PERRLA is an acronym used to document a common pupillary response test. It helps eye doctors remember what to check for when examining your pupils. Your eyes, besides allowing you to see the world, ...

The black circle in the center of your eye is your pupil. It changes size thousands of times a day. When you're in dim light, it gets bigger to let more light in. When you're in bright light, it ...

You look in the mirror and notice that the dark circles in the middle of your eyes are bigger than usual. What's going on? Those dark circles are your pupils, the openings that let light enter your ...