can't believe one's eyesAn idiomatic expression used when something is so surprising or incredible that one can hardly believe what one is seeing. In conjugated sentences, the pronoun and possessive adjective change to match the subject, as in « je n'en crois pas mes yeux » (I can't believe my eyes).
FR: Il est difficile de ne pas en croire ses yeux devant un spectacle pareil.
EN: It's hard not to believe one's eyes when faced with a spectacle like that.