The Visionaries
Change background colour
Leigh Vision Impaired Self Help Group

Charles Bonnet Syndrome

What is Charles Bonnet Syndrome?

Charles Bonnet Syndrome ( CBS for short ) is a term used to describe the situation when people with sight problems start to see things which they know aren't real. Sometimes called halluciations the things people see can take all kinds of forms from simple patterns or straight lines to detailed pictures of people or buildings. These can be enjoyable or sometimes upsetting.

A Swiss philosopher named Charles Bonnet first described this condition in 1760 when he his Grandfather who was blinded by cataracts described seeing birds and buildings which were not there. Although the condition was described very early it is still largely unknown by ordinary doctors and nurses. This is partly a lack of knowledge about the syndrome and partly because people experiencing it don't talk about their problems in case they are thought of as mentally ill.

Who's affected?

CBS affects people with serious sight loss and usually only the ones who have lost their sight later in life, it usually appears after a period of worsening sight.

What cause CBS?

At the moment little is known about how the brain stores the information it gets from the eyes and how the brain uses it to create the pictures we see. There is some research that shows that all the constant seeing prevents the brain from creating its own pictures. When people lose their sight their brain is not receiving as many pictures as it did, sometimes new fantasy pictures or old pictures stored in our brains are released and experienced as though they are seen. These experiences seem to happen when there isn't much going on , for instance when people are sat alone in a quiet familiar place, or when lay in bed at night.

Don't only mad people see things?

It is fairly normal for people who start seeing things to keep quiet about their visual hallucinations in case people think they are mentally ill. It is important to realise that failing eyesight and not mental illness is usually the cause of CBS.

There are other medical conditions such as Parkinsons Disease and Alzheimers, strokes and other brain conditions that can affect that part of the brain concerned with seeing,. Having CBS does not mean that you are more likely to develop any of these other conditions.

Another difference between the hallucinations that people with mental health problems and people with CBS have, is that in CBS people quickly realise that the hallucinations although interesting are not real. On the other hand, people with a mental illness have trouble telling the difference between reality and fantasy they will often come up with complicated explanations for the things they are seeing. If you think you are having CBS hallucinations tell your GP about them You may find it useful to print this page and take it with you.

What kind of things do people see?

There seem to be two different kinds of things people see. Both can be in black and white or in colour, involve still or moving images and can seem real e.g. cows in a field or seem unreal like pictures of dragons.

Firstly there are hallucinations of patterns or lines they can be like brickwork, mosaic or tiles.

Secondly more complicated pictures of people or places. Often scenes such as landscapes or groups of people, sometimes they can appear lifesize or sometimes tiny people and tiny things. They appear out of the blue and can last between a few minutes and a few hours. Many people begin to recognise similar things appearing in their visions such as distorted faces or the same tiny people.Generally the pictures are pleasant although the effects can be scary.

What effects?

Sometimes the complicated pictures can make it difficult to get around, for example streets and rooms may seem to change shape making it difficult to judge exactly where you are. One gentleman explained how once as he approached the top of the stairs he had visions of being at the top of a mountain, he had considerable difficulty getting back down the stairs. However a good knowledge of your surroundings can help overcome this problem.

The complicated pictures can sometimes be a little scary

Although the visions themselves may not be of anything frightening it is disturbing to start seeing strangers in your home or garden. People often over come this by getting to know the figures in their visions. One man describes how on waking up in the morning he says to the figures he sees "right what have you got in store for me today "? this allows him to have some control over the way he feels about seeing things.

So is there a cure?

Unfortunately at the moment there is know known cure or treatment for CBS. However just knowing that this is poor vision and not mental illness can help people come to terms with it. Generally these visions disappear after twelve to eighteen months, but of course this is not so for everyone with this problem.

It is worth trying to change things when the visions occur to see if this will help them disappear. For example if it happens in the dark try switching the light on, or off if it happens in the light, if you are stood up try sitting down if sat down try standing up.

Sometimes talking things over with a counsellor or psychiatrist can help provide people with ways of dealing with their visions. If you are having problems with yours then talking to your GP may be a good way to find some help.

Sources of support

At the moment the RNIB is not aware of any specialised support groups for people affected by Charles Bonnet Syndrome..