what does the pupil do

The pupil is the circular opening located in the center of the iris of the eye. It controls the amount of light that enters the eye. The size of the pupil is controlled by muscles within the iris, with one muscle constricting the pupil opening to make it smaller and another muscle dilating the pupil to make it larger. The pupil gets bigger or smaller in response to changes in light, and it plays a crucial role in regulating the amount of light that enters the eye to facilitate vision. In bright light, the pupil constricts and gets smaller, while in dim light, the pupil dilates and gets bigger. Additionally, the pupil also plays a role in the accommodative pupillary response, which involves both pupils constricting when focusing on a near object. Overall, the pupil is an essential component of the vision system, regulating the amount of light that enters the eye to facilitate clear vision in various lighting conditions.