Like most human traits, blue eyes are determined by genes, and no two people have exactly the same hue. It works a lot like ...

Blue eyes are caused by a gene mutation ... The mutation was found on an entirely different gene called HERC2. HERC2 turns off OCA2, meaning it turns off the brown and reveals the blue.

The animal's eyes change from a golden colour to a deep blue as summer fades to winter, helping it to see in dramatically different light levels. The part that changes colour is called the tapetum ...

Green light is in the middle. Our eyes only detect three colours: red, green and blue. By combining these we can perceive many different colours Our eyes only detect three colours: red ...