It's a condition described as a living hell by sufferers, and it's marked by stigma and shame. Hallucinogenic persistent perception disorder, or HPPD, results in disturbed vision where the sufferer constantly sees visual snow, halos, and trails. It's triggered by the use of psycho-active drugs and for some people it can cause extreme anxiety and suicidal thoughts. With illegal drug use on the rise and the emergence of micro dosing to treat mental illness there are calls for more research into the condition.
