Iv never had visiual hallucinations, but i have had EXTREME audio hallucinations when i first started smoking herb. Im lucky because for the first year of my smoking career i never paid for one bud. I always snatched some from the folks, and it was sooo potent that high status dealers were buying there personal sacks from me, at the time a scrayney little ninth grader(unfortunatly for that too happen i was jacked first by a big time dealer who then smoked all the weed with other big time dealrs, after that my name was synonimus with super high quality herb.so i had to lose some to gain a lot). They were all like DAMN where the fuck do you get your weed from? I wouldnt tell em of course for obvious reasons. Another kid who i knew whos parents smoked bragged about that shit and got his house jacked. I would smoke alot and sit in the dark with my lava lamp and hear full on concerts when there was absoutly no music playing. Not like i would sing these tunes inmy head, but i would sound like i was blasting my sterio! And for some reason it would always start of with Metallicas Harvester of Sorrow, which was strange because iv never really liked metallica all that much.