Charles Bonnet syndrome

Hallucinations associated with Charles Bonnet syndrome (CBS) can be simple, non-formed images such as lines, light flashes, patterns, or geometric shapes. They also can be complex, such as images of people, animals, or scenes. They are usually not disturbing and do not involve other senses. People with CBS are generally aware that the hallucinations are not real and do not have an underlying psychological disease or dementia.^[1][2]

The timing and frequency of hallucinations can vary widely. The hallucinations tend to occur upon awakening. They usually last several minutes, but can be seconds or hours. Typically, there is a distinctive pattern to the timing and frequency of the hallucinations. The degree and complexity of the hallucinations also vary among individuals, but no association has been found between the complexity of the hallucinations and the severity of visual loss.^[1][3][4]

Associated symptoms depend upon the underlying disorder producing the visual loss. For example, strokes involving the visual pathways produce vision loss and sometimes other neurologic deficits, while macular degeneration and diabetic retinopathy produce loss of vision loss without neurologic deficits.^[1]

Charles Bonnet syndrome (CBS) is typically described as being associated with some form of visual impairment. People with CBS often present with a wide variety of eye conditions, with age-related macular degeneration being the most common. Although there appears to be a clear association between vision loss and CBS, it has been reported to occur in individuals with no obvious disease affecting vision. Additionally, it is possible for a person to have CBS due to an undiagnosed disease affecting vision.^[5] There are also several other causes of visual hallucinations that may be important to consider in people suspected to have CBS with no identifiable disease affecting their vision. For instance, people with certain neurological diseases, such as Parkinson's disease may experience visual hallucinations.^[2]

If you are concerned that you have CBS, but an underlying disease associated with vision loss has not been identified, we suggest working with your medical team to rule out other potential causes.