Charles Bonnet Syndrome

Charles Bonnet syndrome causes visual hallucinations in people who have lost a significant amount of sight, despite otherwise good mental health.

Common symptoms

Seeing patterns, shapes, figures, faces, or scenes that are not really there, usually with full awareness that the images are not real.

Description

Charles Bonnet syndrome (CBS) affects some people who have lost a significant amount of sight from conditions such as macular degeneration, glaucoma, diabetic eye disease, or stroke. The brain, receiving less input from the eyes, can create its own imagery — from simple patterns to detailed scenes or figures.

The hallucinations are purely visual. People usually know or soon realise that what they are seeing is not real, and CBS is not a sign of mental illness or dementia.

There is no specific treatment, but understanding the condition can be very reassuring. Strategies such as changing lighting, looking away or blinking, and talking to a trusted professional or support organisation can all help reduce the impact.