Unlike brown eyes, blue eyes have low concentrations of melanin in the stroma of the iris, which lies in front of the dark epithelium. source
Unlike brown eyes, blue eyes have low concentrations of melanin in the stroma of the iris, which lies in front of the dark epithelium.
In humans, the inheritance pattern followed by blue eyes is considered similar to that of a recessive trait. source
In humans, the inheritance pattern followed by blue eyes is considered similar to that of a recessive trait.
In 2008, new research tracked down a single genetic mutation that leads to blue eyes. "Originally, we all had brown eyes," said Eiberg. source
In 2008, new research tracked down a single genetic mutation that leads to blue eyes. "Originally, we all had brown eyes," said Eiberg.
Eiberg and colleagues suggested in a study published in Human Genetics that a mutation in the 86th intron of the HERC2 gene. source
Eiberg and colleagues suggested in a study published in Human Genetics that a mutation in the 86th intron of the HERC2 gene.
Blue eyes are common in northern and eastern Europe, particularly around the Baltic Sea. source
Blue eyes are common in northern and eastern Europe, particularly around the Baltic Sea.
Blue eyes are also found in southern Europe, Central Asia, South Asia, North Africa and West Asia. source
Blue eyes are also found in southern Europe, Central Asia, South Asia, North Africa and West Asia.
A study taken in 1911 found that 53.7% of Ukrainian Jews had blue eyes. source
A study taken in 1911 found that 53.7% of Ukrainian Jews had 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. source
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.
As of 2006, one out of every six people, or 16.6% of the total population, and 22.3% of whites, has blue eyes. source
As of 2006, one out of every six people, or 16.6% of the total population, and 22.3% of whites, has blue eyes.
Blue eyes are continuing to become less common among American children. source
Blue eyes are continuing to become less common among American children.
Blue eyes are rare in mammals; one example is the recently discovered marsupial, the blue-eyed spotted cuscus (Spilocuscus wilsoni). source
Blue eyes are rare in mammals; one example is the recently discovered marsupial, the blue-eyed spotted cuscus (Spilocuscus wilsoni).
While some cats and dogs have blue eyes, this is usually due to another mutation that is associated with deafness. source
While some cats and dogs have blue eyes, this is usually due to another mutation that is associated with deafness.
The mutation found in blue-eyed solid white cats (where the coat color is caused by the gene for "epistatic white") is linked with deafness. source
The mutation found in blue-eyed solid white cats (where the coat color is caused by the gene for "epistatic white") is linked with deafness.
In the blue-eyed Ojos Azules breed, there may be other neurological defects. source
In the blue-eyed Ojos Azules breed, there may be other neurological defects.
Blue-eyed non-white cats of unknown genotype also occur at random in the cat population. source
Blue-eyed non-white cats of unknown genotype also occur at random in the cat population.
Like blue eyes, gray eyes have a dark epithelium at the back of the iris and a relatively clear stroma at the front. source
Like blue eyes, gray eyes have a dark epithelium at the back of the iris and a relatively clear stroma at the front.
