The two English words pupil are related to each other, and to poppet, puppet, and pupa, through their Latin root, pupa ‘girl, doll’. Pupil entered English via Old French from the Latin forms pupillus (diminutive of pupus ‘boy’) and pupilla (diminutive of pupa ‘girl’); it originally meant ‘orphan or ward’, and did not take on its modern meaning until the 16th century. Pupil meaning ‘the centre of the eye’ is from the feminine form pupilla (literally ‘little doll’ or ‘young girl’): it acquired its English meaning from the phenomenon whereby one can see a tiny reflected image of oneself in another person's eyes.

ME: from OFr. pupille or L. pupilla, dimin. of pupa ‘doll’ (from the tiny reflected images visible in the eye).