Scientists claim that eye color is genetically determined and is determined by the pigmentation of the iris. Indeed, the tone of the iris is inherited. There are not too many basic color options, but there are a great many shades.
What causes green eyes
According to scientific research and statistics, the rarest eye color is green. Its owners make up only 2% of the total population of the planet.
The green tint of the iris is determined by very little melanin. In its outer layer, there is a yellow or very light brown pigment called lipofuscin. In the stroma, a blue or cyan tint is present and diffused. The combination of diffuse shade and lipofucin pigment gives green eyes.
As a rule, the distribution of this color is uneven. Basically, there is a lot of its shades. In its pure form, it is extremely rare. There is an unproven theory that green eyes are related to the red hair gene.
Why green eyes are rare
In an attempt to find out why green eyes are rare today, one should turn for possible reasons to the Middle Ages, namely, to the time when the Holy Inquisition was a very influential institution of power. According to her doctrines, the owners of green eyes were accused of witchcraft, ranked among accomplices of the dark forces and burned at the stake. This situation, which lasted for several centuries, almost completely ousted the already recessive green iris gene from the phenotype of the inhabitants of Central Europe. And since pigmentation is an inherited trait, the chance of its manifestation is significantly reduced. So green eyes became infrequent.
Over time, the situation has somewhat leveled off, and now green-eyed ones can be found in Northern and Central Europe, and sometimes even in its southern part. Most often they can be seen in Germany, Scotland, Iceland and Holland. It is in these countries that the green eye gene predominates and, interestingly, is observed more often in women than in men.
In its purest form, namely the shade of spring grass, green is still a rarity. Basically, there are its diverse variations: gray-green and marsh.
In the countries of Asia, South America and the Middle East, dark eyes, mostly brown, prevail.
If we talk about the distribution and predominance of individual shades of the iris on the territory of Russia, the situation is as follows: the share of owners of dark eye color accounts for 6, 37%, transitional type eyes, for example, brown-green, have 50, 17% of the population, and representatives of light eyes - 43, 46%. All shades of green belong to them.
