Pinkeye is only a descriptive term. It’s what happens when the transparent membrane over the eye (called the conjunctiva) gets inflamed. The blood vessels inside it swell and become visible, giving the eye a pink or red appearance. The causes of pinkeye (officially known as conjunctivitis) vary with age. Young children often develop it from a viral or simple bacterial infection, and in these cases, the symptoms almost always resolve on their own. The American Academy of Pediatrics recommends that no child be excluded from school or child care because of pinkeye, but not every school follows this advice. That’s why pediatricians often prescribe antibiotic drops even if the infection might be caused by a virus.

Pinkeye that returns frequently could be a sign of allergies or a more chronic condition, so if it keeps coming back, see your pediatrician or an eye doctor. Also seek care immediately for pinkeye that comes with altered vision, a foreign body sensation, or pain with light.