Like most human traits, blue eyes are determined by genes, and no two people have exactly the same hue. It works a lot like individual fingerprints, making our eyes two of the most distinctive parts ...

This means that the odds of having both red hair and blue eyes are around 0.17%, Mark Elgar, Ph.D., an evolutionary biology professor at the University of Melbourne, said in 2018.

Babies are often born blue-eyed, only to end up with eyes that are brown or hazel. Life's Little Mysteries asks an ophthalmologist why.

Here are three facts about this unique hair color. World Redhead Day is celebrated on May 26 each year. People with red hair produce more vitamin D and are less likely to have blue eyes.