In 2007, Jason Werbeloff, a twenty-two-year-old graduate student in Johannesburg, South Africa, spent months in bed with a severe case of mononucleosis. Every part of his body—his joints, his skin, his swollen throat—was in pain, and he passed the time staring at the concrete ceiling of his room. Television gave him a headache; he tried to read but often forgot the names of characters by the end of each page. He saw no one except his mother, who occasionally stopped by with groceries.
After he recovered, Werbeloff was eager to be around people again, and he spent a night clubbing. In the shifting red light, he looked at a friend’s face and realized that the right side looked odd. It seemed to stretch outward, like Silly Putty being pulled, and a dark, rough patch was visible around the friend’s right eye. Werbeloff blinked and looked away, and his friend’s features briefly returned to normal. Then the distortions appeared again. “That is when people got ugly,” Werbeloff told me.
In the weeks that followed, Werbeloff started to notice similar unsettling changes in everyone he looked at. “If they were smiling with their teeth very visible, then, on the right-hand side, the canine tooth would elongate,” he told me. Even his own face in the mirror looked malformed on the right. He had long known that his ability to recognize faces was so poor that it bordered on prosopagnosia—face blindness—but now he wondered whether he suffered from something else. He worried that he harbored an unconscious dislike for almost everyone he met.
For fourteen years, Werbeloff treated the facial distortions as an uncanny and ever-present part of his life. He grew accustomed to looking away from faces periodically, so that they would temporarily return to normal. Then he came across a curious Facebook post in a group for people with prosopagnosia. The author of the post wanted to know whether anyone else had seen faces morph into strange configurations. When Werbeloff said yes, he was told to e-mail Brad Duchaine, a professor of psychological and brain sciences at Dartmouth College, who was studying the phenomenon.
In May, 2021, Duchaine interviewed Werbeloff via Zoom. Had Werbeloff suffered any traumatic brain injuries? (No.) Did he ever see faces change before his bout with mono? (No.) Did he see distortions on half of the face, or all of it? (Only the right half.) Duchaine said that Werbeloff seemed to have a rare and largely unexplained condition called prosopometamorphopsia, or PMO. He was trying to meet as many PMO sufferers as he could—not only to identify why the distortions were occurring but to illuminate the intricate way in which the human brain perceives faces.
During the Zoom call, Duchaine’s Ph.D. student Sarah Herald asked Werbeloff to stare at portrait photos for longer than he was used to. Werbeloff hadn’t realized how distended a face could become: the right side stretched until it was bulging, and the dark patch became a deep concave pit encircling the eye. After the session, Werbeloff cried. “I don’t believe in demons,” Werbeloff told me. “But I can totally understand that someone who was religious would find it a deeply religiously disturbing experience.”
This past April, for the first time, Werbeloff visited Duchaine at Dartmouth, where he had his brain imaged while looking at faces under different conditions. A few days later, on a blustery morning in Manhattan, he met me on the steps of the Metropolitan Museum of Art. Werbeloff is now thirty-nine, with short curly hair and brown glasses. He owns a marketing company and hosts Brain in a Vat, a YouTube channel about philosophy. I found his face easy to look at, but I knew that mine might not be, so we sat side by side. (Over the years, he has realized that faces in profile appear less distorted to him.)
Werbeloff speaks in a crisp South African accent and seems to choose his words with care. As we watched throngs of museum visitors go by, he told me that he didn’t see distortions if he made sure not to look at any face for more than three seconds. This was possible in a crowd, he went on, but not in intimate relationships. He remembered a time before his condition began, when he dated a man for three and a half years. “From the day I met him until the day I left him, his face didn’t become any less beautiful,” he said. But, since he developed PMO, merely gazing at his loved ones has caused their faces to change. “That was a huge loss,” he told me. “I couldn’t see someone as they were.”
In 1947, Joachim Bodamer, a German neurologist, wrote about three patients who struggled with the perception of human faces. Two of the patients had difficulty with recognition, and Bodamer came up with the term “prosopagnosia” to describe them. A third patient, whom Bodamer called Patient B, saw faces as “distorted or displaced.” To this person, the neurologist wrote, “a nurse’s nose was turned sideways by several degrees, one eyebrow was higher than the other, the mouth was squinted, and the hair shifted like an ill-fitting cap.” Scientists ultimately published hundreds of papers on face blindness, and Oliver Sacks wrote about it for this magazine. (“On several occasions I have apologized for almost bumping into a large bearded man, only to realize that the large bearded man was myself in a mirror,” he wrote, in 2010.) Patient B’s condition, however, went largely unexplored. Macdonald Critchley, a British neurologist, was one of only a few scholars who studied visual aberrations that specifically affect the face; in the nineteen-fifties, he introduced the term “prosopometamorphopsia,” from the Greek for face (prosopon); to distort (metamorphoun); and sight (opsis).
In 2011, a Dutch woman named Ellen Novara-da Lima sent Sacks an e-mail. “I am a woman of 52 years old and I suffer from an illness,” she wrote. “I think there’s no name for it. I see monsters, ugly faces all day.” Because Sacks couldn’t evaluate her from New York, he referred her to a neurologist in the Netherlands, Jan Dirk Blom, who published a paper about her, with Sacks as a co-author. “She could perceive and recognise actual faces, but after several minutes they turned black, grew long, pointy ears and a protruding snout, and displayed a reptiloid skin,” they wrote. Sacks and Blom diagnosed her as having PMO.
Blom works at a nondescript psychiatric facility that is tucked into a medical and business complex in The Hague. When I visited him there, in 2023, I presented my I.D. at the front desk and followed him to a sterile exam room. He wore an authoritative gray suit and polished dress shoes. When he started to research PMO, he told me, there was very little published work on the subject. By reading old case studies, however, he was able to identify seventy-three historical patients who seemed to have experienced the condition. An early account, published in Berlin in 1904, said that, after a seizure, a thirty-seven-year-old woman saw a change in her reflection which gave her “large, contorted eyes.” Five years later, a paper described a seventy-three-year-old stroke patient who began to see familiar faces as “large, strange, and grimacing.” In 1916, a German doctor wrote that a thirty-five-year-old woman, who had an unusual form of migraines, often saw “grotesquely disfigured faces.”
One of the first visual depictions of PMO dates to 1965, when an artist, who had had a tumor removed from the left side of his brain, saw distortions on the right half of people’s faces. TNP, as the patient was called in the case report, drew a smiling nurse in a white cap; a pink vortex swirled where the nurse’s right eye should have been. When TNP looked at a doctor’s face, he reported that “the eye became a ghastly staring hole, cheekbone a cavity; he had teeth on the upper lip, often had two ears” on the right side.
In 2019 and 2020, eight people with PMO came to Blom’s clinic. A middle-aged man saw skin where people’s right eyes should have been. A young woman told them that, for three weeks, she had perceived the left side of people’s faces as melting, and had seen their left eyes appear to fall toward their cheeks. Another woman painted the distortions she saw in her own reflection: her head getting larger, furrows on her forehead, and then a shrinking of her body and a brightening of colors. (She didn’t like to look at the painting, so she gave it to Blom.)
Distorted perceptions are not the same as hallucinations, Blom told me. If you saw an elephant appear in your home office, you would be hallucinating. But, if you looked up and perceived an elephant in an elephantine cloud, that’s more like a distortion. “There’s a cloud—it’s actually there,” he said. He views his PMO patients as very different from psychiatric patients with schizophrenia, who hear voices or see things that don’t exist. People with PMO aren’t helped by antipsychotics; they know that what they’re seeing isn’t right. Blom suggested that PMO could fall under the umbrella of Alice in Wonderland syndrome, a collection of neurological symptoms that can be provoked by migraines, epilepsy, viral infections, or tumors, and which distort a person’s perception of their own body and the world around them.
As a clinician, Blom is most concerned with alleviating symptoms, if he can. Although there is no known cure, he has found that some distortions go away with medications for epilepsy. Others simply fade on their own, in the way that migraines come and go. But for those who continue to experience distortions, Blom said, the condition undermines a central part of the human experience. “We’re constantly observing each other, and looking at all these micro-expressions,” he told me. His patients with PMO had lost access to the stories we tell with our faces: that we are curious, or bored, or annoyed; that we are lost in thought, or in love, or need to hear that last sentence again. I suddenly became aware of Blom’s eyes on me, and of all that my face was telling him.
The human brain seems drawn to faces from birth. One study found that newborns, in their first minutes of life, tended to follow printouts of faces with their eyes; they were much less interested in scrambled images of facial features, or in blank pages. We even see faces where there aren’t any—for example, in electrical outlets and emoticons. In the nineties, neural imaging revealed that parts of the fusiform gyrus—a brain region near the base of the skull which is associated with vision—are more active when people see faces. A team led by Nancy Kanwisher, a neuroscientist at Harvard, named these regions the fusiform face area, or FFA.
Neurologists often learn by studying brains that aren’t working as expected. Damage to the FFA, whether through stroke or injury, can erode one’s sensitivity to faces, and to human faces in particular. In a case study from 1993, a man developed face blindness after a stroke and then became a farmer. He struggled to tell people’s faces apart, but could consistently distinguish between his sheep.
PMO could offer another opportunity to deepen our understanding of facial recognition—something to which Duchaine has dedicated his scientific career. In his lab, in Hanover, New Hampshire, faces are everywhere: portraits of Duchaine and his students hang on the wall; cartoonish pictures of eyes, eyebrows, a nose, and a mouth dangle from a nearby “facial-expression mobile.” “Face Book,” a collection of paintings by Chuck Close, sits on the coffee table. During my visit, this past October, Duchaine led me into his office and talked me through the regions of the brain, holding up his large hands to represent each hemisphere. (Duchaine’s own facial-recognition abilities are “below average,” he told me; his wife teases him for thinking that people with similar hair look alike.)
Duchaine first heard about PMO while studying face blindness. He was surprised when studies and surveys suggested that around two per cent of the population develops the condition. In 2021, he created a Web site that asked people who see facial distortions to get in touch, in the hope that a similar hidden population might surface. Around a hundred and fifty people have reported facial distortions to his team—a number suggesting that, around the world, thousands of people may experience them.