Flashback...or is it Flashforward?

During chapter three especially in the earlier pages of it, I noticed many scene changes from one time period to another. These events seemed to be a sort of flashback where he remembered events. All of these occurrences happened when he slept. When he falls asleep he would switch time periods and events. For example when he and Weary were brought in as prisoners of war he fell asleep and "traveled in time, opened his eyes, found himself staring into the glass eyes of a jade green mechanical owl"(56). It is explained that he is in his optometry office with a patient. After awhile "Billy closed his eyes. When he opened them he was back in World War Two again"(58). This method Vonnegut uses to give the reader background on the character is ingenious. He uses the character's dreams to explain how he lives. I'm not sure these would be quite considered flashbacks since they occur in the future. But in this context they do, as all these events occurred before Vonnegut wrote the book. I'm sure I will see plenty more of these clever scenes as I continue reading.