FRIDAY, Sept. 18, 2026 (HealthDay News) — Seeing people, flowers or patterns that aren't really there can be frightening. But for people with serious vision loss, these visions are often a known and harmless side effect, experts say.
The condition, called Charles Bonnet syndrome (CBS), causes vivid visual hallucinations in people who have lost much of their sight. Many people keep quiet about it because they fear they're developing dementia or a mental illness, according to The Washington Post.
Studies suggest CBS affects about 1 in 6 people with retinal disease or major vision loss. It's more common in people with the worst sight.
CBS most often occurs with age-related macular degeneration (AMD). This eye disease damages the macula, the part of the eye that handles sharp, straight-ahead vision.
About 11 million people in the United States have AMD, according to the U.S. National Eye Institute. The risk rises with age, especially after 55.
Varda Yoran, a 97-year-old sculptor in Brooklyn, New York, who is legally blind, once noticed a phantom street scene while waiting in a hospital wheelchair, The Post reported. At home, she sometimes sees strangers sitting in her living room.
She knew they weren't real, but she worried she was losing her mind.
Her daughter eventually found information about CBS online. Yoran's primary care provider agreed it matched her symptoms, The Post reported.
Part of the problem is that awareness is low, even among doctors.
"I think a lot of people are not familiar with it, even within the medical community. I don't recall being taught this in medical school," Dr. Surendar Purohit, a retina specialist at Specialty Eye Institute in Jackson, Michigan, told The Post.
His patients have described seeing people, patterns and geometric shapes. Often, family members are the first to notice something is off, he added.
Brain imaging research by Dr. Dominic ffytche, a professor of visual psychiatry at King's College London who does not capitalize his surname, has linked different kinds of hallucinations to specific parts of the brain's visual system.
"When the signals that normally come from the eye no longer come in, the cortex that's deprived of its input becomes more excitable," he told The Post. In other words, brain cells that no longer get input from the eyes can start firing on their own, causing hallucinations.
It's still unclear why some people with vision loss develop hallucinations and others don't.
Older adults often hide their symptoms out of fear of what they might mean, ffytche said. Talking about CBS before hallucinations begin can prevent much of that worry, he added.
Doctors should still check for other possible causes, ffytche noted. But CBS is a normal response to vision loss, and the hallucinations often become less intense and less frequent over time, even if they don't stop completely.
Yoran says knowing sooner would have made a real difference.
"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."
More information
Visit the Cleveland Clinic for more information about Charles Bonnet syndrome.
SOURCES: The Washington Post, Sept. 18, 2026; U.S. National Eye Institute, June 22, 2021