Visual condition

Hallucinogen persisting perception disorder (HPPD)

Long-lasting visual disturbances that continue after the effects of a hallucinogenic drug should have worn off — sometimes for years.

Try Hallucinogen persisting perception disorder (HPPD) in the simulator →

What it looks like

HPPD presents as a constellation of persistent visual symptoms: TV-like static (visual snow), trails behind moving objects, halos around lights, walls and patterns that appear to "breathe" or shimmer, increased floaters, geometric grids overlaid on surfaces, and intensified responses to bright lights and patterns. Symptoms can be present every day for months or years and are usually distressing.

How it differs from other vision issues

Unlike a brief drug trip, HPPD persists when the person is sober. Unlike visual snow syndrome (which is similar), HPPD has a clear onset after hallucinogenic drug use (often LSD, psilocybin, MDMA, or DMT). Anxiety and depression are common comorbidities.

Two types (DSM)

HPPD Type I: brief, occasional flashbacks. HPPD Type II: chronic, continuous disturbances — what most patients describe as "the world hasn't looked normal since." This simulator is configured for Type II.

When to see a doctor

See a psychiatrist or neurologist if symptoms persist for weeks after drug use. There are no FDA-approved treatments specifically for HPPD, but some medications and behavioral approaches help. Acute new visual symptoms after recent drug use can sometimes signal something more serious and warrant prompt evaluation.

Also known as

HPPD · Flashbacks · Persistent psychedelic perception

VisualSim is a communication tool — it helps you show your doctor what you see. It is not a diagnostic tool and is not a substitute for medical advice, examination, or treatment. If you are experiencing sudden flashes of light, new floaters, sudden vision loss, severe headache, or one-sided weakness or numbness, seek medical attention immediately.

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