The opening in the colored iris of the eye. It appears black because behind the pupil is the dark interior of the eye. The pupil changes in size as the iris adjusts to existing light conditions. Light enters the clear cornea, passes through the pupil and into the eye’s lens.

The Hebrew word ʼi·shohnʹ (De 32:10; Pr 7:2), when used with ʽaʹyin (eye), literally means “little man of the eye”; similarly, bath (daughter) is used at Lamentations 2:18 with the idea “daughter of the eye,” both expressions referring to the pupil. The two are combined for emphasis at Psalm 17:8 (ʼi·shohnʹ bath-ʽaʹyin), literally, “little man, daughter of the eye” (“pupil of the eyeball,” NW). The reference is evidently to the tiny image of oneself that can be seen reflected in that part of another’s eye.

The eye is extremely tender and sensitive; even a small hair or speck of dust between the lid and eyeball is quickly noticed. The transparent part of the eye (the cornea) covering the pupil must be guarded and cared for, because if this portion is scarred by injury or becomes cloudy through disease, distorted vision or blindness can result. With force and yet with delicacy of expression the Bible uses “the pupil of your eyes” in speaking of that which is to be guarded with utmost care. God’s  law is to be so treated. (Pr 7:2) Mentioning God’s fatherly care of Israel, Deuteronomy 32:10 says that He safeguarded the nation “as the pupil of his eye.” David prayed that he would be protected and cared for by God as “the pupil of the eyeball.” (Ps 17:8) He wanted Jehovah to be quick to act in his behalf when under enemy attack. (Compare Zec 2:8; where the Hebrew ba·vathʹ ʽaʹyin, “eyeball,” is used.)​—See EYE.

Disciple. “Pupil” also means one who learns or takes instruction, a disciple. Thus some Bible versions use it to render the Greek ma·the·tesʹ, as at Luke 6:40 (NE, TEV, NW, AT). On this meaning, see DISCIPLE.