Eye color varies from person to person and can define a lot when it comes to someone's looks. While we see many different shades of eye color, it's interesting to note that there are just two pigments determining the eventual outcome: brown and red.
How does the Eye Color chart work?
The eye color chart was developed by Carleton Coon using the Martin scale. It helps to classify the eye colors using six categories.
- Amber
A pigment known as lipochrome, which is also found in green eyes, is believed to responsible for amber eye color. Eyes with a predominant yellowish/golden mixed with copper tint are said to be amber in appearance. Amber eyes may appear similar to hazel eyes at first glance but they are distinctly different. This is due to the presence of other colors like brown and orange in hazel.
- Blue
There's no blue pigmentation that is present in blue colored eyes either in the iris or the surrounding fluid. The epithelium of the iris is actually brownish black similar to that seen in brown eyes. Unlike brown eyes, though, the stroma of the iris has very low concentrations of melanin and is much lighter in color. As a result, the longer wavelengths of light are absorbed while shorter wavelengths are reflected exhibiting a blue color.
- Gray
Gray appears on the eye color chart for very similar reasons to blue. The epithelium of the iris is dark colored thanks to the presence of melanin and the stroma is quite clear. Eyes that appear gray, though, have higher deposits of collagen than blue ones. Researchers believe that the scattering of the light on collagen fibers results in the reflected grayish color.
- Brown
The presence of a high concentration of melanin in both the iris epithelium and the stroma is the reason behind the appearance of a brown eye. Both long and short wavelengths of light are absorbed. Dark brown is the predominant eye color around the world and in many parts the only one present.
- Hazel
The appearance of hazel colored eyes is due to the combination of scattering of light and a moderate amount of melanin pigmentation in the anterior border of the iris. As mentioned earlier, hazel is often mistaken with amber on the eye color chart. Under certain changes of light, hazel eyes can shift in appearance towards brown or green.
- Red and violet
Albinism is a condition in which the body's melanin production is severely compromised. The eyes of people suffering from this disorder may appear red or violet under certain lighting conditions. The lack of melanin pigmentation in their eyes allows blood vessels to show through.
Facts About Eye Color
Predictable eye color
With all this information, it's possible to predict with a reasonable degree of accuracy the color of your baby's eye through the use of a baby eye color chart.
The color of the child's eyes can be completely different from either of the parents, although, if both parents have brown eyes, then it's most likely that the child will have brown eyes as well.
In cases where the parents have different eye colors, the darker colors are likely to dominate. That means that brown is more likely to win over blue, green, and almost any other color.
The color of the eye also changes with age as melanin is produced in the body. A lot of children are born with blue eyes that darken to brown as they age.
Overall, the colors of the parents' eyes can help predict the color of the baby's eyes but genetics and natural variation can sometimes throw up surprises as well.
Your eye color and your health
The color of your eyes can indicate the presence of an underlying disorder in the body.
- Wilson's disease
A mutation in the gene coding for the enzyme ATPase 7B prevents the entry of copper from the liver entering the Golgi apparatus in the cells. The copper starts to accumulate in different organs and tissues of the body, including the iris. The appearance is that of a dark brown ring at the periphery of the iris. These rings are also called Kayser-Fleischer rings.
- The coloration of the sclera
The sclera is also called the 'white of the eye'. It is the part that surrounds the iris. A change in the color of the sclera can be a symptom of an underlying disease. Yellowing of the sclera is seen in liver conditions such as jaundice, hepatitis, or cirrhosis. A bluish coloration could indicate the lack of oxygen in the body. Any sudden change in the sclera color should be examined by a doctor.
- Heterochromia
The term heterochromia refers to an eye condition in which the color of the iris varies from one eye to the other or even from one part of the iris to another within the same eye. The condition is quite uncommon and is caused by a lack of an even melanin distribution. The reason behind this could either be genetic, environmental, or due to an injury. The possibility of heterochromia being caused by an in-utero viral infection is being investigated. Some common conditions associated with this appearance includes chimerism, Waardenburg syndrome, and Horner's syndrome.
- Ocular albinism and its relation to eye color
The color of the eyes is determined to a large degree by the melanin pigmentation in different parts of the eye. In people that are suffering from mild albinism, the color of the eye is usually blue due to a lack of melanin in the front of the iris. In severe cases, though, the melanin pigment is absent from the back of the iris. The only reflection is that of a reddish or bright pink color due to the blood passing through the capillaries.
The Final Words
Eye color is not something we choose, it's something we are born with. The use of colored eye lenses allows you control over your eye color and can make you more attractive. It's very interesting to see how a combination of just a couple of pigments and the reflection of light can result in a wide spectrum of eye colors. The eye color chart helps categorize different eye colors. It must be remembered that eye color or a change in the eye color can help diagnose an underlying medical condition.