Gray eyes are anything but what many may associate with the color gray — like gloomy skies and drab and depressing color schemes. If you ever look deeply into a pair of gray eyes, what you may have thought about the color may just be quickly proven wrong. Once you look closely at gray eyes, you'll see that gray is a color that has depth and warmth. Far from being dull and dreary, gray eyes are mesmerizing and captivating. There's something rather alluring and perhaps just a little bit mysterious about gray eyes. Even people blessed with this rare eye color , though, may not know the fascinating story behind their eyes.
Eye color is a polygenic phenotypic character determined by two distinct factors: the pigmentation of the eye 's iris   and the frequency-dependence of the scattering of light by the turbid medium in the stroma of the iris. In humans, the pigmentation of the iris varies from light brown to black, depending on the concentration of melanin in the iris pigment epithelium located on the back of the iris , the melanin content within the iris stroma located at the front of the iris , and the cellular density of the stroma. The brightly colored eyes of many bird species result from the presence of other pigments, such as pteridines , purines , and carotenoids. The genetics and inheritance of eye color in humans is complicated. So far, as many as 15 genes have been associated with eye color inheritance.
Hunting for information on grey eyes? Hoping to find out how many people have grey eyes on the planet? When one considers that an estimated 7 billion people live on planet earth, this means only ,, million humans have grey as their eye color. Grey eyes can come in different shades, including hues of smokey blue, green and in some cases, hazel-brown. Much depends on the person, lighting, atmospheric conditions and x-variables.
Scientists know a lot about the genetics of eye color. But mostly about blue, green and brown eyes. Not many scientists have studied the differences between blue and gray eyes. This is probably because it is likely that the genetics of the two are very similar. But as you will read later on they are not exactly the same. Although we do not know the exact genes that cause gray vs. When people talk about eye color, they are talking about the color of the part of the eye called the iris. The color comes from dye-like molecules called pigments. Pigments are what give nature all of her colors.