apple (n.)
pupil, centre
LLL V.ii.475[Berowne to Boyet, of the Princess] Do not you ... laugh upon the apple of her eye? [i.e. looking into her eyes]
MND III.ii.104[Oberon to himself, as if to the flower, of Demetrius] Flower of this purple dye ... / Sink in apple of his eye [or: eyeball]
SHAKESPEARE'S WORDS © 2018 DAVID CRYSTAL & BEN CRYSTAL