How you know if you have CBS

“I always thought that seeing things was a sign of mental health problems”.

If you have lost some sight to a condition like macular degeneration or glaucoma and you start to hallucinate or see things that aren't really there, then you may have CBS.

There isn't one test that your doctor can do to find out whether you have CBS or not. Usually by talking with you and in some cases doing tests, your doctor will be able to rule out the other causes of hallucinations, like mental health problems, Alzheimer’s and other conditions. If there are no signs of these other conditions and you have lost sight, then it is probable that CBS is the cause of your hallucinations.

It’s natural to be worried, confused or frightened when you see things that are not really there. Until you know what's happening, you may be concerned that seeing things is a sign of a mental health problem, or you might think that you have Alzheimer’s disease. However, it’s important to remember and reassuring to know that CBS is caused by sight loss only and not by any other health problem.

If the hallucinations cause you to feel anxious, you may also feel like you want to keep quiet about the things you are seeing. However, even though there is no cure for CBS, letting people know that you have this problem or talking about it may offer you some peace of mind. There is more information on “talking about CBS” later in this booklet.

There are some medical problems, such as Parkinson’s disease, Alzheimer’s disease, strokes, serious mental illness and other brain conditions, which affect the part of the brain concerned with seeing and these conditions may cause some people to have hallucinations.

**It’s important to remember that having CBS does not mean you’re more likely to develop any of these other conditions. Sometimes, if you have one of these conditions as well as CBS because of sight loss, it can make your hallucinations more frequent.**

Certain things about CBS hallucinations make them different to the hallucinations caused by other conditions. Usually, with CBS you're aware – or can learn to recognise – that what you're seeing isn’t real, although it may appear vivid. CBS hallucinations only affect your sight, which means that you don’t hear, smell or feel things that aren’t there. People with CBS do not develop any obvious, complicated non-medical explanation about the cause of their hallucinations (sometimes called “delusions”). For example, someone with CBS wouldn't have thoughts that the people they were seeing wanted to hurt them.

If one day you find that you’re seeing a pattern, person, building or a landscape that you know is not really there, then don’t be afraid to mention this to your GP or optician, who should be familiar with CBS. You may find it useful to take a copy of this information along with you.