Bible Dictionaries
Apple of the Eye
Holman Bible Dictionary
 An English expression that refers to the pupil of the eye and therefore to something very precious. Three different Hebrew words or phrases are rendered as the apple of the eye: (1) the word in Deuteronomy 32:10 and  Proverbs 7:2 literally means “little man” and evidently refers to the reflection of a person in the eye of another; (2) the word in  Psalm 17:8 and  Lamentations 2:18 (KJV) literally means “the daughter of the eye” with possibly the same significance as (1); and (3) the word in  Zechariah 2:8 literally means “gate.” The reference in  Lamentations 2:18 is to the pupil of the eye as the source of tears; the other references are metaphorical of something that is precious.  
Copyright Statement
These dictionary topics are from the Holman Bible Dictionary, published by Broadman & Holman, 1991. All rights reserved.  Used by permission of Broadman & Holman.
Bibliography Information
Butler, Trent C. Editor. Entry for 'Apple of the Eye'. Holman Bible Dictionary. https://www.studylight.org/​dictionaries/​eng/​hbd/​a/apple-of-the-eye.html. 1991.