Every expectant mother is interested in the question of what color her child's eyes will be, and whether the shade will change with age. But even after the birth of a baby, one cannot answer for sure. Let's try to figure it out - when the color of the eyes of newborns changes.
Genetic features of eye color
A child's eye color is one of the inherited traits that make him look like his father, mother, or next of kin, which are grandparents.
There are two concepts in the laws of genetics - dominance and recessiveness. The dominant trait is always stronger, in a child it suppresses the weaker one - recessive, but does not completely block it, allowing it to manifest itself in the next generation.
Brown eye color always prevails over green, green over gray and blue. However, if the baby has a blue-eyed grandfather or a gray-eyed grandmother, then the eyes can be blue or gray. This means that the trait is passed down through the generation.
It must be remembered that the laws of heredity are much more complex than those that we learn in school.
So, scientists have found that sections of six genes affect the color of the iris in a child, so there are thousands of options for only shades of one eye color. In addition to the classical rules of genetics, there are mutations, an example of which is purple eyes.
Anatomical and physiological features
What determines the color of a child's eyes? It is due to the amount of melanin. It is a special pigment found in the iris of the eye. There are more pigment cells in the posterior layer of the iris (with the exception of albinos) than in the anterior one.
This allows the rays of light not to scatter, but to be absorbed, due to which complex processes of formation of the visual image take place and the visual process is carried out.
Pigment cells begin to synthesize melanin only when exposed to light. According to how much melanin is contained in the structure of the anterior layer of the iris, the following eye colors are distinguished: blue, blue, gray, green, olive, brown, dark (black).
But there are a large number of their shades and tones. There are even scales of iris color classifications. The most famous are the Bunak scale and the Martin-Schultz system.
A few words should also be said about the features of the shades:
- gray eyes and eyes of all shades of blue and light blue contain practically no pigment. The light color of the vessels of the iris, combined with the scattering of light in its tissues, gives such a shade. The high density of collagen fibers in the structure of the anterior layer of the iris results in a lighter color;
- the green tint of the eyes appears due to the fact that the amount of melanin in them is higher than in gray and blue. In addition, the presence of lipofuscin pigment plays an important role in the creation of this color;
- the brown-eyed and dark-eyed have the highest melanin content, which allows them to absorb almost all the incident light.
Why does the eye color change in infants?
What eye color are babies born with? The prevailing opinion is that almost everyone is born with blue eyes. This is not entirely true. In newborns, eyes can be either sky blue or dark gray.
Even in twins, they can differ in shade. The initial color depends on the number of pigment cells. They begin to function immediately after birth, after the first rays of light hit the eye.
How does a child's eye color change?
Pay attention to baby's eye color at birth. If the eyes of a newborn have a light blue tint, then, most likely, radical changes should not be expected. If the baby has a dark gray color, then it will change to brown or even black.
When does a child's eye color change?
Its change can be noticed by the end of the first month of life. By the age of 2.5, when the eye color in babies almost completely changes, one can say who it looks like.
The final color of the eyes will not be until the age of twelve.
What unusual color options for eyes can there be?
- in the case of albinism (complete absence of pigment), the eyes are red. This is due to the visualization of the vessels of the iris;
- with heterochromia (hereditary mutation), the eyes have a different color. This usually does not affect their function;
- absence of the iris (aniridia) is a congenital developmental anomaly. It can be partial or complete, while visual acuity is low. Very often combined with hereditary pathologies.
Can diseases change eye color?
For a number of diseases, the iris can change its color:
- with uveitis, it becomes red due to stagnation of blood in the vessels;
- with a severe course of diabetes mellitus - red-pink due to the appearance of newly formed vessels;
- in the case of Wilson-Konovalov disease, a ring forms around the iris due to copper deposits;
- sometimes it is not the color that can change, but the shade, becoming darker (with siderosis or melanoma) or lighter (with leukemia or anemia).
Changes in eye color appear at the height of the disease, when the clinical picture and the main symptom complex do not give rise to doubt about the diagnosis.
At the end of the last century, the iridology method was very popular. Changes in the pattern, color and structure of the iris were studied.
It was believed that it was possible to diagnose almost all diseases occurring in the human body. Within the framework of evidence-based medicine, this method turned out to be absolutely unreliable, and therefore is not used today.
Changing the color or shade of the eyes is a matter of time. Don't waste such short days waiting for small changes. After all, we love the baby not for external signs, but for the fact that he is!
Article rating:
