not believe your eyes
US /nɑt bɪˈliːv jʊər aɪz/
UK /nɑt bɪˈliːv jʊər aɪz/
1.
to be so surprised by something that you think you are imagining it
:
•
When I saw the famous actor walking down my street, I could not believe my eyes.
•
She opened the gift and could not believe her eyes; it was exactly what she wanted.