5 Fascinating Facts About Eye Colour
Have you ever wondered why your eyes are the colour they are? Eye colour is determined by the amount of melanin in your iris, which is the coloured part of your eye. People with more melanin tend to have brown eyes, while those with less melanin often have blue, green, or hazel eyes. But that’s just the beginning!
Here are five fascinating facts about eye colour that might surprise you.
1. Technically, Everyone Has Brown Eyes
It may sound unbelievable, but every eye contains brown pigment. The difference in eye colour comes down to how much light is absorbed versus reflected by the melanin in the iris.
- Dark brown eyes have a high concentration of melanin, which absorbs most of the light, making the eye appear darker.
- Lighter eyes (blue, green, hazel) have less melanin, allowing more light to scatter and reflect outward, creating the appearance of different colours.
This is similar to how the sky looks blue—the way light interacts with certain particles creates the illusion of different shades!
2. Some People Have Two Different-Coloured Eyes
If you’ve ever met someone with two different eye colours, you’ve seen a condition called heterochromia. This can occur in a few different ways:
- Complete heterochromia: One eye is an entirely different colour than the other.
- Sectoral (partial) heterochromia: A single eye contains two different colours, often forming a distinct patch or ring.
- Central heterochromia: A person has a different colour in the center of the iris that radiates outward.
While some people are born with heterochromia, others may develop it later due to injury, medication, or medical conditions. If one of your eyes changes colour suddenly, it’s important to see an optometrist, as it could be a sign of an underlying eye condition such as glaucoma or inflammation.
3. All Blue-Eyed People Share a Common Ancestor
If you have blue eyes, you share something in common with millions of people around the world—a single ancestor from thousands of years ago!
A study from the University of Copenhagen found that every person with blue eyes can trace their lineage back to one individual who lived between 6,000 and 10,000 years ago. This person had a genetic mutation that reduced the amount of melanin in their iris, leading to the first instance of blue eyes.
Over time, this gene was passed down through generations, spreading across Europe and other parts of the world.
4. Eye Colour Affects Your Sensitivity to Light
Have you ever noticed that some people squint more in bright sunlight? The amount of melanin in your eyes affects how well they block out UV rays and harsh light.
- Light-coloured eyes (blue, green, hazel): Less melanin means more light passes through, making these eyes more sensitive to glare and bright environments.
- Dark brown eyes: Higher melanin levels act like built-in sunglasses, absorbing more light and offering greater natural protection from UV rays.
Regardless of your eye colour, always wear sunglasses when outdoors to shield your eyes from UV damage.
5. Predicting a Baby’s Eye Colour Isn’t as Simple as You Think
Many people believe that a baby’s eye colour is easy to predict based on their parents’ eyes, but it’s more complicated than that.
- Eye colour isn’t controlled by a single gene—it’s influenced by up to 16 different genes!
- While brown eyes are more common, it’s possible for two brown-eyed parents to have a blue-eyed child if they carry recessive genes for lighter eye colours.
- Many newborns are born with blue or gray eyes because their irises haven’t developed enough melanin yet. Their true eye colour usually settles in within the first year of life.
No Matter the Colour, Your Eyes Deserve the Best Care
Whether your eyes are deep brown, icy blue, or vibrant green, taking care of them is essential for long-term vision health.
At Optometrists’ Clinic, we offer comprehensive eye exams for all ages, helping you keep your vision sharp and your eyes healthy. If you’re due for a checkup or looking for quality eyewear or contact lenses, visit one of our locations in the Edmonton area.
Book your eye exam today and ensure your eyes stay in top shape for years to come!
