Pupil dilation

Pupil dilation refers to the process where the black center of your eye (the pupil) widens to allow more light in. This happens automatically and is controlled by muscles in the iris, the colored part of the eye, responding to lighting conditions or emotional states. For example, pupils dilate in dim environments to improve vision or in response to excitement or stress. Dilation is also used by doctors to examine the eyes more closely. Overall, pupil size adjusts to help your eyes see better and can reflect your emotional or physical state.