1. In complete heterochromia, one iris is a different color from the other.
2. In sectoral heterochromia, part of one iris is a different color from its remainder.
3. In central heterochromia there is a ring around the pupil or possibly spikes of different colors radiating from the pupil.
Until 2007, it was believed that there was a hierarchy of eye color. Brown was dominant over green, which was dominant over blue.
Now it is proven that eye color is controlled by more than one gene; there have been 16 genes that contribute to eye color.
Green eyes...Blue/Grey? Hazel?
- Green is the least common eye color, but found most frequently in northern and central Europe. Green eyes possess low to moderate amounts of melanin.
However, green is actually not a pigmentation of the iris at all.
The main role of skin pigmentation seems to be to absorb ultraviolet radiation and this is true about the iris of the eyes too.
Rayleigh scattering is the dispersion of light off of air molecules, this helps determine eye color. This same scattering of light occurs in the sky which makes it appear blue, orange, pink, etc. and mountains in the distance appear purple or blue.
In the eye, this effect occurs in the top layer (stroma) of the iris. The blue optical effect of the Rayleigh scattering combined with the light to medium melanin pigmentation combines to make the eye appear green.
Changes in the light being scattered by the iris of lighter colored eyes will change the apparent color of the eyes.
This results in "chameleon eyes", or eyes that change color.
They fall into the amber, hazel, green, grey, and blue range. Some have incorrectly called this color eye hazel!
- Hazel eyes are due to a combination of Rayleigh scattering and a moderate amount of melanin in the iris' anterior border layer.
Hazel eyes often appear to shift in color from a brown to a green. It is sometimes very easy to confuse central heterochromia with the hazel eye color.
There is a huge variety of hazel eyes, they generally show a continuous shift in color from brown to green as you move outwards from the pupil. The boundary between two colors is more distinct in heterochromia.
A relatively small amount of people have green eyes, Non-proven facts and perceptions surrounding green eyes.
*Green eyes are said to be magical.*
*People with green eyes are the most passionate.*
*They are a powerful aphrodisiac.*