An eyelash is one of the short, curved hairs that grows along the edge of your eyelid. Each eye has dozens of these tiny hairs forming a protective fringe. They might seem decorative, but they serve an important purpose: keeping dust, dirt, and small particles out of your eyes. When something gets too close, your eyelashes sense it and help trigger your eyelids to blink automatically.

Eyelashes grow, fall out, and regrow naturally throughout your life, just like the hair on your head but much faster. A single eyelash typically lasts only a few months before falling out and being replaced. You probably don't notice when you lose one because new ones are always growing in.

The word can also describe something that happens by the narrowest margin. If you win a race by an eyelash, you barely won at all.