The pupil is the opening located in the center of the iris of the eye.
Thepupil sizeis controlled by muscles of theiristhat narrow and widen the opening.
Anatomy and Function of Pupils
The pupil controls how much light enters the eye.
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The pupil refers specifically to the opening in the center of the iris.
Variation in Size
There is a wide variation in pupil size from one person to the next.
Certain medications and conditions like cluster headaches can also lead to an abnormal pupillary response.
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