A different way of seeing things

Graeme Turner
What happens if, after you lose most or all of your vision, you start seeing things that aren't really there? Are you losing your mind? This is the situation faced by many people with vision loss or impairment who are experiencing Charles Bonnet Syndrome.
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Graeme Turner on 28/05/2013
Close up of the human eye

Research suggests that CBS may impact on up to 20% of those with vision loss.

Charles Bonnet Syndrome

Occasionally, with the decline of vision through a degenerative process, comes a strange and often confusing phenomenon that makes sufferers see things that are not there. This condition, called Charles Bonnet Syndrome (CBS), owes its name to Swiss naturalist Charles Bonnet. Bonnet first described its effects way back in 1769, after observing his vision impaired grandfather seeing images that were otherwise unexplained – men, women, carriages, birds and strange, geometric patterns.

Around 60 % of those with CBS report seeing a sort of overlay of abstract patterns. Others see more complex images, such as flowers, birds or even human forms and faces. While many images may be benign or non- threatening, some sufferers have also encountered visual hallucinations that include 'scary apparitions'.

Some images seem to arise from a person's particular interests. One man with a passion for racing cars reported seeing vehicles passing rapidly across his field of view. Curiously, some also report seeing people in elaborate period costume, which is somewhat inexplicable. This adds to the mystery of the condition, and explains why many sufferers are reluctant to talk about what they are seeing with family members or medical professionals.

Research suggests that CBS may impact on up to 20% of those with vision loss. Despite this, many eye specialists do not inform patients that they may experience these phantom images and, as a consequence, they might worry about their sanity.

Unlike the kind of visual hallucination attributed to psychosis and schizophrenia, those who experience CBS are generally aware that they are witnessing a sort of mirage. In scientific terms, it appears that when sight drops away, the brain tries to make up for the lack with images of its own. Much as an amputee might still 'feel' a missing limb, the brain continues to process information as though visual input has not ceased or been dramatically reduced.

New organisation

Concerned by the trend in people not being made aware of the condition, Scot Muirden established the Charles Bonnet Syndrome Foundation (CBSF), based in Melbourne's Ross House.

The goal of the organisation is quite clear to Scot. The primary aim is to offer services for those who are living with Charles Bonnet Syndrome, as well as to their spouse or family members.

Scot's mission is not just to raise awareness of the condition amongst groups who are likely to be affected, but also with eye specialists and other health professionals. CBSF aims to offer presentations to a range of groups in its first year of operation, advocating for greater awareness and appropriate treatment as well as an increased level of emotional support.

Scot would like to see the clinical profile of this condition raised enough so that anyone being treated for vision loss can rely on being given accurate and detailed information. Potential sufferers should be warned that images associated with CBS could and should be expected. They should also be reassured that these illusions aren't a sign of insanity or the onset of senility.

Losing your marbles

Because some suffers may think they are 'losing their marbles', CBS can be under-reported by as much as 30 to 70%. In the past, those with CBS have sometimes ended up in institutions, heavily medicated or sedated in an attempt to treat their 'delusions'. Having worked in both the mental health and vision impairment fields, Scot sees CBS as falling between the cracks of these areas. Scot was inspired by Patrick Moore, who was similarly concerned over the lack of service, and who founded the Macula Degeneration Support Society. Patrick has also experienced CBS and agreed to become involved in, and supportive of, Scot's new venture.

No cure but increased awareness

So, what can you do if you have CBS? Unfortunately there is no cure, but an awareness that this is not a mental health condition can help people cope. I would like to think that in five years a lot more people who live with Charles Bonnet Syndrome can talk about it a lot more freely, both with loved ones, family members, friends as well as any type of professional services that they're involved with, says Scot. Let's hope he's correct.

Further information can be found at www.charlesbonnetsyndrome.org.

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