Question

you are the apple of my eye是啥意思

Answer 1

"apple of one's eye" 这一词最早出现於圣经：
诗篇17:8：Keep me as the apple of the eye, hide me under the shadow of thy wings. 
《申命记》三十三章的第十节：In a desert land he found him, in a barren and howling waste. He shielded him and cared for him; he guarded him as the apple of his eye. 

跟东方一样，在西方人们一直都把苹果视为一种吉祥的水果。不是还有另一句英文谚语："An apple a day, keeps doctor away"。 
"apple of one's eye"就是指「珍贵的东西」，也就常被引申为「珍爱的人或物」。 
所以说You are the apple of my eye，意思就是指：你是我的挚爱、你是我的唯一 

另外《那些年，我们一起追的女孩》，英语：You Are the Apple of My Eye。