Question

"they could not believe their eyes .it's not possible they said "they said
who said this to whom ?​

Answer 1

Answer:

Origin

There doesn’t seem to be any history available for this phrase, but it is more to do with seeing or hearing something surprising or shocking than the fact that your vision is poor, or that you are deaf.

The origin of the phrase is based on the fact that you can’t believe your eyes or ears because what you saw or heard is either a pure fantasy or an astonishing scene.

Source: theidioms.com