Charles Bonnet Syndrome: A Care Staff Guide to Visual Hallucinations

Imagine a resident who tells you, calmly, that there are small figures in period costume walking across the lounge carpet. Many staff would suspect dementia or psychosis. For some people, the real explanation is Charles Bonnet syndrome, a condition in which people with sight loss see things that are not there. Knowing the difference protects people from wrongly being labelled, and from unnecessary medication.

What is Charles Bonnet syndrome?

According to NHS patient information from Manchester, Charles Bonnet syndrome is when people with sight problems have visual hallucinations and know that what they are seeing is not real. The hallucinations may be simple patterns such as mosaics or brickwork, or more detailed scenes with people, animals or buildings. They can last a few minutes or several hours. The Brain Charity describes them as silent and often vivid, and explains the leading theory: when the brain receives less visual input from the eyes, it can start to generate images of its own.

The person with Charles Bonnet syndrome usually has preserved insight. They are not hearing voices, they are not paranoid, and they are not confused about where they are. This is the single most useful distinguishing feature for staff.

Who is affected?

The condition is linked to eye conditions such as age-related macular degeneration and cataracts. Sight Support West notes that it is more likely when sight loss is sudden and when both eyes are affected. The Brain Charity adds that other conditions affecting the visual system, including stroke, diabetes and multiple sclerosis, can also be involved. It is not caused by mental illness or dementia. Many people never mention what they see because they fear they will be thought to be losing their mind, so staff should ask gently and without judgement.

How it differs from dementia and psychosis

Visual hallucinations can also occur in other conditions, so assessment matters. Our guide to Lewy body dementia explains that visual hallucinations are an important feature of that condition, but there they usually come alongside fluctuating attention, sleep problems and movement symptoms. In psychosis, hallucinations may be accompanied by delusions, disorganised thinking and loss of insight.

Sudden onset hallucinations, new confusion, drowsiness or agitation may signal delirium, infection or a medication problem, and need prompt medical attention rather than reassurance alone. If you are unsure, do not diagnose. Record what the person describes, when it happens, how they react and what their eyesight is like, and ask the GP or an eye clinic to review.

How to respond in the moment

• Stay calm and acknowledge the experience. Do not tell the person they are imagining things or arguing about whether it is real. Ask what they can see and how it makes them feel.
• Offer reassurance. Explain that it can happen when sight is poor, that it is not a sign of madness, and that many others have the same experience.
• Change the setting. Sight Support West and the Manchester guidance both suggest adjusting lighting.
• Try eye movement or closing the eyes. Looking from side to side, or briefly closing the eyes, can make some images fade.
• Redirect attention. Conversation, music or a favourite activity can help, as can gentle exercise.

Longer-term support

There is no cure, and the hallucinations may fade over time. The Manchester leaflet advises people to see their GP if the experiences are distressing. Sight Support West recommends an urgent GP appointment or NHS 111 if hallucinations begin, so that other causes can be considered. Make sure the person has had a recent eye examination, that any treatable eye condition is being managed, and that their glasses are clean and correctly prescribed.

Support is available from organisations such as RNIB, the Macular Society, Henshaws and the Partially Sighted Society, which offer helplines and peer support. Our guide to supporting people with visual impairment covers wider environmental adjustments, such as lighting and contrast, that can help both daily living and hallucinations.

Recording and care planning

Add the diagnosis, if confirmed, to the care plan, along with the person's own words about what they see and the strategies that help them. This prevents repeated alarm, avoids unnecessary referrals to mental health services, and ensures that agency or night staff respond consistently. Reassess if the content of the hallucinations changes, if they become frightening, or if the person loses insight.

Supporting staff understanding

Charles Bonnet syndrome is a good example of why training matters. A short briefing at team meetings, using real examples, helps staff respond with curiosity rather than alarm. If your team would benefit from structured learning on this and related topics, browse Learnsignal's CPD courses for care and healthcare staff.

Frequently asked questions

Does Charles Bonnet syndrome mean the person has dementia? No. According to Sight Support West and the Manchester NHS leaflet, it is not caused by dementia or mental health problems, and people usually know the hallucinations are not real.

Should we give medication? There is no cure, and the guidance above focuses on reassurance, lighting, eye movement and distraction. Any medication question should go to the prescriber.

Who should we tell? Inform the GP, record it in the care plan, and consider referral to eye services and sight loss charities.