Charles Bonnet Syndrome

Charles Bonnet syndrome is a common condition amongst people whose vision has started to deteriorate in which they begin to see things that aren’t really there (hallucinations). The hallucinations vary tremendously and can be anything from seeing a simple pattern to seeing more detailed images of people and places.

It is estimated that as many as 30% of adults who are affected by vision loss are affected by Charles Bonnet Syndrome although these figures are difficult to determine as so few people openly discuss any hallucinations they may have.

The syndrome is named after the Swiss naturalist and philosopher, Charles Bonnet who was the first person to describe the syndrome.

It is important to note that hallucinations caused by Charles Bonnet syndrome are caused by failing eyesight and do not occur as a result of a mental health problem or dementia. These hallucinations are only visual and are not accompanied by sounds or sensations.

Charles Bonnet syndrome may affect all ages but tends to occur later in life after a person’s eyesight begins to fail.


If you have lost some sight due to a condition such as glaucoma and you start to hallucinate and see things that aren’t really there, then you have Charles Bonnet Syndrome.

There are two main types of hallucination that are associated with Charles Bonnet syndrome. These hallucinations can be either simple repeated patterns such as shapes, lines or grids, or more complex hallucinations such as seeing people, places or animals.

Generally, these hallucinations are not unsettling or unpleasant however may be frightening when first experienced. Hallucinations can last anywhere from a few minutes to several hours and can be stationary or be moving.

Diagnosis, Screening and Tests

There is no specific test that can be used to identify Charles Bonnet syndrome. Doctors will generally look at a patient’s medical history, talk to them about their symptoms or carry out other tests to rule out other possible causes of hallucination.


Unfortunately, currently, there is no confirmed cure for Charles Bonnet syndrome.

No specific medication has been shown to stop hallucinations although some medicines used to treat other conditions such as epilepsy have proved effective for some individuals. These medicines do however have serious side effects, therefore, are only recommended for people who are severely affected or under close supervision.

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