I've been taking melatonin on and off for sleep...usually it was about 1mg every third day of the week. Recently I miscalculated and took 15 mg. (The tablets I bought at my local store come in a different measurement, so I was a bit confused).
Needless to say, I started experiencing the sensation of dream while I was falling asleep. It's hard to explain. Almost as though I was watching a tv show or movie, but I was staring at my ceiling. I could not see anything such as people or shapes. My vision was slightly blurred, without my glasses my eyes aren't seeing beyond a foot or so. I had audio interruptions in my thought to the point where it was distracting though. At first I had thought my roommate was roaming the halls or it was sounds from the neighboring apartment...when I finally fell asleep the sound became more vivid and the dream took over to match what I was hearing. It was probably the most life-like dream I've ever had.