Charlot123
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I’m not really sure what determines the intensity of blue. Here’s a quick breakdown of eye color in my immediate family:
Me - blue
Brother - brown
Mom - blue
Dad - hazel
Paternal Grandfather - blue
Maternal Grandmother - brown
Maternal Grandfather - blue
Maternal Grandmother - blue
I just found this interesting article about how eye color is determined:
Your Blue Eyes Aren’t Really Blue
Blue eyes get their color the same way water and the sky get their blue color. 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 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.
For people with green or hazel eyes, one or both of the layers of the iris also has some light brown pigment in it. The light brown pigment interacts with the blue light and the eye can look green or speckled.
Since blue eyes get their color from the light that’s coming in and being reflected back out, they really can appear as different colors depending on the lighting conditions. Green and hazel eyes are a mixture of pigment color and color from scattered light, so they can also look different in different lighting conditions.
Yes, it is very cool. Blue eyes have no “blue color” in them, their blue is the example of “structure color”. It is due to scatter of the light in colloidal media, similar like Raleigh scattering makes the sky blue. Funny that blue eyes are often compared to blue sky.
And IRL, it is all melanin, more or less melanin in the eyes.
The most interesting thing, we all, blue-eyed people, are the descendants of one woman, who was born 10000-8000 years ago in the NW area of the Black Sea steppes. The mutation is in the area next to OCA2 gene, producing melanin. The mutation created a switch, downplaying production of melanin in the eyes. Scientists also found out that all studied blue-eyed people carried the same mutation, and that they were connected matrilineally. So the first blue-eyes person was a woman. As 8-10 K ago, people were in general darker-skinned, so against such skin, blue eyes looked stunning. ))) I often think about that ancient beauty and her life.