Visual release hallucinations, also known as Charles Bonnet syndrome (CBS), are a type of psychophysical visual disturbance in which a person with partial or severe blindness experiences visual hallucinations.

First described by Charles Bonnet in 1760, the term Charles Bonnet syndrome was first introduced into English-speaking psychiatry in 1982. A related type of hallucination that also occurs with lack of visual input is the closed-eye hallucination.

Signs and symptoms

People with significant vision loss may have vivid recurrent visual hallucinations (fictive visual percepts). Depending on the content, hallucinations are classified as either simple or complex. Complex hallucinations may depict silent, non-interactive figures, whether multitudes of people, animals, or surreal objects, that appear life-like, as well as highly detailed landscapes or objects.

Those affected understand that the hallucinations are not real, although in some cases, particularly when cognitive decline progresses, they may begin to perceive them as genuine. The high incidence of underreporting this disorder is the greatest hindrance to determining the exact prevalence. Functional magnetic resonance imaging (fMRI) of Charles Bonnet syndrome patients displays a relationship between visual hallucinations and activity in the ventral occipital lobe.

Diagnosis

A variety of disciplines including optometry, ophthalmology, geriatric medicine, psychiatry, and neurology play a part in securing the diagnosis of CBS. Furthermore, treatment of underlying conditions that caused the visual loss could also remove or improve CBS associated symptoms. Those experiencing severe symptoms can also utilize behavior techniques such as repeated blinking during hallucinations, rapid eye movement from one object to another and bright lighting to engage the visual neural pathways. Lastly, social isolation, especially in the elderly has also been postulated as a possible etiological factor for CBS and therefore engaging with other individuals could also help alleviate CBS related symptoms.

Prognosis

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. As expressed in some patients, an interplay between CBS and an acute or post-traumatic stress disorder may exist. who was nearly blind from cataracts in both eyes. Even though his health was in good shape and he had an absence of any psychiatric disorders, the source of the hallucinations remained unknown. De Morsier's description of CBS implies a concentrated neurodegeneration, usually occurring in the elderly with typical cognition.

  • Vikram Chandra's book Sacred Games (2006)
  • David Eagleman's book Incognito: The Secret Lives of the Brain
  • Oliver Sacks's 2012 book Hallucinations
  • The Indian movie Jawan of Vellimala, released in 2012, in which Mammootty is a victim of the syndrome
  • The Black Canvas (2014), a chamber opera by the Greek composer Spyros Syrmos, is about a celebrated painter whose visions are caused by CBS.
  • Margaret Atwood's short story "Torching the Dusties"
  • Deborah Lawrenson's novel The Lantern (2011)
  • Gareth Brookes's graphic novel A Thousand Coloured Castles (2017)
  • Dealt, 2017 documentary about notable card mechanic Richard Turner
  • The 2019 Netflix film Velvet Buzzsaw
  • The Doc Martin episode "One Night Only" (2022, Season 10, Episode 2) depicts Dr. Ellingham diagnosing a patient with Charles Bonnet syndrome.

See also

References

  • Information on Charles Bonnet syndrome from RNIB
  • National Public Radio article with an audio segment about Charles Bonnet syndrome
  • Oliver Sacks: What hallucination reveals about our minds Ted Talk, Feb 2009.
  • Fortean Times article on Charles Bonnet syndrome
  • 'Damn Interesting' article on Charles Bonnet syndrome