Charles Bonnet Syndrome: My Personal and Professional Journey

Engraving of Charles Bonnet in profile. File source: Wikimedia Commons. This image is in the public domain because its copyright has expired.

This past week, I found myself involved in an interesting Twitter discussion about Charles Bonnet (“Bo-NAY”) Syndrome (CBS), a condition that causes vivid, complex, recurrent visual hallucinations, usually (but not solely) in older adults with later-life vision loss. The “visual hallucinations” associated with CBS can range from animated, colorful, dreamlike images to less complicated visions of people, animals, vehicles, houses, and similar everyday items.

My Charles Bonnet Journey

As I responded, I recalled my own personal and professional Charles Bonnet journey with one of my long-ago students, whom I’ll call “Doctor T.” It was Doctor T, along with neurologists Oliver Sacks and V.S. Ramachandran, who truly helped me understand abstract visual-perceptual issues and apply that understanding to real-life people living with CBS.

Oliver Sacks, M.D.

“Vision, in ordinary circumstances, is seamless and gives no indication of the underlying processes on which it depends. It has to be decomposed, experimentally or in neurological disorders, to show the elements that compose it.” ~Oliver Sacks, M.D. In the River of Consciousness

Throughout my professional career, I’ve relied upon Dr. Sacks’s deeply humanistic writings to develop my own case studies that acknowledge the complex interplay of factors – visual, perceptual, neuro-psycho-social – that define what it means to see … and not see.

Once upon a time, my case notes used to be terse “just the facts, ma’am” affairs, filled with medical notation that, as I came to understand, only served to obscure the human being who resided just beneath the surface of the vision loss. But over time, guided by Dr. Sacks’s gentle yet insistent literary prodding, I learned to address the deeper meanings of vision, perception, and, ultimately, human consciousness – as in the case of my longtime student Doctor T.

Doctor T was a leading physical chemist, at the forefront of molecular modeling, and author of several best-selling textbooks – until the moment he experienced toxic levels of radiation exposure during a scientific experiment. In that instant, the course of his life was altered forever, since the effects of this exposure were insidious, progressive, and culminated in total blindness; his eyes, lids, and soft palate liquified and eroded. I was contacted for an initial consultation and eventually became his primary daily living skills teacher.

Our progress was excruciatingly slow because Doctor T seemingly had lost the capacity to interpret the world tactually, aurally, or kinesthetically. In my case notes, I observed that his blindness had impaired his global abilities far beyond what one would usually expect in the case of such an injury. I also observed that he would flinch periodically and appear to dodge invisible objects – invisible to me, at least.

Eventually, I broached the subject and asked what might be causing these unusual movements:

“I’ll tell you,” he said, “but I know you’ll think I’ve lost my mind.”

“Go ahead,” I answered. “I don’t think you’re crazy, but I am interested in why you’re moving this way.”

“I see things,” he said. “When I’m talking with you in the kitchen, sometimes I see a big yellow school bus filled with students, driving through the wall toward us. I know it’s not really there, but I still feel as if I have to get out of the way.”

“What else do you see?” I asked.

“Sometimes, when I’m walking into the living room, I see two people dressed in colonial outfits, standing side-by-side, just watching me. These things scare me so much. I don’t know what to do to make them stop.”

And that’s when I began to learn all I could about Charles Bonnet Syndrome. Doctor T’s psychiatrist and I embarked on a learning frenzy, trying – or so it seemed – to read every article ever written about this little-known (at that time) neurological disorder. You can read some of what I learned, including causes, treatments, interventions, and resources at Charles Bonnet Syndrome: Why Am I Having These Visual Hallucinations?

I highly recommend the 2009 “TED Talks” video, entitled Oliver Sacks: What hallucination reveals about our minds. Dr. Sacks discusses Charles Bonnet Syndrome, describes the experiences of his patients, and explains the biology behind the Charles Bonnet phenomenon.

V.S. Ramachandran, M.D., Ph.D.

“One could argue that the term consciousness doesn’t mean anything unless you recognize the emotional significance and semantic associations of what you are looking at.” ~V.S. Ramachandran, M.D., Ph.D. Phantoms in the Brain: Probing the Mysteries of the Human Mind

Neurologist V.S. Ramachandran has been another major influence in my Charles Bonnet journey. Interestingly, in Phantoms in the Brain, he suggests that the American author, humorist, and cartoonist James Thurber may have had Charles Bonnet Syndrome. Dr. Ramachandran writes that Thurber, who was severely visually impaired from childhood as the result of a playground accident, described a number of vivid visual “hallucinations” in correspondence with his ophthalmologist:

  • I saw bridges rise lazily into the air, like balloons.
  • I saw a cat roll across a street in a striped barrel.
  • I saw an old woman with a gray parasol walk right through the side of a truck.

Dr. Ramachandran also describes additional Thurber visions encompassing “golden sparks, melting purple blobs, and saffron and light blue waves” and concludes that Thurber’s vivid creative literary imagination might be explained partially by Charles Bonnet Syndrome. You can learn more about Dr. Ramachandran and his work in A conversation with neurologist V.S. Ramachandran, a video interview with Charlie Rose.

A Thank-You To My “Teachers”

I thank Doctor T, Dr. Oliver Sacks, and Dr. V.S. Ramachandran for reminding me – and all of us – what it means to be deeply, at times uneasily, but always fully, human.