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 …

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.

Dec 29, 2025 · 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 …

The meaning of PUPIL is a child or young person in school or in the charge of a tutor or instructor : student.

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 …

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 …

pupil noun [C] (EYE PART) the circular, black area in the center of the eye that gets larger and smaller and lets in light (Definition of pupil from the Cambridge Academic Content Dictionary © …

Oct 30, 2023 · Structure of the eyeball seen in a transverse section. The pupil is the small black circle located in the center of the eyeball. Surrounding the pupil is the colored part of the eye, …

PUPIL definition: the expanding and contracting opening in the iris of the eye, through which light passes to the retina. See examples of pupil used in a sentence.

pupil, in the anatomy of the eye, the black centre opening within the iris through which light passes before reaching the lens and being focused onto the retina.