Seeing, not believing

by Kathy Laurenhue on February 1, 2011

The following discussion article on tricks the brain plays is excerpted from the current issue of Brain Aerobics Weekly.

Author, humorist, and cartoonist James Thurber described these hallucinations:

  • 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 lady with a gray parasol walk right through the side of a truck.

He had these spontaneous visions – and many more – after he had gone blind. The engaging neurologist V.S. Ramachandran, M.D., Ph.D. suggests in his book, Phantoms in the Brain, that James Thurber had Charles Bonnet Syndrome or CBS. Like his friend and colleague Oliver Sacks, M.D., Dr. Ramachandran has made a career out of studying and helping people who have unusual brain disorders. The difference in the case of CBS is that it is not unusual, just usually hidden. As Dr. Ramachandran pointed out, “When Grandma, sitting in her wheelchair in the nursing home, says, ‘What are all those water lilies doing on the floor?’ her family is likely to think she has lost her mind.”

In fact, many people with CBS-related hallucinations, until they learn the cause, fear that they are going “bonkers.” They are hesitant to tell their loved ones or a physician of their symptoms, because they are afraid they will think so, too. It is true that hallucinations can be a side effect of various medications and a symptom of various serious diseases such as stroke, Dementia with Lewy Bodies (DLB), Alzheimer’s and Parkinson’s disease. However, Charles Bonnet Syndrome is more benign.

The syndrome is named after a Swiss philosopher named Charles Bonnet who described the condition in 1760 as it related to the visions of his nearly blind grandfather, who saw patterns, figures (including boyfriends for his granddaughters), birds, and buildings that were not there. The key differences from other disorders are that people with CBS already have impaired vision, and they realize – after their initial shock – that what they are seeing is not real.

According to the Lighthouse Organization (, “roughly one third of patients with low vision develop Charles Bonnet Syndrome, including those with age-related macular degeneration, cataracts, diabetic retinopathy, and other eye disorders. The hallucinations are more likely to occur when the person is awake, alone, and in dim light, or when he or she is physically inactive or lacks distractions, such as television.

Turning on an extra lamp or two, staying physically and mentally occupied, spending time with family or friends, and participating in social activities can reduce the frequency and vividness of the hallucinations.” Sometimes even blinking or turning away can help.

There is tremendous variance in frequency and duration of these hallucinations. They may last a few seconds or most of the day. They may occur multiple times each day or a few times a month. They may end altogether within days or go on for years. On average, they seem to disappear within 18 months. While there is limited drug treatment for the condition, it is not reliably effective. For most people, reassurance that this is a common syndrome and not a sign of mental illness is the best treatment. In fact, anxiety can easily change to amusement if you no longer fear the hallucinations.

After all, who wouldn’t be amused by visions like those described by a 73-year old woman before her diagnosis: She saw floating seahorses and featherless chickens that were then replaced by a Roman chariot with a rider dressed in gold. Tropical vines grew from the foot of her bed. Brightly colored fairies carrying wands beckoned her for walks around the hospital grounds.

After rattling off a number of his visions (golden sparks, melting purple blobs, saffron and light blue waves) James Thurber, in a letter to his ophthalmologist, wrote, “Man has devised no spectacle of light in any way similar to this sublime arrangement of colors or holy visitation.”

The most common images described by people with CBS are complex colored patterns (such as of brickwork, netting, mosaic, or tiles) and images of people; then come animals, plants or trees, and various inanimate objects. Sometimes the images are not in color; often the people, animals or objects are smaller than normal; sometimes they are distorted, with, for example, extra large teeth on one side. The hallucinations are visual only – without accompanying sound, smell, touch, or taste.

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