Charles Bonnet Syndrome (CBS): Understanding Visual Hallucinations

Charles Bonnet Syndrome (CBS)

Also called visual release hallucinations. Occurs in people with significant vision loss who experience vivid, detailed visual hallucinations they recognize as unreal.

Causes

• Significant vision loss: macular degeneration, glaucoma, optic nerve atrophy, diabetic retinopathy.
• More common with longer-standing, advanced vision loss.
• Brain compensates for lack of visual input; possible over-activity of visual pathways.
• Risk factors: elderly, long-term vision loss, low-light environments, anxiety/depression/sleep disturbance.

Symptoms

• Hallucinations: simple (geometric patterns, flashes) or complex (people, animals, scenes).
• Intermittent or continuous; often in low light.
• Usually not distressing; recognized as unreal.
• May include multiple types simultaneously.
• Rarely: auditory/tactile hallucinations.

Management

• No specific cure; reassurance and education often suffice.
• Treat underlying vision loss.
• Manage anxiety/depression if present (medications may help).
• Vision rehabilitation may reduce frequency.