Small pupils can happen when you’ve had a stroke or when you’ve used opiates, among other reasons. Mydriasis is the name of the opposite condition, having dilated pupils.

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 …

Mar 28, 2019 · There's an average pupil size that's considered normal. Measured in millimeters, your eyes' pupils can change based on light, medications, and even emotions.

PUPIL definition: 1. a person, especially a child at school, who is being taught: 2. someone who is being taught a…. Learn more.

Apr 22, 2025 · The pupil is the opening located in the center of the iris of the eye. It controls the amount of light that enters the eye so that you can see clearly. The pupil size is controlled by …

: a child or young person in school or in the care of a tutor or teacher. : one who has been taught or influenced by a person of fame : disciple. : the usually round opening in the iris that …

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 …

Sep 22, 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 …

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, …

Feb 26, 2019 · Typically, the pupils appear perfectly round, equal in size and black in color. The black color is because light that passes through the pupil is absorbed by the retina and is not …