Charles Bonnet syndrome (or 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 visual hallucinations the things people see can take all kinds of forms from simple patterns of 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 the 1760 when he noticed his grandfather who was blinded by cataracts describing 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 because of a lack of knowledge about the syndrome and partly because people experiencing it don't talk about their problems out of fear of being thought of as mental health difficulties.
Charles Bonnet syndrome affects people with sight difficulties and usually only people who have lost their sight later in life. But it can affect people of any age, usually appearing after a period of worsening sight. The visual hallucinations often stop within a year to eighteen months.
At the moment little is known about how the brain stores the information it gets from the eyes and how we use this information to help us create the pictures we see. There is some research that shows that all this constant seeing actually stops the brain from creating its own pictures.
When people lose their sight their brains are not receiving as many pictures as they used to. Sometimes, new fantasy pictures or old pictures stored in our brains are released and experienced as though they were seen.
These experiences seem to happen when there is not much going on, for example when people are sitting alone, somewhere quiet, which is familiar to them, or when they are in lying in bed at night.
It is fairly normal for people who start to see things to worry about there being something wrong with their minds. Seeing things is often a sign of mental health difficulties and the threat of Alzheimer's can often be a worry. People often keep quiet about their hallucinations for fear that people will think they are losing their minds. It is important to realise that failing eyesight and not any other mental difficulties normally causes CBS.
There are other medical problems, which can cause people to see things: Parkinson's disease, Alzheimer's, strokes and other brain conditions which effect 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, which people with mental health problems and people with CBS have, is that in CBS people quickly learn that the hallucinations although interesting are not real. On the other hand, people with a mental health difficulties have trouble telling the difference between their fantasies and reality and will often come up with complicated explanations for the things they are seeing (sometimes called a delusion).
If you think you are having Charles Bonnet Syndrome hallucinations then tell your GP about them. You may find it useful to take this leaflet along with you to show to your doctor.
There seem to be two different kinds of things people see. Both of them can be black and white or in colour, involve movement or stay still, and they can seem real, such as cows in a field, or unreal, such as pictures of dragons.
Firstly, there are the hallucinations of patterns and lines, which can become quite complicated like brickwork, mosaic or tiles.
Secondly, there are more complicated pictures of people or places. Often whole scenes will appear such as landscapes or groups of people, which are sometimes life size and other times tiny people and tiny things. These pictures appear out of the blue and can carry on for a few minutes or sometimes several hours. Many people begin to recognise similar things appearing in their visions such as distorted faces or the same tiny people in particular costumes.
Generally the pictures are pleasant although the effects can be scary.
Sometimes the complicated pictures can make it difficult to get around. For example, streets and rooms may have their shape changed and this can make it difficult for you to judge exactly where you are. A gentleman described how once approaching the top of the stairs he had a vision of being on top of a mountain and had considerable problems getting down the stairs. However, good knowledge of your immediate surroundings can help overcome this particular 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 in your garden. People often over come this by getting to know the figures in their visions. One man describes how when he wakes up in the morning he says to the figures he is seeing: "right what have you got in store for me today?". This allows him to have some control over the way he feels about his seeing things.
Unfortunately at the moment there is no known cure or treatment for CBS. However, just knowing that it is poor vision and not mental illness that causes these problems often helps people come to terms with them. Generally these experiences will disappear after about a year or eighteen months but of course this will not happen for everyone with the condition.
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 then try switching a light on or if it happens in the
light try switching the light off. If it happens when you are sitting
down then try standing up.
Sometimes talking over feelings with a counsellor or psychiatrist can help provide people with ways of coping with the visions. If you are having problems with yours then talking to your GP may be a good way to find some help.