Do our Pupils change size Automatically?

Added: 2026-05-28

[00:00:00]Do our pupils change size automatically?

[00:00:02]Yes, our pupils change size automatically without any conscious control. The pupil is the black circular opening in the center of the eye that controls how much light enters.

[00:00:14]Pupillary reflex is responsible for this process. In bright light, the pupil becomes smaller to protect the eye from too much light. In dim light, it becomes larger to allow more light in so we can see better.

[00:00:27]This adjustment happens in less than a second. It is controlled by the brain and muscles in the iris. Pupil size can also change due to emotions like fear, excitement, or concentration, and due to certain medicines. Its main role is to balance light entering the eye for clear vision. So pupils work in the background to help us see in different lighting conditions.