Mental Health Ocular System

Charles Bonnet syndrome (CBS)

Visual release hallucinations, also known as Charles Bonnet syndrome (CBS) is a type of visual disturbance and the experience of complex visual hallucinations in a person with partial or severe blindness in the absence of psychiatric .


The disease is named after the Swiss naturalist Charles Bonnet, who described the condition in 1760. He first documented it in his 89-year-old grandfather who was nearly blind from cataracts in both eyes but perceived men, women, birds, carriages, buildings, tapestries, physically impossible circumstances and scaffolding patterns.


Visual impairments:

  • Macular degeneration (central vision loss)
  • Glaucoma (peripheral vision loss)
  • Methyl alcohol poisoning
    • Bilateral optic nerve damage 

Clinical features

  • Fictive visual percepts
    • Vivid, complex recurrent visual hallucinations
  • “Lilliputian” hallucinations
    • Hallucinations in which the characters or objects are smaller than normal
  • Pseudohallucination
    • Involuntary sensory experience vivid enough to be regarded as a hallucination, but recognised by the patient not to be the result of external stimuli i.e. patient understands that the hallucinations are not real
  • Hallucinations are only visual
    • Faces or cartoons (M/C) > Animals, plants or trees and inanimate objects

Case study


There is no treatment of proven effectiveness for CBS.

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