A basic feature of man is his eye color. Whether brown, blue or green - this is also shown in the passport. But why do people actually have different eye colors?
Iris and pupil The iris or iris is the colored part of the eye and is a kind of iris for the eye. It controls the incidence of light: in the case of brightness, it narrows - the incidence of light is thus reduced. The iris acts like the aperture of a camera. The activity of these muscles is controlled by nerves and happens unconsciously to humans. The pupil is the opening in the iris that lets the light into the eye. At high brightness, the pupil is the smallest (1.2mm) and the largest in the dark (9mm).
How does the color of the eyes come about? The pigment melanin, which also determines the tint of skin and hair, is responsible for the eye color. Depending on how much pigment is embedded in the cells, the eyes also get their individual color. High melanin concentration results in brown eyes; These people usually have a darker skin than others. Conversely, you rarely see anyone with dark hair and blue eyes. A lower pigment content makes the iris - depending on dosage - appear green, blue or gray. The less melanin, the more blue eyes a person has.
As a baby, we usually have blue eyes ... The final color is genetically predetermined. In the womb, the iris is still light blue and only later reaches its full color. The reason: the pigment develops only in the first years of life in the body. That means: with increasing age also the eye color changes.
Eye color - an invariable feature If this process has then come to a standstill, our eye color is always the same. So, if you have brown eyes, you can not get blue ones, and blue-eyed people have blue eyes all their lives. By the way: If you still want to try a different eye color, you have this option with the so-called iris lenses.