Genes are made of deoxyribonucleic acid (DNA), which contains sequences of four nucleotide bases (adenine, cytosine, guanine, and thymine) that act as biological instructions for making proteins.

Add Popular Science (opens in a new tab) More information Adding us as a Preferred Source in Google by using this link indicates that you would like to see more of our content in Google News results.

Cat-like eyes show up in searches everywhere. If the internet is this obsessed with eye color, how rare are green eyes in humans? They're uncommon enough that seeing them still feels like spotting a ...

Janelle Sventek, O.D., an expert at the University of Alabama at Birmingham, provides insight into the science behind eye color and how families can protect their child’s vision from an early age.

Blue, brown, green, or something in between, the science behind the color of your eyes comes down to pigment and your genes, ...

Gear-obsessed editors choose every product we review. We may earn commission if you buy from a link. Why Trust Us? Here’s what you’ll learn when you read this story: Eye color comes down to a pigment ...