i remember this from when i was a kid, sorry if all knows it....
a fellow had this glass eye, and he used to go around showing off, by popping it out of it's socket into the air, then catching it into the open socket....then one day during a performance, he accidentally swallowed it........he figured he'll just wait till it went through his system.....but days went by and nothing ....it was stuck somewhere...........so he decided to go to the doctor, who then asked him to drop his trousers....but when the doc bent down to check his rear end, he saw this eye ball staring at him....so he looked up at the fellow, and said....what's wrong?.... don't you trust me??