacity caused by leucoma or keratitis, this procedure is not recommended for cosmetic enhancement to eye color. It is a semi-permanent option and complications include infection of the cornea, light sensitivity, and risk of inadvertent globe penetration via entry into the anterior chamber.
Laser Eye Color Change uses a laser beam to remove pigment from the iris surface to reveal the blue and green colors lying underneath the melanin. In the US, the STRŌMA procedure was first patented in 2001 and continues to be in research and development.
The procedure permanently changes eye color and can take several treatments to achieve the desired effect. In 2015, the American Academy of Ophthalmology (AAO) warned consumers about the need for clinical trial testing to determine potential safety risks associated with laser surgery to change eye color.
The AAO has expressed concerns about how liberating pigment could cause glaucoma, a group of eye conditions that damage the optic nerve, and uveitis, a form of eye inflammation. At this time, it is not recommended or safe to pursue procedures for permanently changing eye color.
Do blue eyes fade with age?
The Claim: Eye Color Can Change as We Age (Published 2005) Really?
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THE CLAIM – Eye color can change as we age. THE FACTS – It can bend light, bring the world into focus, and next to the human brain may be our most complicated organ. But for many people the most intriguing feature of the human eye is simply its color. Can it really change for no apparent reason? In most people, the answer is no.
Eye color fully matures in infancy and remains the same for life. But in a small percentage of adults, eye color can naturally become either noticeably darker or lighter with age. What determines eye color is the pigment melanin. Eyes that have a lot of it in the connective tissue at the front of the iris, called the stroma, are darker, while those that have less tend to be lighter.
The levels of melanin generally remain the same throughout life, but a few things can change them permanently. The first is a handful of ocular diseases like pigmentary glaucoma. Another is a condition called heterochromia, or multicolored eyes, which affects about 1 percent of the population and is often caused by traumatic injuries.
- An example of this can be seen in the rock star David Bowie, who attributes his contrasting eye colors, hazel and light blue, to a blow to the face as a child.
- The third cause appears to be genetics.
- A study in 1997, for example, looked at thousands of twins and found that 10 percent to 15 percent of the subjects had gradual changes in eye color throughout adolescence and adulthood, which occurred at nearly identical rates in identical twins.
THE BOTTOM LINE – Eyes can change color in some people because of genetics or injury. ANAHAD O’CONNOR Really? [email protected] : The Claim: Eye Color Can Change as We Age (Published 2005)
How old are blue eyes?
Why Did Blue Eyes Evolve? | Resource Center Blue eyed people make up an estimated 8% of the population. However, in Northern European countries, such as Iceland, blue-eyed individuals find themselves in the majority. The question is why humans evolved to have blue eyes in the first place? Ultimately it must have started out as a genetic mutation, but what led this mutation to be passed on to offspring and to spread? The short answer is that scientists are not exactly sure.
Can you have black eyes?
What is a black eye? – A black eye is a bruise in the tissues around the eye. Depending on how it happened, it may be a good idea to get it checked out by a doctor in case you have a more serious injury. A black eye is also known as periorbital haematoma.
- A black eye develops when fluids collect in the tissues around the eye.
- The bruising and blue and purple discolouration are caused by broken blood vessels under the skin.
- These tissues will usually be swollen too.
- The eye itself is not usually damaged.
- A black eye can often look worse than it actually is.
That’s because the skin around the eye is quite loose, thin and transparent, meaning it puffs up easily and even a little pooling of blood can cause discolouration. Sometimes you might also have bleeding inside your eye, and this is a medical emergency that needs treatment.