The iris is a structure behind the transparent cornea of the eye. It has a circular opening called the pupil that changes size in response to the light level. Your pupils are usually the same size as ...

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.

Leukocoria means "white pupil." It describes a condition where the pupil of the eye is white rather than black. It is more common in children but can occur in adults as well. Many different conditions ...

Medications, trauma, and medical conditions can cause miosis or constricted pupils. Seek emergency help if you experience signs of a stroke, like confusion or trouble speaking. A healthcare provider ...