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31 May 2023

Charles Bonnet Syndrome: what is it and what help is out there?

Close up of someone's hands placed on top of another person's hands in a caring way.

This article was originally written for Insight magazine by Judith Potts, Founder of Esme’s Umbrella.

Have you ever come across Charles Bonnet Syndrome (CBS) in your favourite TV show? While it may be a new concept to many, it is a real and distressing condition that affects individuals with deteriorating eyesight. A Glaucoma UK member reached out to us, following a Coronation Street episode that featured CBS, asking if we could provide an article on the subject for our members. We are pleased to share this informative piece by Judith Potts, the founder of Esme’s Umbrella, a UK charity that aims to increase awareness of CBS and its impact on those affected.

Can you tell us a little bit about Esme’s Umbrella?

Esme’s Umbrella began as a campaign in 2015 and became a charity in 2022 which aims to raise awareness of CBS, to support people who live with the condition and to source funding for CBS research.

Who is Esme?

The Esme of Esme’s Umbrella was my mother. CBS tormented the last years of her life. Her waking hours were inhabited by vivid, silent, visual hallucinations of faceless people on her sofa, a wandering Edwardian child and a hideous gargoyle-like creature. Sometimes the whole room, or garden, morphed into an alien place. Yet – even when I had established the cause – not one of her healthcare professionals would acknowledge nor discuss the condition.

It was only when I discovered Professor Dominic ffytche at King’s College London – who is the sole, globally-recognised expert on CBS – that the culprit became clear.

What is Charles Bonnet Syndrome?

Esme had advanced glaucoma and, clearly, much more of her sight had been lost than I realised. When someone has full sight, there are messages which run all the time from the retina in the eye to the visual cortex in the brain. As sight diminishes, those messages slow down or stop entirely, leaving the brain inactive, with nothing to interpret. Consequently, it fires up and creates its own images.

The visual hallucinations are entirely silent. No other sense is involved and there is no interaction with the images. The sight loss can be caused by any one of the myriad eye diseases, or from stroke, cancer, accident to the eye, diabetes, multiple sclerosis or another condition which damages the optic nerve.

Most importantly of all, CBS is not a mental health issue.

Why was an awareness campaign needed?

At the time, I was writing a Health Column for the Telegraph and I wrote the first-ever piece about CBS. The response was overwhelming and it was obvious that this condition was affecting many more people – of all ages – than anyone recognised. It was shocking to hear how many people had been mis-diagnosed and ushered down the mental health pathway, wasting precious NHS resources and causing even more distress. The elderly found themselves admitted to dementia units by social workers or GPs who were unaware of CBS. With no one to explain or reassure them, I heard of people who stopped eating and drinking – with tragic consequences – because they hallucinated worms and slugs on food and in drink. It was too late when the correct diagnosis was given by the old-age psychiatrist, houses had already been sold to pay the bills, so there was no way back.

Even if CBS was recognised, knowledge was limited and out of date. Professor Dominic ffytche has debunked the myths surrounding this stigmatised condition. It is not rare – Esme was just one of, at least, 1 million people in the UK. It does not affect the elderly only – children are just as likely to experience CBS. It can develop when sight is lost from any condition – not just macular degeneration – and it does not disappear after 18 months.

What support is available for people living with CBS?

Creating Esme Room Support Groups was the first step to offer support. Then along came COVID-19. The groups closed but, within a week, it became obvious that the isolation and stress of lockdown were making CBS episodes more frequent and the images more frightening. People were desperate. Out of the pandemic grew Esme’s Friends, which began as telephone or online support groups – hosted by local, low vision charities and the RNIB – and these continue face-to-face or in a hybrid version. There are over 30 groups and I know what a lifeline they are for people. Discovering you are not alone and have peer support offers that all-important reassurance.

Are there any practical things that can help someone live with CBS?

Isolation, stress, fever and inactivity exacerbate CBS. Keeping the brain active can help to reduce the frequency of the episodes. Benign images – like cavorting kittens or beautiful flowers – can make the condition easier to tolerate, but the unpredictability of hallucinations is extremely debilitating.

Nina Chesworth lives with CBS every waking hour. She is a young, holistic therapist and copes with her condition by using yoga, mindfulness meditation, breathing techniques, plus lavender and ginger. Using these therapies, Nina is running a pilot project for Esme’s Umbrella, called ‘Knowledge, Acceptance and Management’, to determine whether or not KAM would work for others.

Until our researchers discover a CBS-specific medication, distracting the brain may help to quell the hallucination temporarily. Every experience of CBS is unique, but there are coping strategies which work for some people. These include reaching out to the hallucination, clapping the hands, clicking the fingers, standing up/sitting down, walking about, singing, whistling, turning on/off music, television, radio or using Professor ffytche’s eye exercise, which can be found on the Esme’s Umbrella website.

For people who retain enough sight, drawing or painting the images has proved popular. Recording a description of the hallucinations and listening to it may help to prove the images are not real.

What research is taking place?

Currently, there are CBS research projects running at Oxford University’s Nuffield Centre for Neurosciences, Cardiff, Manchester, Anglia Ruskin, Royal Holloway and London’s City Universities, along with Bravo Victor – the research arm of Blind Veterans.

Dr Kat da Silva Morgan – an Esme’s Research Fellow – led a study at Newcastle University which showed that the occurrence of CBS hallucinations can be significantly reduced by the use of a non-invasive electrical brain stimulation technique. Investment is needed now to optimise the treatment and allow it to be adopted by the NHS and used by people at home.

Professor Mariya Moosajee and Dr Lee Jones have proved prevalence in children and are now conducting a study to discover the impact CBS has on the child and the family.
A miniature cockapoo called Eliza, is using her extraordinary nose to lead a CBS study by Medical Detection Dogs to prove that there is a chemical change in the brain before the hallucination appears, which changes the odour of the skin and alerts the dog.

What are Esme’s Umbrella’s future priorities?

CBS needed to be recognised as a condition in its own right, not just as a side effect of sight loss. Two eminent ophthalmologists – Professor Andrew Dick here in the UK and Dr August Colenbrander in the USA – spearheaded the successful campaign and the World Health Organisation has given CBS a code in ICD 11.

Now, I am urging the NHS to create a pathway for diagnosis and treatment – with multi-disciplinary clinics so that CBS can be diagnosed correctly and swiftly. Also, to add a tick-box to the CVI form to prove that CBS has been discussed.

When I launched Esme’s Umbrella, I had absolutely no idea what was ahead of me. I just knew that I had to alleviate the fear, distress and misunderstanding – not to mention mis-diagnosis – of this debilitating condition.

If you’re interested in learning more about CBS, visit the Esme’s Umbrella website at or call their helpline on 02073 91 32 99.