When for no apparentreason guys surprise you by slapping you in the eye with their cock.
I'm setting at my computer and yell "honey get me something to drink" He leaves the room returns with my drink and places it on the desk.I assume he goes back to whatever it was he was doing and all of a sudden from out of nowhere Wham a "Fly-by-cock-in-the-eye.I'm left digging my contact out of my eye socket while he's running through the house giggling in utter triumph.
The phrase is said in the song "Lucy in the Sky with Diamonds" by the Beatles. When looking into a kaleidoscope, it seems as if the world turns into many different colours and swirls and reality doesn't seem real anymore. This is what happens in an LSD or Acid trip. The song is about this happening to Lucy. When someone says a person has kaleidoscope eyes, it means they're 'tripping' (hallucinating) on Acid.
"Did you see *blank*?"
"Ya, he's got kaleidoscope eyes!"