The Hallucinations of Charles Bonnet Syndrome

Charles Bonnet syndrome causes those with visual loss to have complex visual hallucinations.  It was first described by Charles Bonnet, a Swiss philosopher in 1760.  Charles Bonnet’s grandfather suffered from the condition after losing his sight to cataracts.  It is believed that the vision loss may lead to a form of phantom vision.

Charles Bonnet syndrome is recognized as a common condition and the hallucinations are usually temporary occurring for 12-18 months before becoming a lot less frequent.  While the hallucinations are usually pleasant, they can become distressing at times.  They are vivid, complex and recurrent.  In the most common hallucinations, the characters are smaller than normal.  Hallucinations may also be of faces or cartoons.

There is no effective drug treatment, but knowing that the visual hallucinations are not being caused by a mental illness is a great comfort to those with the syndrome.  Anticonvulsants may help to stop the hallucinations.  The hallucinations may go away without treatment if vision improves or the issue of social isolation is addressed.

Charles Bonnet syndrome is most common in the elderly, but it can occur at any age.  Cases of the syndrome often go unreported because so many fear they are becoming mentally unstable and they don’t want to admit it. This made worse by the lack of awareness.  Research suggests that up to 60% of individuals who experience visual loss, no matter the cause, may develop Charles Bonnet syndrome.