Glass eye

A day before his proctologic exam, a one eyed man accidentally swallowed his glass eye. He was worried for a while, but there were no ill effects, so he forgot about it.
Once he was in the doctor's office, the man followed instructions, undressed, and bent over. The first thing the proctologist saw when he looked up the man's ass was that eye staring right back at him.
"You know, " said the doctor, "you really have to learn to trust me."