My boyfriend has tripped on LSD a couple of times over the past seven eight years without too much of a lasting consequence. However, a friend of mine suffered severe behavioral/brain damage recently after a single acid trip. He still states that he can see certain things move which to us appear very stationary. He even sees different colors where there's clearly only one. My boyfriend enters into strange complicated debates about reality and human capacity every time I try to tell him that LSD might damage his normal senses. What exactly does LSD do to the body? Does it actually cause neural or cellular alterations?