Article from Esme's Umbrella
General Optical Council eBulletin 34
September 2017

Article from Esme's Umbrella

Esme’s Umbrella is the campaign group working towards a greater awareness of Charles Bonnet Syndrome (CBS). In 1760 naturalist and philosophical writer, Charles Bonnet, described a condition in which vivid, complex visual hallucinations occur in psychologically normal people. He documented it in his grandfather who was nearly blind from cataracts in both eyes but perceived men, women, tapestries and scaffolding patterns. 

CBS is an extremely common, but under-researched and little understood condition. The vivid, silent and visual hallucinations which it produces, range from disturbing to terrifying. As the images come from the brain, they are sharp and clear, which makes them all the more frightening. Learning to take a deep breath and telling yourself that the pit bull terrier in front of you – with its sharp teeth and drooling jaws – is not real and will disappear if you reach out toward it, is not easy.

Most people affected are elderly with visual impairments, however, the phenomenon does not occur only in the elderly or in those with visual impairments; it can also be caused by damage elsewhere in their optic pathway.

Many healthcare professionals are unaware of the condition and misdiagnosis is common – the medical assumption being that hallucinations herald dementia, even in a patient who is clearly not suffering from any mental health issue. Far too many people suffering from hallucinations assume this too and live in frightened silence plagued by their hallucinations. 

Current research by Dr Dominic ffytche of King’s London (medical adviser to Esme’s Umbrella and the sole globally-acknowledged expert in CBS) has shown that the condition may last for the rest of the person’s life. Some people can be helped with drugs used to treat other conditions, but there is no treatment to dispel the hallucinations. 

More research into the condition is needed; we still do not know why only some people with sight loss have hallucinations. The stress caused by living 24 hours a day with the uncertainty of what is real and what is not, results in people becoming seriously depressed. People become afraid to leave the house; afraid to confide in family and friends, who can be sceptical or lose patience – even if CBS has been diagnosed.

However bizarre, funny or terrifying in their content, Charles Bonnet hallucinations are no more than a normal brain’s response to reduced visual input, but it is vital that patients are given reassurance and understand that they are not a cause for concern. 

Information for optical professionals on supporting patients with CBS are available on our website Patients can also be directly referred to Esme’s Umbrella - by email to Judith Potts, Founder of Esme’s Umbrella, at or the Helpline on 0345 051 3925 (answered 24/7 every day). 



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