I was nearly frantic trying to find my glasses once. I enlisted the aid of SO (who complied, but was smirking for reasons that would soon become obvious). While I was digging around in places it could have fallen, I mentioned that it would be so much easier if I could actually see clearly while doing this.
Then I had a brainstorm. I took my glasses out of my blouse's front pocket and put them on so I could see more clearly if my glasses had fallen behind the desk...