The claim: An image shows a rare eye condition called 'pupula duplex' A striking image online is catching the eyes of social media users. "The Pupula duplex is a medical oddity that is characterized ...

The pupil controls how much light enters the eye, allowing for clear vision. In low light, pupils widen to let in more light, and in bright light, they narrow to prevent too much light from entering.

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 ...

The size of your pupils varies throughout the day, but most people’s pupils fall within a particular size range. We’ll look at when and why your pupils change size. First, the range of “normal” pupil ...