Blue Eyes & Melanin Sunglasses
ALL mammal irises are BROWN except the irises of an albino, which are PINK.
The deactivated OCA2 gene responsible for “blue” eyes removes most of the brown melanin pigment and reduces the size of the remaining melanin particles to a maximum of one micron (1/400,000,000 of an inch).
By comparison, it takes several thousand microns to produce deep red.
This reduction creates Tyndall scattering, named after British physicist John Tyndall (1820-1893).
The shorter blue light rays are reflected back to the observer by the remaining microscopic melanin particles.
There are NO pigments in blue eyes, just as there are NO pigments in a blue aura.
All blue irises — and blue auras — are created by reflected blue light.
Blue jays, bluebirds, blue butterflies, blue dragonflies, as well as blue eyes, are all free of blue pigment.
If you beat on a blue jay feather with a hammer, the feather turns black when the surface optical effect is destroyed.
There’s also no such thing as a white bird feather.
In birds, “white” and “blue” are schemochromes, optically produced colors from the coherent scattering of light, the same interference pattern that causes the “color” of an oil slick.
A parallel phenomenon, Rayleigh scattering, the selective scattering of light, makes the sky and the ocean appear blue.
There’s no chemistry involved in a blue sky — only the elastic scattering of light named after British physicist Lord Rayleigh (1842-1919).
Green eyes are caused by an increase in the size and quantity of melanin particles, just as waterborne micro-organisms (phytoplankton, etc.) change the color of the ocean from blue to green.
Light brown and dark brown eyes are caused by a still further increase in the size and quantity of melanin particles.
However, alien black, brown, orange, and/or yellow pigmentation in an iris DOES indicate toxic phenotypic (not genotypic) disorders, but normal brown irises are actually “sunglasses” for the eyes.
The idea that brown eyes are toxic appeared because iridology was originally developed by German racial hygienists.
Blue eyes, blond hair, and fair skin were defining features of the so-called Master Race, also known as the Nordic Race, Aryan Race, Nordic-Aryan Race, and Nordic-Atlantean Race.
Diffractional “structural” blue is more common on Earth than pigmentary blue.
Patricia Sloane (The Visual Nature of Color, 1989) wrote …
“The Tyndall blues, explained in terms of diffraction, account for many of the blue colors seen in beetles, butterflies, birds, and mammals. Named after the Irish physicist John Tyndall, who discussed the phenomenon in 1869, they provide another example of the ubiquitous visual affinity between blue and black. The Tyndall blues might as appropriately have been called the Tyndall blacks. They are typically created when a layer of melanin, a black pigment, is overlaid by translucent ridges, scales, or other structures that scatter light. A blue wing feather from a blue jay, for example, contains no blue pigment. When crushed, the feather is reduced to a black, not blue, powder.”
Denis Llewellyn Fox (Animal Biochromes and Structural Colours: Physical, Chemical, Distributional & Physiological Features of Coloured Bodies in the Animal World, Second Edition, 1976) wrote …
“The iris, seat of colour in the eye, is representative of the general type of biocolloid which, if unpigmented, gives rise to structural blues in integumentary tissues of birds and mammals. Of the iris’s structure we find a good discussion by Roberts (1880), who points out that the coloured portion of the eye is made up of a thin membrane, bearing unstriped muscular fibres, nerves and blood capillaries, all incorporated in a fine, delicate reticulum of fibrous tissue. In normal eyes the uvea, containing a layer of brown and black melanin, lines the back of this membrane, behaving as a light-absorbing curtain, with the result that irides bearing no additional pigment in the main body of their structure manifest the blue colours of scattering. Brown eyes possess an additional layer of yellow and perhaps ruddy brown pigment on the outer surface of the iris, and may also have deposits of the dark melanin among the interior fibrous structures. In green eyes there is a relatively uniform distribution of the yellow pigment over the outer surface of the iris. Lacking additional dark pigment aggregates at the surface or in the interior, the pigmentary yellow and structural blue are combined to yield various shades of green. Increasing concentrations of yellow and darker melanins in the surface and inside of the iris lead to hazel, brown and black colours. Albino eyes lack melanin pigment in both the uveal layer and the internal stroma. They consequently appear pink, owing to the reflexion of red rays, from the haemoglobin in the fine capillaries, through the semi-transparent, light-scattering fibrous tissues. In this instance also, as with the opaque melanins, the red pigment masks the easily affected blue colour of scattering, else such an eye should manifest a purplish hue.”