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What is Charles Bonnet syndrome?

Charles Bonnet syndrome (CBS) is a common condition among people with poor vision. It is when you experience silent visual hallucinations. These can seem real and can be confusing or frightening. They are caused by the brain trying to ‘fill in’ detail in the blind areas. The hallucinations usually decrease or disappear over time.

Who is affected by Charles Bonnet syndrome?

Anyone, including children, who has an eye condition that results in sight loss can develop Charles Bonnet syndrome. However, it is more common in older people as they are more likely to have conditions, such as age-related macular degeneration, cataract, glaucoma or diabetic eye disease, which result in sight loss.

What are the symptoms of Charles Bonnet syndrome?

We don’t know why sight loss leads to hallucinations, but it is thought that the brain fills the gaps in your vision by releasing new images or old images that it has stored. This can start in the weeks following your sight loss. You may worry that you have Alzheimer’s disease or a mental health problem, but Charles Bonnet syndrome is a result of the sight loss and is not associated with any other health problem. Symptoms include:

  • visual hallucinations – these can be very vivid and include known and unknown people and animals
  • distorted vision – rooms may appear to change size and shape, making it difficult to get around.

How do you treat Charles Bonnet syndrome?

Currently, there is no cure for Charles Bonnet syndrome and no specific medication has been shown to stop the hallucinations. Some medications that are designed to treat epilepsy, Parkinson’s disease and dementia have proved effective for people who are severely affected. Usually, the hallucinations will become less frequent and vivid and may stop altogether. However, they may restart if there is another sudden, significant loss of vision.

There are some things you can try to help relieve your symptoms:

  • make sure you’re well rested and are getting enough sleep at night
  • change the lighting to make the room brighter or darker or move to another room or location
  • move your eyes from left to right without moving your head . Do this every second 15 times without moving your head, then pause for a few seconds and repeat four or five times
  • stare at the hallucination and blink rapidly or reach out to touch the vision
  • move somewhere else and do something else.

Charles Bonnet syndrome advice, information and support

The Macular Society runs a buddy service for people affected by Charles Bonnet syndrome. Telephone the helpline during office hours (Monday to Friday, 9am to 5pm) 0300 30 30 111.

Esme’s Umbrella

NHS Choices

RNIB.org.uk