How do people get the colors of their eyes?

Many people while getting to know the other person, pay the most of  attention to human eyes and metaphysicians believe that human eyes are the mirrors of the soul, while among scientists still exist debate about the emerging of different eye color.
blue eyes

Blue eyes

When poets compare beautiful eyes with the sea or sky, they had no idea how truly right they are. Eye color is not really the result of pigment, but scattered multi-colored light, so that only the blue color visible to the observer. On a clear day, sunlight releases molecules in the atmosphere, but in the short wavelengths. Blue light is scattered so almost ten times more efficiently than red.

Irises of people with blue eyes reflect light back in the same way. If the light that falls on the eyes is white and contains a combination of wavelengths, it is mainly the blue one that will be reflected back and you will be able to see it as observers. But indoors, where the light can be shifted toward the red end of the spectrum, it seems to us that the eye color changed since there is not enough of blue that will dominate.

brown_eye

Brown eyes

Unlike blue, brown eyes occurs much easier. The front layer of the eye with people with brown eyes has a lot of melanin, the pigment that is important for skin tanning as well. Most of the light that is falling on the eye is absorbed, and we see only the few that are eventually reflected as brown.

green eyes
Green eyes

Green eyes have slightly less melanin than brown. Most of the light is absorbed, but a small part still reflects and creates a color that is a mixture of brown and blue. Different focuses the eye can have different concentrations of color creating freckles.

grey eyes

Gray eyes

The gray color of the eyes occurs in a somewhat different way. Gray eyes have no melanin, and instead, the iris of the eye builds up collagen. As these particles are larger, they disperse the light waves more evenly, which results in a mixture of colors. Something similar is happening with water droplets in clouds.

Also, most infants initially have no melanin at all, even if their eyes will eventually turn brown. Their blue eyes color is darker than in adults, because the most blue-eyed adult people still have in their irises some larger particles that scatter spectrum of color, diluting so in the blue effect.

However, the genetics is what influences the color of the eyes. According to Mendel, genetics shows that the gene that is important for brown eyes is dominant and that the gene for blue eyes is recessive. Genes for other colors are usually quite differing. In fact, there are several genes that determine eye color, although the blue eyes thought to originate from a single ancestor. Adjacent genes OCA2 and HERC2 do the most of the work when it comes to determining the level of melanin, while the others could be responsible for the presence of other factors such as collagen.

 

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