Charles Bonnet Syndrome: Vivid, silent, visual hallucinations after sight loss ignored for decades
As sight diminishes, the brain is left with little or nothing to interpret. Not used to being idle, it fires up and creates its own images. These vivid, silent, visual hallucinations are called Charles Bonnet Syndrome (CBS) – named after the Genevan naturalist who documented what was happening to his grandfather in 1760, but which is only now being highlighted.
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Hide AdImagine having lost some sight – the amount is different for everybody who lives with CBS – and suddenly being confronted by a tiger, people standing in the room or flames emerging from your bed. Utterly terrifying and, until recently, a well-kept secret because too many people who developed CBS assumed – incorrectly – that the visual hallucinations heralded a mental health condition and confided in no one. This led healthcare professionals to believe it was a rare condition – but the very opposite is true. There are, at least, one million people in the UK who live with CBS.
Esme
My late Mother, Esme, was in her early nineties. She had glaucoma – a common eye condition where the optic nerve connecting the eye to the brain, becomes damaged – and, gradually, her sight became worse. Then she found that she was sharing her fragile, cloudy-sighted world with faceless people sitting on her sofa, a child in Edwardian costume, hideous gargoyle-like creatures and whole scenes which filled her home with alien environments.
As Charles Bonnet described his grandfather, Esme was ‘of sound mind’, completing correctly the Telegraph cryptic crossword every day and coping admirably with her sight loss. No warning had been given to her by the ophthalmologist nor the optometrist. It was only when her CBS became impossibly distressing, that she finally confided in me about her ‘visions’. I had absolutely no idea what could be wrong with her, although the word ‘dementia’ lay, unspoken, between us.
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Hide AdLuckily, a factual paragraph in a newspaper gave me the answer, but when I tackled the ophthalmologist, asking why he had not warned us that this might happen, he refused to answer or discuss CBS.
What is CBS?
I discovered that the world authority on visual hallucinations of all types – and CBS’ first researcher - is Professor Dominic Ffytche at King’s College London. I paid him a visit. He explained that CBS is not a mental health condition but caused entirely by the lack of messages which, with full sight, run from the eye – acting like a camera – to the brain for interpretation. Why the brain should fire up and create these hallucinations is still not clear, nor is the choice of image made by the brain. Some people see beautiful and benign images, while others are beset by horrors.
CBS can develop when sight is lost from any one of the myriad eye diseases, from stroke, cancer, accident, diabetes, multiple sclerosis, a brain injury or another condition which damages the optic nerve.
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Hide AdFar too few healthcare professionals of all specialties are aware of CBS and those who are often labour under the myths that it only happens to the elderly, that what is seen is always beautiful and that it will disappear after 18 months. From Professor Ffytche’s work, we know that none of that is true.
CBS occurs in all age groups
Miles Northwood – now in his early fifties - lost his sight aged 4 and, shortly afterwards, began to see monsters but told no one. These hallucinations have plagued his entire life and it was only a few years ago, when he discovered that the hallucinations had a name and he was not losing his mind, that he shared his frequent CBS episodes with his wife. Talking about what he sees has proved to be extremely beneficial.
Young Mum, Nina Chesworth, lost her sight from two accidents. After surgery from the second accident, she woke to see bright colours. Thinking that the surgeon had saved her sight, she was thrilled, but what she was seeing was a version of CBS. Since then, she has lived with visual hallucinations every waking hour.
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Hide AdEsme’s Umbrella
Esme gave her name to the Campaign, now a charity, called Esme’s Umbrella, which I founded in 2015 to raise awareness of this distressing and perplexing condition. Since then, the World Health Organisation has accepted that CBS is a condition in its own right and given it a code in the taxonomy of diseases and conditions (ICD11); awareness has been raised with many more people reaching out for information; research has begun in the UK, inspiring other countries to follow suit; support groups have sprung up and counsellors are learning about CBS.
Living with CBS
Not everyone sees frightening images but there is no doubt that living in a world of visual hallucinations has a massive impact on quality of life. As the images are incredibly sharp and clear, many people who retain a small amount of sight, are unable to distinguish between what is real and what is not. Wary of falling over, they become house-bound, with all its implications for their own health and the cost to society.
The lockdowns of COVID 19 showed us that isolation, stress, and fever cause an escalation in the number of episodes and the images seen are more frightening than usual. Certain other conditions and the side effect of some common medications can also exacerbate CBS.
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Hide AdDistraction techniques can be of help for some people and, if the hallucinations are unbearable, medication used for dementia and epilepsy can be tried. This does not mean the person has developed either of those conditions. As yet, there is no CBS-specific medication but, with a greater awareness, there is a growing interest in researching treatments and, ultimately, finding a cure.
Children and Young People
This year, Esme’s Umbrella is focusing on children who live with CBS. Awareness of the condition among parents, caregivers and teachers is woefully inadequate. Paediatric ophthalmologists and optometrists have not been discussing CBS with parents and caregivers – or with the children. Indeed, many of these healthcare professionals were not even aware that children could develop CBS – although, logically, why not?
We are in the foothills of this research but, already, we know that CBS hallucinations are creating a true ‘nightmare’ for children and young people.
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Hide AdConsequences
CBS may not be a mental health condition but it can lead to anxiety and depression in all ages. Consequently, there is a huge need for CBS specialists, so that a proper pathway for diagnosis, treatment and support can be created. The NHS has a duty of care to the whole CBS community and, at the moment, that is not being fulfilled.
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