Imagine if every time you saw a face, it appeared distorted. For those who have a very rare condition known as prosopometamorphopsia, which causes facial features to appear distorted, that is reality.
As the website on what is known as PMO explains, “‘Prosopo’ comes from the Greek word for face ‘prosopon’ while ‘metamorphopsia’ refers to perceptual distortions.” The distortions can affect the shape, size, color, and position of facial features, and PMO 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 among the first to provide realistic visualizations of how a patient experienced facial distortions.
The patient, a 58-year-old male with PMO, sees faces without any distortions when viewed on a screen and on paper but sees distorted faces that appear “demonic” when viewed in-person. The case is especially rare because he does not see distortions of faces across all contexts.
If you take psychedelics something similar can happen, and it's way less intense with faces on screens. Maybe it has to do with depth perception?
I can think up a few plausible explanation. The easiest of which for me is that with a static picture of a face - especially if it's not Actual Size™ - your brain might be aware that it's not an actual face. Or more accurately, the visual system is not convinced that it's a real face.
At the end of the day though, I'm no brain scientist and I've got layman's knowledge about the subject at best, so I'm happy to leave it to the professionals and trust that the scientists verified it in one way or another.