Here are seven reasons your pupils may be dilated, and when you should see a doctor. 1. Light Your pupils help you see by controlling how much light enters your eye. To do this, they react to the ...

A contracted pupil during sleep may be an indication the brain is replaying new memories while a dilated one may hint at older memories being relived, a new study suggests. The study, published in ...

Each portrait was manipulated to display either constricted or dilated pupils while keeping iris brightness constant. Participants were asked to rate the primates on cuteness, friendliness ...