The Color of the Eyes. Eye color is a polygenic trait that is determined by the amount and type of pigments present in the iris of the eyes. Although there appear to be three genotypic eye colors (brown, green, and blue), humans and other animals have many phenotypic variations in eye color. It is a complex process in which several genes intervene in the final result, and there are cases such as violet eyes, or people with one eye of each color.
Summary
[ hide ]
- 1 Change in eye color
- 2 The Eyes
- 3 The Look
- 4 The color of the eyes
- 1 Chestnut
- 2 Amber
- 3 Hazelnut
- 4 Green
- 5 Blue
- 5 See Also
- 6 Sources
Change in eye color
Newborns – especially those with a caucasoid leukoderm phenotype – often have a minimal amount of melanin in the anterior part of the iris. As the eye is exposed to sunlight, the melanocytes in the iris begin to produce melanin, and the eye color begins to change towards its adult coloration, reaching at least 50% of the adult pigment density at the age of three.
The eyes
The eye is a fundamental organ of the human body that is often undervalued. Thanks to the eyes, you can perceive the world, see loved ones, appreciate beauty and know the surroundings. Through the eyes you can perceive the colors, shapes and feelings of others.
Apart from its main function, which is sight, the eyes are very important because they form a very special part of the face. The eyes and gaze convey many feelings to the point that many say that the eyes are the window of the soul. Through the eyes you can transmit joy, hope, emotion, love and also sadness, despair or anguish. Many people find it very difficult to hide their feelings because their eyes and gaze give them away. For this reason, it is common for people to look into the eyes of another person to know what they are thinking or what they really feel. For many people it is important to be with people who are able to look into the eyes and hold the gaze and often those people who cannot stare into the eyes are not trusted.
The look
The looks also play a very special role in other matters. A glance can communicate much more than a few words, and communicate things that are often difficult to describe with words, such as the tenderness that a mother’s gaze towards her baby reflects. In love, glances also have a fundamental role. With a look you can conquer, you can seduce and you can also be seduced.
Eye color
There are three elements of the iris that contribute to giving it its color: the pigment of the iris epithelium, the melanin of the iris stroma and the cellular density of the iris stroma. In all types of eye colors, the pigment of the iris epithelium is always black, due to eumelanin. Color variations come from the stroma pigment and how much light it absorbs according to its density.
Brown
Brown, brown, or brown eyes contain large amounts of melanin in the anterior part of the iris , which serve to absorb large amounts of light, especially the shorter wavelengths of light. It is one of the most common phenotypes for eye color in humans.
Amber
The eyes of amber or honey color are of a tone that can go from yellowish to reddish gold and copper tint. Amber is an intermediate color between brown and hazelnut. The pigment responsible for this coloration is lipochrome , also called fuscus pigment, and which is also present in green eyes. Genetically, there is no explanation for this coloration.
Hazelnut
Hazelnut eye color is an intermediate shade between brown and green. It can also contain sectors where chestnut, amber or green are clearly presented. From the genetic point of view, an explanation is not clear either.
Green
Green eyes are the product of moderate amounts of melanin. Green is an intermediate color between brown and blue or gray tones.The genes involved in this effect are EYCL1 and EYCL3. This is how the dominant allele for EYCL1, conjugated with any allele for EYCL3, with the exception of the dominant allele of the latter, results in the color green eyes.
blue
Blue or light blue eyes contain low amounts of melanin in the front part of the iris. They are produced, and including the previous characteristic, because the stroma, a transparent tissue composed in part of collagen, gets in the way of light when it is reflected by the epithelium of the iris to the outside.
