pupil
[C] Countable
pl: pupils
The term evokes a traditional, hierarchical relationship between a master and a student. While student is a broad term for anyone enrolled in a course, pupil suggests a more intimate or guided form of instruction, often associated with primary education or a specific apprenticeship. It carries a sense of molding and direct mentorship. In the anatomical sense, the word describes a void rather than a physical structure. It is the gateway of the eye, and its movement is a biological response to environment and emotion, creating a visual link between the inner mind and the outer world.
Countable whether referring to a student in a classroom or the physical openings in both eyes.