‘When not seeing clearly is the reality, whilst what you do see clearly is not reality.’ This is the paradox faced in a life with Charles Bonnet Syndrome (CBS).
The vast majority of the population will never have heard of Charles Bonnet Syndrome. Put simply, CBS is a visual hallucination. It is entirely visual – no sounds are heard to coincide with what is being seen. It is not linked to any mental disorder. It happens as the brain tries to make sense of the surrounding environment by filling in the gaps caused by extreme sight loss. Hallucinations vary from seeing patterns and colours, animals, people or landscapes.
The condition, for which there is no cure or treatment, takes its name from the 18th century Swiss naturalist, Charles Bonnet. Bonnet’s first documented case, in 1760, was his 89 year old grandfather, who was almost blind from cataracts and reported ‘seeing’ a myriad of hallucinations such as people, birds or carriages. Despite this early discovery, CBS was not formally acknowledged by British psychiatrists until 1982.
Though the condition has very little public awareness, it is incredibly common in people with visual impairments and is frequently associated with many well-known eye conditions. Around half of people with Macular Degeneration experience some symptoms of CBS, according to the Macular Society, whilst a study led by researcher R. Nesher (2011) found evidence of CBS in 12.9% of people who were defined as having ‘low vision’ as a result of Glaucoma. An Australian study (led by O’Hare, 2015) found that over a third, 37.5%, of participants with Retinitis Pigmentosa, the leading cause of sight loss in the working age population, were affected by Charles Bonnet Syndrome.
Despite this high prevalence among the sight loss community, awareness of CBS is patchy among health and social care professionals. The charity Esme’s Umbrella was established in 2015, by Judith Potts (whose mother experienced CBS for many years) as a way of increasing awareness to wider society and providing support to those with the condition. Without this knowledge ‘most people suffer in silence because they are afraid of a mental health diagnosis,’ wrote Judith in The Telegraph (September 2015). This is a view backed up by one female (via Twitter), who on first experiencing signs of CBS thought she, ‘was cracking up… (The CBS was) Quite scary at times.’ And for those who do open up about their hallucinations, some have been misdiagnosed, most commonly with dementia.
Esme’s Umbrella has led to the condition being publicised in the national press and on national television but there is still a long way to go before CBS is known by the mainstream and recognised by professionals. It also needs mentioning more by ophthalmologists as sight deteriorates, so that if symptoms do start the patient already has awareness of the condition and is less likely to fear it. Only then will all who have Charles Bonnet Syndrome be able to deal with it openly and be able to access the right support.
By Sam Heaton (Newly diagnosed with CBS)