All eyes change color

Eye color: development and change

From All About Vision

  1. How the eye color develops
  2. Changes in eye color

Eye color is the genetic trait that often fascinates parents most in their child's development. Will his eyes be black, brown, blue, gray, green, or hazel? Or will it be a combination of all these colors?

What a child looks like depends on the genes each parent contributes to the child. They can mix and match in many different ways. The influence of a parent's genes can only be seen after birth.

How the eye color develops

The colored part of the eye is called the iris. Your pigmentation determines our eye color.

The human eye color has its origin in three genes, two of which are well known. These genes are responsible for the most common colors - green, brown, and blue. Other colors such as gray, hazelnut brown and multiple combinations have not yet been fully researched and explained.

In the past, the eye color brown was seen as a “dominant” characteristic and the blue eye color as a “recessive” characteristic. But modern science has shown that eye color is not that easily explained.

Because it doesn't just come from the parents' eye colors, as if two colors were mixed together. Each parent has two pairs of genes on each chromosome, and there are several ways that this genetic information is reflected in eye color.

And eye color can change early in life.

Most Caucasian babies are born with blue eyes, which can get darker during the first three years of life. Darkening occurs when melanin develops as you age. This brown pigment is usually absent right after birth.

Children can have completely different eye colors than their parents. But if both parents have brown eyes, it is very likely that their children's eyes will also turn brown.

Darker colors tend to dominate - that is why brown gains the upper hand over green and green over blue.

However, if one parent has brown eyes and the other has blue eyes, this does not automatically lead to a child with brown eyes.

Some children are born with irides that are mismatched in color. As a rule, so-called heterochromia is caused by impaired pigment transport during development, local trauma in the uterus or shortly after birth, or a benign genetic disorder.

Other causes can include inflammation, freckles (diffuse nevus) on the iris, and Horner's syndrome.

If you notice anything unusual about your eye color, see your ophthalmologist or optometrist immediately.

ARE YOU CONCERNED ABOUT YOUR EYE COLOR OR EYES? Find an optician in your area and make an appointment.

Changes in eye color

The iris is a muscle that expands and contracts to regulate the size of the pupil. The pupil enlarges when the lighting is subdued and becomes smaller when the lighting is brighter. Also, when you focus on nearby objects - for example, the book you are reading - your pupil will get smaller.

When the pupil size changes, the pigments in the iris compress or spread, changing the color of the eyes a little.

In addition, certain emotions can change both the size of the pupils and the color of the iris. This is why some people say that their eyes change color when they are angry or in love.

Eye color can also change with age. This happens in 10 to 15 percent of the Caucasian population, and therefore in people who are generally lighter in color. For example, hazel eyes actually get darker with age.

If your eye color changes significantly in adulthood, or if one eye changes from brown to green or from blue to brown, it is important to see your ophthalmologist or optometrist.

Changes in eye color can be a warning sign of certain diseases, such as: B. for the Fuchs heterochromic iridocyclitis, the Horner syndrome or the glaucoma.

ARE YOU CONCERNED ABOUT YOUR EYE COLOR OR EYES? You can find an optician in your area here.

Page published in September 2020

Page updated in May 2021