Hallucinogen Persisting Perception Disorder or HPPD is a psychological disorder characterized by a continual presence of visual disturbances that are reminiscent of those generated by the ingestion of hallucinogenic substances. Previous use of hallucinogens is a necessary, though not sufficient, cause for the disorder. HPPD is distinct from flashbacks by reason of its relative permanence; whereas the latter is transient, the effects of HPPD occur for a prolonged or indefinite period.
There are an array of perceptual changes that accompany HPPD. Dr. Henry David Abraham was the first to formally document the more quintessential features of the disorder. These include the following visual abnormalities: halos surrounding objects, trails following objects in motion, difficulty distinguishing between colors, apparent shifts in the hue of a given item, the illusion of movement in a static setting, air assuming a grainy or textured quality (visual snow or static, by popular description), distortions in the dimensions of a perceived object, and a heightened awareness of floaters. The visual alterations experienced by those with HPPD are not homogeneous; discrepancies may be evident in both the number of the preceding symptoms encountered and their respective intensity.
(from wiki)
OMG – I wondered why I still get traces or every now and then the carpet/curtain moves. Holy crap – :yakk:
