not believe eyes
not believe one's eyes
Fig. not to believe what one is seeing; to be shocked or dumbfounded at what one is seeing. I walked into the room and I couldn't believe my eyes. All the furniture had been stolen! When Jimmy opened his birthday present, he could hardly believe his eyes. Just what he wanted!
not believe your (own) eyes
to think that something you see is not likely to be real She looked so different in a uniform, I couldn't believe my eyes.
Usage notes: sometimes scarcely or hardly are used instead of not: When he found the ring in the grass, he could scarcely believe his eyes.