As time passes from the initial onset of visual hallucinations, studies show that around 60% of those living with CBS feel that visual hallucinations have no effect on their lives, 33% of people feel that the hallucinations are disruptive to their lives, and 7% of people even find pleasure in the hallucinations.A large proportion of those suffering from CBS develop the visual hallucinations as vision begins to deteriorate and stop hallucinating once vision is entirely gone. Complex hallucinations may progress over time if the primary loss of vision is due to damage of the early cortical areas. If activation of the early cortical areas is suppressed when CBS symptoms have already been exhibited, hallucinations may temporarily terminate. Also, interrupting vision for a short time by closing the eyes or blinking may be helpful.It is possible for a stressful life event to alter the disposition of hallucinatory experiences as well as the emotional experiences (from unconcerning to concerning) in CBS. As expressed in some patients, an interplay between CBS and an acute or post-traumatic stress disorder may exist. The role that trauma plays in CBS may affect how and when a hallucinatory episode is triggered. History
The disease was first noted by the Swiss naturalist Charles Bonnet, who described the condition in 1760. He documented it in his 90-year-old grandfather who was nearly blind from cataracts in both eyes. After Bonnet’s grandfather received bilateral cataract surgery, his vision evolved from slightly better to complete deterioration over time. It was around this period that his visual hallucinations started.
The majority of those suffering from CBS describe the duration of hallucinations to continue for up to a few minutes, multiple times a day or week.Even though people of all ages may be afflicted by Charles Bonnet syndrome, those within the age range of 70 to 80 are primarily affected. Among older adults (> 65 years) with significant vision loss, the prevalence of Charles Bonnet syndrome has been reported to be between 10% and 40%; a 2008 Australian study found the prevalence to be 17.5%. Two Asian studies, however, report a much lower prevalence. The high incidence of underreporting this disorder is the greatest hindrance to determining the exact prevalence. Underreporting is thought to be a result of sufferers being afraid to discuss the symptoms out of fear that they will be labeled of unsound mind. Pathophysiology
There is no general consensus on the definition of CBS. Predominant factors correlated with CBS are a decrease of visual acuity, visual field loss, and elderly age. While characteristic features of visual hallucinations are not specifically linked to the anatomical site of the ocular injury, they usually match to the location of visual loss. The most commonly accepted theory for Charles Bonnet Syndrome proposes that extreme visual impairment promotes sensory deafferentation, leading to disinhibition, thus resulting in sudden neural firings of the visual cortical regions. A few studies record that visual hallucinations are likely to be concentrated in the blind regions.