Charles Bonnet Syndrome (CBS for short) is the term used to describe the visual hallucinations that people who have significant bilateral vision loss sometimes experience. They usually know the hallucinations are not real but the hallucinations/visions take a wide range of forms from simple patterns of lines to complex and detailed pictures of people, animals, buildings and landscapes. When the visions are similar to an individuals normal environment it can be difficult to tell if they are real.
The existing research indicates that CBS affects at least 11-15 percent of those individuals who have bilateral vision loss of the 20/100 level or worse; it is most common amongst the elderly. It is believed that 15 percent is a low estimate since this is rarely a self-reported condition; many people who experience it think it represents mental illness. Unfortunately, CBS shares symptoms with some mental illnesses, which is what causes the confusion. It can then lead to a misdiagnosis, which only adds unnecessary stress to the sufferer. CBS has nothing to do with mental disorders– it stems primarily from a lack of visual stimuli.
This condition presents an opportunity to Rehabilitation professionals to educate their clients about a common condition that can be quite distressing to clients. It has resulted in serious misdiagnosis resulting in psychiatric confinement, the administration of needless medication and the establishment of guardianships.
Eye care professionals rarely ask their patients whether they have or are experiencing visual hallucinations and even less frequently tell them about the potential to develop CBS. General practitioners and Family physicians in many cases are not even aware that Charles Bonnet Syndrome exists.