Charles Bonnet Syndrome 1 (CBS) is a condition that can affect people with sight loss, causing them to see things that are not physically there (visual hallucinations). These hallucinations can present themselves from patterns to detailed images of people, animals or landscapes.
A key thing to note is that CBS is not a mental health condition 2, those who are experiencing CBS are very often aware that what they are seeing is not really there.
There are, at least, 1 million people in the UK who live with CBS. It is reported that up to half of all people with macular degeneration – a gradual loss of central vision – may experience CBS at some time.
CBS most frequently appears in people with significant vision loss, particularly from conditions such as age-related macular degeneration, glaucoma, or diabetic retinopathy.
Around 1 in 5 with sight loss develop CBS 3
Approximately 1 million adults in the UK have Charles Bonnet Syndrome as a secondary effect of blindness.
Causes of Charles Bonnet Syndrome
CBS happens as a result of reduced visual input to the brain. When sight is lost, the brain receives fewer signals from the eyes and may begin “filling in the gaps” by creating it’s own images that aren’t real. This process is occasionally compared to “phantom limb” sensations where the brain generates perceptions in the absence of real input. Although the exact cause is not fully understood, CBS is strongly linked to:
- Significant sight loss
- Sudden changes in vision
- Eye conditions affecting both eyes
Symptoms of Charles Bonnet Syndrome
While the most commonly reported symptom of Charles Bonnet Syndrome is hallucinations, other symptoms often include:
Moving or stagnant images
Patterns, shapes and moving lights
Faces, people, or animals
Colourful or black-and-white images
Landscape images
Hallucinations may last from from anywhere from a couple of moments to several hours and can come and go unpredictably. Lots of people who experience CBS report that these hallucinations are more likely to occur when they are feeling tired, relaxing or in a space with dim light.
Diagnosis of Charles Bonnet Syndrome
Sight loss itself can cause anxiety, fear and loneliness, but when CBS is added, the isolation can further worsen a person’s quality of life. Living in a world of unpredictable, uninvited images even if they are pleasant can impact negatively on everyday life.
Researchers have proved that isolation, stress, and fever can increase the number of CBS episodes a person may have and make the images more frightening. Judging surroundings and what is real and what is not, may become more difficult and caution is advised when moving or walking.
It is reported that medication taken for other conditions can also make CBS worse. It is therefore advisable for a GP to review all medication being taken by an individual dealing with CBS.
Treatment and management of Charles Bonnet Syndrome
There is currently no cure for Charles Bonnet Syndrome, but there are ways to manage symptoms. 4 For lots of people, the hallucinations can improve over time aSight loss itself can cause anxiety, fear and loneliness, but when CBS is added, the isolation can further worsen a person’s quality of life. Living in a world of unpredictable, uninvited images even if they are pleasant can impact negatively on everyday life.
Researchers have proved that isolation, stress, and fever can increase the number of CBS episodes a person may have and make the images more frightening. Judging surroundings and what is real and what is not, may become more difficult and caution is advised when moving or walking.
It is reported that medication taken for other conditions can also make CBS worse. It is therefore advisable for a GP to review all medication being taken by an individual dealing with CBS.s the brain adapts to vision loss. Understanding as much about the condition as possible itself be very reassuring and help reduce anxiety.
Common management strategies include:
Improving lighting conditions
Moving the eyes around or heavy blinking to disrupt hallucinations
Lowering stress levels and fatigue
Speaking to others about how you are feeling
Treating any underlying eye conditions where possible
Living with Charles Bonnet Syndrome
CBS can be distressing to live with, especially when symptoms first appear. But many people often find that:
- Hallucinations become less frequent over time
- They learn to recognise and manage episodes
- Support from professionals and charities can help
If hallucinations are increasingly distressing or on-going, it is important to seek guidance from an eye care professional or GP.
Saving sight through pioneering research
References and resources
1. Charles Bonnet Syndrome. NHS.
2. Charles Bonnet syndrome (CBS). Macular Society.
3. Prevalence of Charles Bonnet syndrome in low vision: a systematic review and meta-analysis. AES. 2022.
4. Charles Bonnet Syndrome (Visual Release Hallucinations). Cleveland Clinic. 2025.
