Charles Bonnet Syndrome

What is Charles Bonnet syndrome?

Charles Bonnet syndrome (pronounced “bo NAY”) is a condition that happens when a person with low vision has visual hallucinations.

The eye’s retina facilitates the conversion of light into a visual message for the brain. When you’re not able to do this, your vision gets worse and you become more likely to develop Charles Bonnet syndrome.

The hallucinations can be simple, like bright-colored patterns that show up over everything you see. The medical term for this is unformed hallucinations.

You can also see more complicated things, like animals, buildings or people that don’t exist. The medical term for this is formed hallucinations.

How does Charles Bonnet syndrome affect my body?

Although scientists aren’t quite sure of the pathophysiology behind Charles Bonnet syndrome, they think that the hallucinations happen because lower vision reduces the number of images your brain gets. Your brain wants more images, so it uses memories to recall things that it’s seen or simply makes things up.

This can be worrisome and confusing if you don’t know what’s happening.

Who does Charles Bonnet syndrome affect?

Charles Bonnet syndrome can affect people with conditions that cause vision loss, such as age-related macular degeneration (ARMD). One study indicated that more than 12% of people with ARMD will develop Charles Bonnet syndrome.

An estimated 1 in 2 people with severely impaired vision may develop hallucinations. Charles Bonnet syndrome can happen in anyone, but it’s more frequent in patients 80 years or older.

In addition to AMRD, other conditions related to developing Charles Bonnet syndrome include:

• Stroke.
• Cataracts.
• Glaucoma.
• Retinitis pigmentosa.
• Diabetes-related retinopathy.
• Optic neuritis.
• Giant cell arteritis.
• Eye removal.

What are the symptoms of Charles Bonnet syndrome?

The key symptom of Charles Bonnet syndrome is seeing hallucinations. These hallucinations may appear as:

• Patterns made up of lines or shapes that repeat. These images might look like bricks or nets.
• Imaginary animals like dragons or unicorns.
• Outdoor scenes, like waterfalls, trees or mountains.
• People’s faces, people, animals or bugs.
• People dressed as if they were living in the past.

The images may:

• Move or stay in one place.
• Be in color or be in black and white.
• Be true to size or be smaller than normal.
• Be pleasant or be scary.
• Be familiar to you or not familiar to you.
• Be the same each time they happen or change each time they happen.

These visions usually happen without noise. They can continue for various lengths of time from seconds to minutes to hours.

Most people with Charles Bonnet syndrome know that what they’re seeing isn’t real.

People with Charles Bonnet syndrome can’t control the hallucinations.

What causes Charles Bonnet syndrome?

The cause of Charles Bonnet syndrome is related to loss of vision. A main theory is that your brain wants images and isn’t getting enough, so it creates them.

Some studies have indicated that what you see suppresses some nerve activity in your brain. When your eyes aren’t supplying that type of suppression, nerve activity in the brain appears as visual hallucinations.

What are risk factors Charles Bonnet syndrome?

Risk factors for Charles Bonnet syndrome include:

• Being 80 years old or older.
• Having low vision.
• Being alone/socially isolated.
• Being in a dark environment.

What tests will be done to diagnose Charles Bonnet syndrome?

Your healthcare provider or eye care specialist will take your medical history, ask questions about your symptoms and do thorough physical and eye examinations.

It’s possible to have hallucinations when you’re taking certain medications. It’s also possible to have hallucinations if you’re withdrawing from using drugs or alcohol. You can also have hallucinations after cataract surgery.

Your providers will want to eliminate any other conditions that could possibly cause hallucinations, such as Alzheimer’s disease, Parkinson’s disease, Lewy body dementia and schizophrenia.

Your providers may recommend neurological tests to rule out these other diseases.

Can Charles Bonnet syndrome be cured?

There’s no cure for Charles Bonnet syndrome. Providers have tried medications but they didn’t work. Symptoms often improve with time, possibly because your brain becomes used to receiving fewer images to process. However, it may take years for the hallucinations to stop.

How can I manage symptoms of Charles Bonnet syndrome?

If you have Charles Bonnet syndrome, you may be able to manage symptoms better with the following tips.

Managing Charles Bonnet syndrome with eye movements

You may want to blink your eyes or close your eyes. You might want to look away from the hallucination or stare at it. You can also try moving your eyes without moving your head, looking from side to side or up and down.

Managing Charles Bonnet syndrome with improved lighting

You may find it easier to deal with Charles Bonnet syndrome if you have brighter light, especially in the evenings.

Managing Charles Bonnet syndrome by being less isolated

It may help you to spend less time alone and spend more time with people. The people you spend time with should be people you can talk to about your life, including the images you’re seeing. You may want to find a support group to improve your connections.

Managing Charles Bonnet syndrome with rest and relaxation

Some people have found that their symptoms get worse when they’re under stress or don’t get enough rest. Try to get enough sleep and to develop other ways to relax and to relieve stress. These could include practices like meditation, deep breathing and learning to relax your muscles in a progressive way.

In addition to these suggestions, your provider may suggest anti-anxiety medications or antidepressants to help you deal with your emotions and uncertainties.

How can I prevent Charles Bonnet syndrome?

Since researchers don’t really know what causes Charles Bonnet syndrome, there’s no concrete way to prevent it. You may be able to reduce your risk by taking certain steps to preserve your vision. For instance, if you havediabetes, you can do your best to manage your blood sugar levels.

It’s very important for everyone to have regular eye exams. This is especially true as people age, since many of the causes of vision loss happen as people get older.

It’s important to have a good relationship with your ophthalmologist or other eye care provider.

What can I expect if I have Charles Bonnet syndrome?

There’s no cure for Charles Bonnet syndrome. It may disappear over time, but it may take one to two years to go away.

You may find it difficult to do some of your daily tasks or walk in places that you don’t know well if you’re seeing things that aren’t there. It’s important to tell your healthcare provider about it.

What questions should I ask my healthcare team about Charles Bonnet syndrome?

You may have many questions for your providers about Charles Bonnet syndrome. Some of them may include:

• Are there certain tests you would recommend to determine if I actually do have Charles Bonnet syndrome?
• Can you recommend a support group for me?
• Would I benefit from being in a clinical trial?
• How can I deal with the condition that’s causing my vision loss?
• Can you suggest ways for me to deal with Charles Bonnet syndrome?

What is the difference between Charles Bonnet syndrome and Anton syndrome?

If you have Charles Bonnet syndrome, you see hallucinations and you know that they’re not real. If you have Anton syndrome, you can’t see but claim that you can. You tell people that you’re seeing things that you really aren’t seeing. You deny your blindness, which has often occurred after a cerebrovascular injury.

A note from Cleveland Clinic

You may be disturbed if you have low vision and you’re seeing things you know aren’t really there. You may have Charles Bonnet syndrome. You’ll want to discuss these images with your healthcare provider. They will be able to suggest some type of support group or other ways to deal with both your vision loss and the hallucinations. It’s very important to get a correct diagnosis of your condition so you can get the best treatment.