Vision Loss Hallucinations Are Common, Harmless—But Few Know About It

Varda Yoran was sitting in a hospital wheelchair when the street scene appeared before her—a phantom landscape, vivid and complete, that she knew with absolute certainty was not there. The 97-year-old sculptor from Brooklyn, legally blind, had grown accustomed to her failing sight. But these visions were something else. At home, strangers would materialize in her living room. Flowers bloomed in patterns across her walls. She knew they weren't real. What terrified her was the possibility that she was losing her mind.

What Yoran was experiencing has a name: Charles Bonnet syndrome. It causes vivid visual hallucinations in people who have suffered severe vision loss, and it is far more common than most patients—or their doctors—realize. Research suggests the condition affects roughly one in six people with significant retinal disease or major vision loss. It strikes most frequently among those with age-related macular degeneration, the eye disease that damages the macula, the part of the retina responsible for sharp, straight-ahead vision. In the United States alone, about eleven million people have AMD, a number that climbs steeply after age fifty-five.

The hallucinations can take many forms. Patients report seeing people, flowers, geometric patterns, and intricate designs. Some describe phantom street scenes or rooms full of strangers. The visions are often startlingly detailed and completely convincing in the moment, even though the person experiencing them knows intellectually that nothing is actually there. What makes the condition particularly isolating is that most people who develop it stay silent about what they're seeing. The fear is overwhelming: they worry they are developing dementia, or that they are experiencing the onset of a psychiatric illness. That shame and terror keep them from telling anyone—even their doctors—what is happening.

Dr. Surendar Purohit, a retina specialist at Specialty Eye Institute in Jackson, Michigan, has heard these stories from his patients many times. He has listened to descriptions of phantom people, intricate patterns, and strange geometric shapes. Often, he notes, it is a family member who first notices something is wrong—a patient mentioning visions, or behaving in ways that suggest they are seeing things that are not there. Yet even within the medical profession, awareness of Charles Bonnet syndrome remains low. Purohit himself does not recall learning about it in medical school. The condition is simply not part of the standard curriculum for most physicians.

Brain imaging research has begun to explain what is actually happening. Dr. Dominic ffytche, a professor of visual psychiatry at King's College London, has used imaging studies to map which parts of the brain generate different kinds of hallucinations. His findings point to a straightforward mechanism: when the eyes stop sending their normal signals to the visual cortex, the brain cells in that region become hyperexcitable. Deprived of input from the eyes, these neurons begin firing on their own, generating the phantom images that the person perceives as real. It is, in a sense, the brain's attempt to fill a void—a normal neurological response to abnormal sensory deprivation.

What remains unclear is why some people with severe vision loss develop hallucinations while others do not. The condition does not indicate dementia or mental illness. It is not a sign of cognitive decline. It is simply a consequence of how the brain responds when it loses visual input. And importantly, the hallucinations often fade over time. They may become less intense, less frequent, or eventually disappear altogether, though some people continue to experience them indefinitely.

The tragedy, ffytche emphasizes, is that older adults often suffer in silence for months or years before learning what is actually happening to them. Early education—telling patients about Charles Bonnet syndrome before hallucinations begin, or as soon as they appear—can prevent much of that psychological distress. Doctors should still investigate other possible causes of hallucinations, he notes. But once CBS is identified, patients can stop fearing for their sanity and start understanding their condition for what it is: a harmless, if unsettling, side effect of vision loss.

For Yoran, learning the truth came only after her daughter found information about CBS online and brought it to her primary care doctor. The relief was immediate and profound. She had not been losing her mind. She was not developing dementia. She was experiencing a well-documented neurological phenomenon that thousands of other people with vision loss also endure. Looking back, she wishes she had known sooner. "It would have saved me a lot of nervous tension of thinking that I'm going crazy," she said. "We have the right to know what to expect."