Zizek in the perverts guide had a bit about this scene and I bet you can find it easily - it's where we get "eating from the trashcan of ideology" because the one guy tells the other that he's either gonna put the glasses on or he's gonna eat the trashcan. I can't remember if it's in the perverts guide or not, but that feeling of encountering bare reality without ideology is... intense, unpleasant and so on.