Introduction. Eye colour, or more correctly iris colour, is often used as an example for teaching Mendelian genetics, with brown being dominant and blue being recessive.
Your children inherit their eye colors from you and your partner. It's a combination of mom and dad's eye colors – generally, the color is determined by this mix and whether the genes are dominant or recessive. Every child carries two copies of every gene – one comes from mom, and the other comes from dad.
Both parents have to pass along the blue eye gene in order for their child to have blue eyes. That doesn't necessarily mean that the parents themselves have to have blue eyes; it's possible they carry the gene, but it is recessive. However, a blue-eyed child is almost certain if both parents have blue eyes.
The brown eye form of the eye color gene (or allele) is dominant, whereas the blue eye allele is recessive. If both parents have brown eyes yet carry the allele for blue eyes, a quarter of the children will have blue eyes, and three quarters will have brown eyes.
The allele genes come in the form of brown, blue, or green, with brown being dominant, followed by green, and blue being the least dominant or what is called recessive. Given this information, you can determine what eye colors are dominant in the parents.
What is the rarest eye color? Green is the rarest eye color in the world, with only 2% of the world's population (and fewer than one out of ten Americans) sporting green peepers, according to the American Academy of Ophthalmology (AAO).
Flexi Says: Two brown-eyed parents (if both are heterozygous) can have a blue-eyed baby. If both the parents have brown eyes, then there is generally a 25% chance for their child to have blue eyes. Because both the brown-eyed parents have a recessive blue-eye gene and can pass it to the next generation.
Disadvantages of Blue Eyes
It does not indicate vision loss, but it can create some difficulty focusing or seeing clearly in bright lights. It may also cause pain around the eyes. Studies show that blue-eyed people may be more at risk for developing eye melanoma.
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.
People who are born blue-eyed are at higher risk of developing age-related macular degeneration. The research shows that there is less pigment in blue eyes, and green eyes for that matter, than there is in brown eyes. This means more light is able to penetrate blue eyes. This makes lighter eyes more sensitive to light.
Both parents with blue eyes: 99% chance of baby with blue eyes, 1% chance of baby with green eyes, 0% chance of baby with brown eyes. Both parents with green eyes: 75% chance of baby with green eyes, 25% of baby with blue eyes, 0% chance of baby with brown eyes.
If both parents have blue eyes, the children will have blue eyes. If both parents have brown eyes, a quarter of the children will have blue eyes, and three quarters will have brown eyes. The brown eye form of the eye color gene (or allele) is dominant, whereas the blue eye allele is recessive.
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.
A condition is considered Y-linked if the altered gene that causes the disorder is located on the Y chromosome, one of the two sex chromosomes in each of a male's cells. Because only males have a Y chromosome, in Y-linked inheritance, a variant can only be passed from father to son.
Most people feel as though they look more like their biological mom or biological dad. They may even think they act more like one than the other. And while it is true that you get half of your genes from each parent, the genes from your father are more dominant, especially when it comes to your health.
But what happens if a child has blue eyes and his parents both have brown eyes? The child inherited two blue genes; although neither parent had blue eyes, it was still part of their DNA. Blue eyes can skip a generation. In other words, this child's grandparents' eyes were probably blue.
The most prevalent place to find people with blue eyes (and where those percentages are considerably higher) is in the Scandinavian region. Europe also has pocket where people with blue eyes can be more commonly found. While the color blue is beautiful in the eyes, it is also evidence of less melanin production.
Consequently, many people think that blue eyes resemble a youthful appearance. It is also said that people with blue eyes have a calm and peaceful personality, and are representative of wisdom and knowledge. If you have blue eyes, it's time to brag! Psychologists say that you are immune to pain.
When broken down by gender, men ranked gray, blue, and green eyes as the most attractive, while women said they were most attracted to green, hazel, and gray eyes.
While blue eyes are more sensitive to light during the day, people with blue eyes tend to see better at night – unless there are bright lights. In that case, the lack of melanin makes them as sensitive to light at night as they are during the day.
Cultural ideals are also powerful.
"Our culture often idolizes a 'blond-haired, blue-eyed' person; this has been emphasized in movies and the media for decades," she tells mbg. "As such, the 'fun' and 'sexy' aspects attributed to a blue-eyed person are certainly a result of the heavy media influences."
Unfortunately, unless you were born with blue eyes, there aren't any ways to naturally change your eye color. However, you can create the illusion of having blue eyes. We've answered your questions about getting blue eyes so you can keep your eyes safe and healthy while experimenting with different colors.
There are plenty of blue-eyed Asians. This probably happens when the traditional blue-eyed allele comes into a family from a (possibly very distant) European ancestor. Blue eyes then resurface in a child generations later if they inherit the allele from both parents.
Approximately 8% to 10% of the global population have blue eyes. A 2002 study found that the prevalence of blue eye color among the white population in the United States to be 33.8% for those born from 1936 through 1951, compared with 57.4% for those born from 1899 through 1905.