HPPD: Hallucinogen persisting perception disorder https://en.wikipedia.org/wiki/Hallucinogen_persisting_perception_disorder https://en.wikipedia.org/wiki/Halluc

HPPD: Hallucinogen persisting perception disorder https://en.wikipedia.org/wiki/Hallucinogen_persisting_perception_disorder https://en.wikipedia.org/wiki/Hallucinogen_persisting_percep... Total tangent here, but in my opinion, most HPPD are optical/perceptual defects that everyone experiences all the time, but normally our minds block, filter, or compensate for. Taking psychedelics makes people aware of these defects, and once you notice them, you can't "unsee" them. My personal experience with this is that very mild astigmatism causes diffracted halos around light sources. I never noticed these until taking psychedelics. Now I always notice them, but they're certainly caused by defects in my eyes' lenses and not by some permanent direct effect of psychedelics. Similar with floaters, visual snow, POV effects and so on. Many of these effects/defects become exaggerated whilst tripping and hence get noticed, then when people sober up and still notice them, they think it's something new, rather than realizing it's something that's been going on unnoticed the whole time.