The phrase "apple of eye" refers to a beloved person or thing that is cherished above all else. There are many synonyms or similar phrases that convey this sentiment, such as "darling," "precious," "treasured," "dearest," "beloved," "pet," "favorite," "prized possession," and "heart's desire." Each of these alternatives carries a similar connotation of deep affection, adoration, and significance. Whether referring to a person, animal, or object, "apple of eye" and its synonyms are all powerful expressions of love and appreciation.