What determines eye color?

As children inherit eye color?Is it possible to predict what it will be in a child?Why are they albinos pink?If both parents with brown eyes, then whether they be born, blue-eyed kid?How is the color of the iris?These questions are relevant at all times.The answer to them is contained in the set of internal and external signs of the body formed on the basis of genotype, as well as acquired as a result of individual development.What does this mean, and what determines the color of the human eye?

This characteristic is determined by the pigmentation of the iris (iris), consisting of ectodermal (rear) and mesodermal (front) layers.That is the color of the human eye depends on the nature of the distribution fustsina (he contributes to the development of the visual pigment absorbs light and prevents its dispersion and reflection, resulting in improved clarity of vision of the image) in the pigment cells of the backing layer and melanin (natural dark matter) in the pigment-containing and light-reflectingcel

ls (chromatophores) of the front layer.Also affects the color of the state of the vessels and the fibers of the iris, a different number and nature of the pigment, which in turn determines Genet.Eye color is caused by genes.But not all of them are studied.

Melanin is the colored substance, it affects not only the color of the eyes, and hair and skin tones.Yet, what determines eye color?The more melanin contained in the mesodermal layer, the darker the iris, and the less it is distributed in the pigment cells of the anterior layer of the iris, the lighter it will be.There melanin brown and black (or eumelanin), and yellow (or pheomelanin).The nature and quantity of this natural substance and its distribution of certain genes responsible.As a result, coloring of the iris may be blue, blue, gray, green, amber, marsh, Carey Is Black.The child will inherit the similarity with the parent having dominant signs (brown, light brown and green) and he will not get the eye color from a parent recessive traits (blue or gray).

have blue eyes back layer is colored blue due receptacles formed collagen fibers, the front layer has a minimum content of melanin.Blue differ from whitish blue greater density of fibers: the higher the density, the brighter the iris.Gray eyes is due to a greater density of collagen.The front layer of the green there is a small amount of melanin, because of the blue color of the backsheet, iris is nonuniform green and different shades.What determines eye color amber?The pigment lipofuscin ensures their uniform color.With moderate melanin content in the outer layer of the eye become swamp or walnut.Brown happen when chromatophores contains a lot of melanin.For black characterized by a high content of pigment, which completely absorbs light.In albino he is absent, and the iris appear pink or red due to the reflection color of the blood vessels.

Newborns have a blue iris, but it can darken over the next few years.Why is this, and what determines the color of the eyes of the child?Melanin in the body at the time of birth of the fetus is not produced, since not required until this time protection against ultraviolet rays, which is performed dark pigment.Its main purpose - is to prevent radiation damage to body tissues.After birth, begins production of melanin by specialized cells (melanocytes).Therefore, the true color of the eyes of the child may be determined not earlier than in three years, although changes are sometimes up to 10-12 years.Adults can also change color of the iris under the influence of drugs or because of ill health.For example, there is a yellowish color due to the accumulation of lipofuscin.

usually considered dominant brown eyes and blue - recessive.But modern science has proven that it is not so simple.The darker the color, the more it dominates: brown over green, green over blue.But not always be brown-eyed child, if the iris from mum and dad brown.In children, it can differ.This is usually caused by faulty development of pigment transport, local trauma, or in the womb or shortly after birth, as well as a genetic disease.