When we talk about eye color, we are actually referring to the iris pigmentationa living tissue of the eye that reacts to light like the iris of a camera.
The iris surrounds the pupil, the hole in the center of the eye through which light enters, and which even without coloration we perceive as black. The white part of the eye is made up of the sclera and the conjunctiva, the tissue that encompasses the eyeball, is exterior and has no relation to the iris. This part of the eye is white and is seen to be vascularized with capillaries..
Typically, in the first days of life, the eyes of babies have a grayish hue due to the immature melanocytes that are responsible for pigmentation of the iris.
The maturation of the melanocytes and the solar stimulus generate the melanin that gives color to the iris. evolution to more or less pigmentation it will be what makes the color of the eye more or less dark. Although there are babies born with a dark iris color, this is less frequent. In these cases, the final color will be brown or black.
After birth, what happens is that ‘colors’ the iris with melanin produced by melanocytes As they develop, the smaller this coloration is, the lighter the color of the eye is, something that will be marked by the genetic inheritance transmitted by the parents.
Actually, when it comes to blue eyes, a recessive (non-dominant) gene is involved, which is why there is a predominance of dark eyes over light ones.
Is it possible that both parents have dark eyes and their child has blue eyes? Yes, the specialist points out, this happens when both parents have a father from whom they have inherited this recessive gene for light-colored eyes.
Serious disorders, the red eye effect and Bowie
Regarding possible anomalies in ocular development, parents should rule out the existence of white pupils in the baby’s iris, which is called leukocoria, since this could indicate the existence of congenital cataracts or a tumor in the retina called retinoblastoma.
What concerns to exposure of babies to camera flashalthough it is likely to bother them more than adults, it does not harm the vision of newborns
It is precisely in photographs taken with flash that a well-known effect on eye color occurs. ANDThe red color of the pupil that we observe in the photographs with flash is that of the blood vessels inside the eye when light passes through the pupil and reaches the retina.
Some disorders or physical characteristics can also cause peculiar phenomena to occur in the coloration of the eyes. Thus, there are certain chronic inflammatory processes that can change the color of one of the eyes, something that can occur in older people after repeated episodes of uveitis. There are also cases of the existence of a nevus or mole in the iris that in people with light eyes can cause the perception that they have eyes of a different color.
One of the best known cases is that of the British singer David Bowie, whose right eye is blue in color and the left is perceived as black. This ocular peculiarity of the artist is due to a trauma suffered in adolescence that damaged the muscle that contracts the iris of his left eye and as a result left his pupil permanently dilated.