Brown is the most common eye color worldwide by a large majority. In contrast, green is one of the rarest eye colors worldwide. The color of the eyes depends on how much melanin the eyes contain.

They appeared in an evolutionary blink and changed the rules of life for ever. Before eyes, life was gentler and tamer, dominated by sluggish soft-bodied creatures lolling around in the sea. The ...

Life probably first appeared ~3.7 billion years ago as a simple cell with the ability to replicate. Current extant cyanobacteria represent an early form, or more likely they are a direct descendent, ...

The human eye is an exquisitely complicated organ. It acts like a camera to collect and focus light and convert it into an electrical signal that the brain translates into images. But instead of ...