Charles Bonnet syndrome (CBS) is common, under-recognized, and frequently misunderstood – by patients and clinicians alike. Characterized by visual hallucinations in people with visual impairment, CBS occurs without psychiatric illness or cognitive disorder, yet many patients experiencing CBS symptoms fear exactly that. A new clinical comment by University College London and King’s College London offers a timely solution: clear, structured guidelines for identifying and managing CBS in routine eye care services.
The authors emphasize that CBS spans a wide range of eye diseases associated with sight loss, with evidence suggesting it may affect as much as one in five patients attending low vision services.
The proposed mechanism is “release” or “de-afferentation”, where reduced visual input leads to heightened excitability in the visual cortex. Importantly, risk is noted to increase with more severe vision loss, but CBS can also occur even when acuity is relatively preserved – a reminder not to dismiss symptoms based on good vision.
A key clinical insight is that most patients won’t voluntarily disclose hallucinations unless asked directly, often due to fear of being labelled as mentally unwell. To counteract this reluctance, the authors recommend a simple, normalizing opener such as: “Some people with similar eye conditions occasionally see things that aren’t really there. Have you ever noticed anything like that?”
When hallucinations are reported, the guidance is to explore the details: onset, frequency, duration, triggers (including lighting, fatigue and stress), and – critically – the emotional impact of these visual disturbances.
Education is positioned as an important therapeutic intervention in its own right. Once reassured that CBS is a recognized, non-psychiatric consequence of visual loss, around 70% of patients report minimal distress. For those who remain distressed, the authors suggest behavioral and environmental strategies to reduce intensity or frequency of CBS symptoms: blinking, eye movements, distraction techniques, improving ambient lighting, and relaxation methods, such as mindfulness or breathing exercises.
For persistent negative-impact CBS, referral for psychological support (including CBT) is recommended, with psychiatry or neurology input where hallucinations are accompanied by significant anxiety, depression, or loss of insight.
The paper’s strength lies in its pragmatism – by embedding a straightforward, stigma-reducing CBS pathway into everyday consultations, ophthalmology teams can improve recognition, reduce distress, and provide consistent support for these patients.
The authors emphasize that CBS spans a wide range of eye diseases associated with sight loss, with evidence suggesting it may affect as much as one in five patients attending low vision services.
The proposed mechanism is “release” or “de-afferentation”, where reduced visual input leads to heightened excitability in the visual cortex. Importantly, risk is noted to increase with more severe vision loss, but CBS can also occur even when acuity is relatively preserved – a reminder not to dismiss symptoms based on good vision.
A key clinical insight is that most patients won’t voluntarily disclose hallucinations unless asked directly, often due to fear of being labelled as mentally unwell. To counteract this reluctance, the authors recommend a simple, normalizing opener such as: “Some people with similar eye conditions occasionally see things that aren’t really there. Have you ever noticed anything like that?”
When hallucinations are reported, the guidance is to explore the details: onset, frequency, duration, triggers (including lighting, fatigue and stress), and – critically – the emotional impact of these visual disturbances.
Education is positioned as an important therapeutic intervention in its own right. Once reassured that CBS is a recognized, non-psychiatric consequence of visual loss, around 70% of patients report minimal distress. For those who remain distressed, the authors suggest behavioral and environmental strategies to reduce intensity or frequency of CBS symptoms: blinking, eye movements, distraction techniques, improving ambient lighting, and relaxation methods, such as mindfulness or breathing exercises.
For persistent negative-impact CBS, referral for psychological support (including CBT) is recommended, with psychiatry or neurology input where hallucinations are accompanied by significant anxiety, depression, or loss of insight.
The paper’s strength lies in its pragmatism – by embedding a straightforward, stigma-reducing CBS pathway into everyday consultations, ophthalmology teams can improve recognition, reduce distress, and provide consistent support for these patients.