Specialty Vision · Vision Simulator
Charles Bonnet Syndrome Simulator — Visual Hallucinations with Vision Loss
Some people with significant vision loss see formed images — patterns, flowers, figures or faces — that aren't really there. This is a known, harmless brain response, not a sign of mental illness.
Overview
Charles Bonnet syndrome (CBS) describes complex, formed visual images that some people notice after significant vision loss, seen with the eyes open while fully awake. The images are silent and don't interact with the viewer — they don't speak, respond, or react to anything you do. The leading explanation is a 'release' phenomenon: when the eyes send less visual information than usual, the visual part of the brain can generate its own patterns and shapes to fill the gap, similar in concept to how a phantom limb can still 'feel' present after an amputation. Many people who experience this worry, understandably, that something is wrong with their mind. It usually is not — CBS is a recognised, benign consequence of reduced visual input, not a psychiatric illness and not a sign of dementia.
Symptoms
- Repeating geometric patterns, lattices, or tiling shapes
- Flowers or other repeating decorative motifs
- Simple figures or schematic faces
- Images that are silent and don't interact with you or respond to what you do
- Episodes reported more often in bright, quiet surroundings than in dim or busy ones
- Episodes that typically last from seconds up to a couple of minutes
Causes
- Significant vision loss from an eye condition (most commonly age-related macular degeneration, glaucoma, or diabetic retinopathy)
- Reduced visual input is thought to let the visual cortex generate its own imagery — a 'release' phenomenon, not a mental-health condition
- Can occur across a range of vision-loss severity, not only in the most advanced cases
Treatment
There is no specific cure, because Charles Bonnet syndrome is not a disease in itself — it's a byproduct of vision loss. Simply understanding what it is brings most people real relief and reduces distress. Practical steps some people find helpful include changing the lighting in a room, blinking, briefly moving the eyes, or looking away and back again, which can interrupt an episode. Treating any underlying eye condition, and ruling out other causes with an eye doctor, are the main clinical steps.
When to see an eye doctor
Mention any unusual images you're seeing to your eye doctor or primary care doctor on a routine basis — not because it's an emergency, but so they can confirm there isn't another cause, offer reassurance, and help if the images become distressing. Insight that the images aren't real is usually present, though it can take a little time to develop, especially around the first episode — that's a normal part of how this condition is usually experienced, not a cause for alarm.
Seek urgent care for:
- Sudden vision loss alongside new visual images
- Confusion, memory changes, or other neurological symptoms alongside the images
- Visual images accompanied by other hallucinations (sounds, smells, touch) — CBS involves sight only
Frequently asked questions
Am I losing my mind?
No. Charles Bonnet syndrome is a well-recognised, benign consequence of vision loss, not a psychiatric illness and not a sign of dementia. It happens because the visual part of the brain can generate its own imagery when it receives less input than usual from the eyes.
Will I always know the images aren't real?
Most people do recognise that the images aren't real, though that awareness sometimes takes a little time to develop rather than being immediate — this is especially true around the first episode. This is a normal part of the experience and doesn't mean anything is wrong.
Why do the images happen more in bright rooms?
Episodes are reported more often in bright, quiet surroundings than in dim or busy ones, though the exact reason isn't fully settled. It's the opposite of what many people expect.
Do the images ever talk or respond to me?
No — a defining feature of Charles Bonnet syndrome is that the images are silent and don't interact with you. If voices, sounds, or other senses are involved, that points to something different and is worth discussing with a doctor.
How common is this?
Estimates suggest roughly 10-30% of people with significant vision loss experience it at some point, though many never mention it to anyone out of fear of being misunderstood — which is exactly why raising it with your eye doctor is worthwhile.
Sources
- Epidemiology and phenomenology of Charles Bonnet syndrome in low-vision patients — PMC (National Library of Medicine)
- Charles Bonnet Syndrome: When Visual Loss Conjures Mischief — American Academy of Ophthalmology (EyeNet)
- Charles Bonnet Syndrome (Visual Release Hallucinations) — Cleveland Clinic