In optical terms, the anatomical pupil is the eye's aperture and the iris is the aperture stop. The image of the pupil as seen from outside the eye is the entrance pupil, which does not exactly correspond to …

Mar 21, 2026 · The amount of light entering the eye is restricted by the aperture in the iris, the pupil. In a dark room, a person’s pupils are large, perhaps 8 mm (0.3 inch) or more in diameter.

Oct 4, 2022 · The pupil of your eye, the black hole in your iris, works with the lens to send light to the retina, where it becomes electrical signals sent on to the brain through the optic nerve.

Jan 6, 2026 · 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.

Dec 4, 2024 · Pupils are the dark-colored openings at the center of your eyes that let light in. Doctors can look at your pupils for clues about your health. The size of your pupils and how they react to...

Apr 20, 2022 · All the different part of your eyes work together to help you see. Learn the jobs of the cornea, pupil, lens, retina, and optic nerve and how they work together.

: the usually round opening in the iris that contracts and expands to control the amount of light entering the eye.

Feb 26, 2019 · The pupil is the opening in the center of the iris (the structure that gives our eyes their color). The function of the pupil is to allow light to enter the eye so it can be focused on the retina to …

n. The apparently black circular opening in the center of the iris of the eye, through which light passes to the retina. [Middle English, from Old French pupille, from Latin pūpilla, little doll, pupil of the eye …

The round opening in the center of the iris (the colored tissue that makes the "eye color" at the front of the eye). The pupil changes size to let light into the eye.