What Is Prosopometamorphopsia? The “Exceedingly Rare” Condition That Made A Patient See Faces As Dragons

“Prosopometamorphopsia is this exceedingly rarely diagnosed condition,” said neuroscientist Dr Austin Lim to IFLScience. “It essentially causes a person to see other people’s faces progressively transform into other face-like things.” 

Lim wrote about the condition in his new book, Horror On The Brain, which IFLScience explored at our May 2025 CURIOUS Live event. As Lim describes, it’s a rare and curious neurological condition that causes a person to see other faces as distorted. 

It doesn’t necessarily kick in right away. A person with this condition may be looking at a normal face only to watch it morph and transform. It’s particularly puzzling in the respect that the person’s vision can be otherwise normal, and how it can affect how the person perceives a whole face, or just part of it.

A 2020 case study detailed the experience of a patient nicknamed AD. He presented to clinicians complaining that all faces appeared to melt on one side, creating an image that significantly diminished his quality of life. To better understand the strange illness, the researchers showed AD a series of images of faces and other objects on different planes, at different angles, and from different perspectives. The results showed that he was capable of correctly seeing inanimate objects, but faces were almost always distorted, despite being rotated and turned. 

This kind of (PMO) is known as hemi-prosopometamorphopsia, or hemi-PMO. The condition had only ever been recorded 25 times in medical history when AD’s case study was published. It’s typically caused by some kind of brain damage, and for AD, the hemi-PMO was connected to a lesion in the splenium region of his brain, which is an area associated with sight.

The crux of the condition is said to be comparable to facial recognition technology, which uses a library of images of faces to fill in the gaps when looking at a new face. It’s thought that when we see a face for the first time, we incorporate all historic examples of faces seen to create an image in our mind. In AD’s brain, it was a fault in the area of the brain responsible for this process that led to him viewing faces a bit like a Salvador Dalí painting.

PMO is also known as “demon face syndrome” because, well, it pretty much does what it says on the tin. A 2024 paper became the first to visualize how people with the condition see faces, and the results are pretty creepy.

At the time of its publication, there were around 75 reported cases of PMO, and though there’s still a lot we don’t know about it, this demonic distortion seems to be a common theme among some patients. Gaining a better understanding of how it affects people is crucial because it can be confused with other conditions like schizophrenia, leading to inappropriate treatments for a condition that’s actually linked to issues with the visual system.

Demon faces aren’t the only variety people with PMO have seen. As Lim writes in Horror On The Brain, there have also been reports of faces that looked glued together, turned into witches, looked like melting zombies, and even a woman who saw the faces of ordinary people morph into that of a dragon. 

“One of the case studies […] was described by Oliver Sacks, who is maybe one of my top favorite science writers of all time,” said Lim to IFLScience. “He describes a case where if this woman looked at someone’s face for long enough, she would see that face morph into the face of a dragon. Like, their skin would change color. A lot of the time it would turn to shades of purple. Their skin would also start developing scales, and their ears would get a little bit pointier. All sorts of unusual perceptual changes.”

It really is incredible what our brains can cook up when their processing goes a little haywire.