Prosopometamorphopsia: a condition where people see  'demonic' face distortions

Imagine if every time you saw a face, it appeared distorted. Well, for those who have a very rare condition known as prosopometamorphopsia (PMO), which causes facial features to appear distorted, that is reality.

Prosopometamorphopsia explains, "Prosopo comes from the Greek word for face 'prosopon' while 'metamorphopsia' refers to perceptual distortions.  Specific symptoms vary from case to case and can affect the shape, size, color, and position of facial features. The duration of PMO also varies; it "can last for days, weeks, or even years.

A new Dartmouth study published in the "Clinical Pictures" section of The Lancet reports on a unique case of a patient with PMO. The research is the first to provide accurate and photorealistic visualizations of the facial distortions experienced by an individual with PMO.

The patient, a 58-year-old male with PMO, sees faces without any distortions when they are viewed on a screen and on paper, but he sees distorted faces that appear "demonic" when viewed in-person. Most PMO cases however, see distortions in all contexts, so his case is especially rare and presented a unique opportunity to accurately depict his distortions.

Scientists have heard from multiple people with PMO that they have been diagnosed by psychiatrists as having schizophrenia and put on anti-psychotics, when their condition is a problem with the visual system,  according to the researchers.

And it's not uncommon for people who have PMO to not tell others about their problem with face perception because they fear others will think the distortions are a sign of a psychiatric disorder.

"It's a problem that people often don't understand."

Through their paper, the researchers hope to increase public awareness of what PMO is.

Computer-generated images of the distortions of a male face (top) and female face (bottom), as perceived by the patient in the study. Credit: Images provided by A. Mello et al.

Visualising facial distortions in prosopometamorphopsia, The Lancet (2024). www.thelancet.com/journals/lan … (24)00136-3/fulltext