The Mystery

Although Charles Bonnet syndrome (CBS) has been known of for quite some time, the condition continues to be shrouded in mystery. Medical and health care practitioners are often not aware of CBS as a clinical entity. Meanwhile, the people who are actually living with the condition tend to keep their visual experiences a closely guarded secret. This unfortunate nexus has ensured silence and mystery prevails.


CBS seems to remain a blind spot for medical practitioners and health care clinicians. One study reports that of 16 CBS-affected persons who consulted either their general practitioner (GP) or eye specialist, only one was given the correct diagnosis (Teunisse et al, 1996).

Furthermore, in an informal 2010 survey of 343 GPs in the Sydney metropolitan area, only two reported that they had heard of Charles Bonnet syndrome (0.56%). These two GPs admitted their knowledge of CBS was scant.

Client / patient

What further compounds the mystery is that somewhere between 40 - 65% of CBS-affected persons tend to not mention their symptoms to anyone. This includes a spouse or family member. It seems that the fear of:

  • being labelled 'crazy',
  • 'losing one's independence', 
  • 'worrying a loved one' or
  • 'not being taken seriously' are reasons that inhibit people talking about their CBS experiences.

With CBS-affected individuals generally not disclosing their symptoms (for understandable reasons), it has further contributed to the condition residing in a clinical and social void.

Mystery overview

  • The actual cause of CBS remains essentially unknown. 
  • Safe, reliably effective treatment for CBS is yet to be found.
  • Knowledge of CBS within the general community is virtually non-existent.
  • Knowledge of CBS within the medical and health care sectors is seemingly low.
  • What is known about CBS continues to poorly filter down to clinical settings and to the wider community.



Teunisse, R. et al (1996). Visual hallucinations in psychologically normal people: Charles Bonnet's syndrome. The Lancet, 347, 794-798.