Charles Bonnet Q&A

Illustration of a Charles Bonnet hallucination and strange faces in an alley way

As part of our Charles Bonnet campaign, Dr John-Paul Taylor, Clinical Senior Lecturer and Consultant from the Newcastle University took part in a live Twitter question and answer session.

If you were unable to join the session, please find the full Q&A session below.

1. What causes visual hallucinations to occur?

Loss of vision mean brain cells firing more, which means more hallucinations. So if ++ firing in the “faces” part of the brain you see faces.

2. What are the most common hallucinations?

Two main types - simple hallucinations e.g. lines, geometric shapes etc. & complex hallucinations animals children people landscapes.

3. Do more people see nice hallucinations than they do scary hallucinations?

Probably about a third of people with CBS experience distressing hallucinations.

Sometimes it isn't the fact that they are scary. Rather they are disruptive to daily life - how to avoid that wall that appeared!

4. My hallucinations have been in finite detail. Is it random or related to the concept of genetic memory I often wonder?

In the main hallucinations vary considerably between people with #CBS in terms of what they see, when in course of eye disease they see it.

5. If sight is restored, through cataract surgery, retina re-attachment etc, is CBS likely to disappear?

Very good question! Improving visual function may help lower the brain cell over-activity for some. #CBS

6. Why do some people like me only see shapes and patterns etc while others see more "conrete" images like people and animals?

The million dollar question! A loss of visual input seems to overdrive the brain into creating its own phantoms. #CBS

We think it is to do with where the over-activity is. Simple hallucinations may occur lower down in visual system. Complex visual hallucinations = higher up #CBS

7. What's the incidence of Charles Bonnet Syndrome among people with advanced AMD?

Probably at least a third. We are doing studies to find out more as many people don't let on they have hallucinations. #CBS

8. How can health professionals help raise awareness of Charles Bonnet Syndrome?

Health professionals themselves need to be more aware of the condition. There is currently a lack of understanding out there.

Asking every person with eye disease whether they get hallucinations or not helps.

9. Why are so many doctors and specialists so reluctant to discuss CBS with patients?

This is a problem. We know talking about CBS can reduce the negative impact of the hallucinations long term for people with #CBS.

10. Apart from sight loss, are there other causes of visual hallucinations?

Yes many causes. Dementia, epilepsy, migraines, stroke to name but a few.

11. And how can these differ from hallucinations experienced by people with sight loss?

Migraines are simple hallucinations. Dementia are most typically complex hallucinations. Epilepsy are often hallucinations in other domains, when I say other domains e.g. hearing things, smelling things etc.

Hallucinations can also occur in people with schizophrenia and bipolar. Lewy body dementia complex visual hallucinations are very common.

12. Is there anything that can reduce the frequency of hallucinations?  

Hallucinations may decrease for some over time. Other techniques such as eye movements can help others.

Move your eyes from left to right. Do this every second 15 times without moving your head, then pause for a few seconds and repeat.

Also sometimes staring at image and blinking rapidly / reaching out to touch the vision may help abate the hallucinations.#CBS