Change Your Eye Color - Iris Color Facts

Color of Iris

The iris is usually strongly pigmented, with colors ranging from brown to green, blue, gray and hazel. Occasionally, the color is due to lack of pigmentation, as in the pink and white oculo-cutaneous albinism, or concealment of the pigment of blood vessels, as in the red of an abnormally vascularised iris (although human albinos generally have very light blue eyes, just as as the un-pigmented color of the human iris pale blue).

Despite thewide range of colors, there is only one pigment that contributes substantially to normal human iris color, than the dark pigment melanin. Structurally, this huge molecule is only slightly different from its equivalent found in skin and hair.

Genetic and physical factors, the iris color

Iris color is a very complex phenomenon, consisting of the combination of texture, pigmentation, connective tissue and blood vessels within the iris stroma, which togetheran individual epigenetic constitution. A person who "eye color" is actually the color of the iris, the cornea is transparent and the white sclera entirely outside the area of interest. It is a common misconception that the iris color is entirely due to its melanin pigment, but it depends only from brown to black.

Melanin is yellowish-brown to dark brown and black pigment cells in the stroma of the iris pigment epithelium, which in a thin but very opaque layer is located on the backthe iris. Most of the human iris also show a condensation of the brownish stromal melanin in the thin anterior border layer, which through its open position influence on the overall color.

The degree of dispersion of melanin, which in subcellular bundles called melanosomes, has some influence on the observed color, but melanosomes in the iris of humans and other vertebrates are not mobile and the degree of pigment dispersion can not be undone.

Abnormal clumping of melanosomesnot occur in disease and can lead to irreversible changes in iris color (heterochromia see below). Colors other than brown or black are due to selective reflection and absorption of the other stromal components. Sometimes lipofuscin, a yellow "wear and tear" pigment occurs in the visible eye color, especially in older or diseased green eyes (but not) in healthy and green eyes of the people.

Blue is one of the possible eye colors in humans. The "blue" allele in the existing Bey2 and GeyGenes of chromosome 15 is recessive. This means that both alleles of both genes does blue "blue-blue must have" in which a person with blue eyes. If one of the alleles have not "green blue" ( "" for Gey or "brown" for Bey2), then the person would be those colored eyes respectively.

Either as an allele (if not both) can be transmitted to the offspring, it is entirely possible that someone could have passed the no-blue eyes, blue-eyed children. Due to the recessive nature, this is a certainty if bothParents have blue eyes. Although this statement gives an idea of eye color delineation, it is incomplete, and all the factors to eye color and its changes are not fully understood.

Faking the iris color

Certain eye colors are sometimes to be especially attractive and motif-expressing contact lenses can be worn to a fancy natural eye color with another. They are required only rarely and almost never recommended by serious physicians, unless thePatient's retina needs extra protection, as in aniridia.

Since the introduction of machines that can automatically analyze the iris pattern, and their use at some airports as a security measure, it is reported that some people, colored contact lenses, or deliberate iris injury with lasers resorted to prevent personal identification.

Iris color as paternity test

As mentioned above, although it was much ado about the search for the genes for eye color, there is nosimple genetic determinism for such a complex feature, because there is more to iris color than pigmentation. Overall, there are no simple Mendelian inheritance in iris color. Consequently no serious test of paternity can be based on observations or even measurements of iris color, but will note that blue eyes are normally phenotypically recessive, so that a child of two brown eyes blue-eyed parents can some doubt about the to establish paternity.

Different colors in the twoEyes

Heterochromia (also known as a heterochromia iridis or heterochromia iridium) is an eye disease in which an iris is a different color from the other iris (complete heterochromia), or when the iris is part of a different color than the remainder (partial heterochromia or sectoral heterochromia).

Uncommon in humans, it is often an indicator of eye diseases such as chronic iritis or diffuse iris melanoma, but may also occur as a normal variant. Sectors or patchesstrikingly different colors in the same iris are less common. Alexander the Great and Anastasios The first were synchronized (dikoros, "with two pupils") heterochromias for their patent. In her case, this was not a true dicoria (two students in the same iris). Real polycoria is due to illness, but is most often due to previous injury or surgery.

In contrast, heterochromia and colored iris patterns are common in veterinary practice. Siberian Huskies show heterochromia byInbreeding, perhaps analogous to the genetically determined Waardenburg syndrome of humans.

Some white cat loves) (eg, white Persians may show striking heterochromia, with the most common pattern is a uniformly blue, the other green. Striking variegation within the same iris is also common in some animals, and the standard is in some ways.

Several herding breeds, particularly those with a blue merle coat color (such as Australian Shepherds and Border Collies) may showwell-defined blue areas within a brown iris as well as separate blue and darker eyes. Some horses (usually within the white, spotted, palomino or Isabell can show groups of breeds), yellow, brown, white and blue all in the same eye, without any sign of eye disease.

One eye with a white or bluish-white iris is also known as Zander

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