Does Eye Color Affect Sight?

Everyone’s eyes contain a natural chemical called melanin within the iris of the eye. The more melanin that is someone’s eyes, the darker the color will be. The main reason melanin is important is that it’s density can affect visual discomfort, depending upon the situation. Some people have made assumptions that eye color may make a difference on the way people actually see things.

The melanin has an effect on the way light distributes the colors and are reflected or absorbed by the eyes. While eye color doesn’t affect how people see something, the color of someone’s eyes can cause them to have different sight abilities in various lighting conditions. The melanin concentration in the pigment of the iris cells acts as a way to protect the iris from higher sunlight by spreading the light out.

Someone with darker eyes has a higher amount and density of melanin. This means that in bright sunlight, the melanin reflects light inside the eye and they experience less problems with glare from the sun. Melanin acts as a kind of protector, spreading the light rays away from the iris. This does give them better contrast ability in these conditions. An example where darker eye color is an advantage might be in the glare of headlights when driving at night.

People that have less melanin tend to have lighter colored eyes and therefore they lack the protection from the brighter light and can experience more discomfort of glare and less contrast. In sunlight, the risk is that the harmful UV light rays will pass through the irises of those with lighter colored eyes and cause damage through the development of cataracts or a disease called macular degeneration. UV-blocking sunglasses can be worn to reduce these risks.

There have been some scientific studies that suggest that there is a relationship between eye color and reaction time. Those with darker colored eyes did well in things like hitting a tennis ball or boxing. These are called reactive tasks. Whereas those people with lighter colored eyes performed better at golfing or bowling. These are called self-paced tasks.

While the color of someone’s eyes does not directly affect how they see things, the lighting conditions can be a secondary level that can affect sight. No matter what color of eyes, everyone is recommended to wear UV-blocking sunglasses when they are outside in the daylight. All people can experience damage from the UV rays of the sun, with any eye color or shade.


You might want to set up a science project experiment to figure out exactly which eye colors have the best sight abilities. If you have family and friends with different eye colors you could create a test to see how light sensitive they are.