Have you ever noticed that the musician David Bowie has two different colored eyes? Today, many people love to use colored contacts to change their overall appearance, but it is unusual to see a person with two different colored eyes. Although animals, like cats, seem to have this characteristic more than humans, the reasons behind eye color difference is not always genetic. To get a better idea how this unique visual feature comes about, take a look at these pieces of ophthalmological trivia.
How genes are expressed in two different ways
Most people have a unique eye color that is mirrored in each eye, so how can this happen differently? Science calls this unique form of genetic expression “mosaicism.” This means that two different genotypes are developed in a single egg when it is fertilized. So instead of having one gene for eye color, people have two. For instance, they may have one blue eye and one green eye.
The reason for calico cats
Cats often have two different colored eyes, and this is more common in females. The reasons mosaicism occur are gene mutations, chromosomal mutations, unusual cell division in mitosis, and X-inactivation that sometimes happens in female mammals. In particular, deactivating one of the two X chromosomes in female cats results in the calico fur markings. This is why calico cats are always female. Calico females may also have two different colored eyes due to having a predisposition for mosaicism.
The real reason David Bowie has two different colored eyes
Genetics aside, there is a reason that the eye color can change and it is due to an injury. While people can be born with two different colored eyes as a gene expression, David Bowie had an injury to his eye that caused it to start looking different. In particular, David Bowie had an injury to one pupil that caused it to become permanently dilated.
Prevent permanent eye color changes due to injury
When you have a problem with your eyes, it can be easy to be dismissive of the problem. However, in some cases, injuries to the eyes can be treated to prevent permanent damage like eye color changes. To get the sound advice you need for your vision and eye health, contact us today. We are always happy to help you with any questions you have, and we look forward to seeing you at one of The Vision Centers locations.