People with Charles Bonnet syndrome (CBS) experience complex visual hallucinations that can seem very real. While there is no cure, people can take simple steps to reduce or sometimes stop their hallucinations.

People with CBS see visual hallucinations, which means they see things that are not really there. It affects up to 30% of people with visual impairment in both eyes.

This article explores Charles Bonnet syndrome, including its symptoms, causes, risk factors, and diagnosis. It also looks at treatments and remedies, possible complications without effective treatment, the outlook for a person with the condition, and frequently asked questions.

Side profile of Charles Bonnet who discovered the eye conditionShare on Pinterest
Kean Collection/Archive Photos/Getty Images

CBS gets its name from the 18th-century Swiss scientist Charles Bonnet, who observed the syndrome in his grandfather and later developed it himself.

This condition affects people with vision loss or other eye conditions. People with CBS see hallucinations because they have damage along their visual pathways, the connection from their eyes to their brain. They do not have any other form of hallucination, for example, hearing or smelling things that are not there.

CBS is not a mental health condition. It affects how a person’s brain processes visual images.

It can occur in people of any age, although it is more common in older people. Most are 74–84 years old when doctors diagnose it. Researchers do not know exactly how many people have CBS.

People with CBS see phantom images. These images can be simple lines, shapes, or more complex things such as people, animals, or faces.

These images are often clear, well-defined, and organized. A person with CBS has little or no control over their hallucinations.

People with CBS tend to see more than one type of hallucination. Those that involve people and faces are particularly common.

A person’s hallucinations may be:

  • still
  • moving
  • in color or black and white

Most people with CBS see hallucinations when they wake up. However, they can happen anytime.

People with CBS tend to find their hallucinations bizarre but not often disturbing.

Untreated CBS may impact a person’s mental health and cause stress. CBS hallucinations in older people are usually a sign they may have other conditions, such as:

Doctors do not yet know the cause of CBS hallucinations. Some researchers believe a person may experience CBS when they lose visual signals from their eyes to their brain. People may lose some or all of their vision in this way due to conditions such as:

Their visual system then does not process new images, leaving a gap where they would usually see things. A possible cause of CBS is that the brain may fill this gap by making up images or recalling stored ones for the person to see.

People are more at risk of developing CBS if they:

  • have a form of visual impairment or have lost their vision
  • are older
  • are socially isolated
  • spend a lot of time in dark environments

There is no single test to diagnose CBS. Instead, doctors will talk with a person about their medical history and rule out other causes of visual hallucinations. These could include:

  • mental health conditions
  • side effects from medications
  • neurological or brain conditions

CBS has no cure or specific treatment.

Doctors help people with CBS manage their hallucinations and try to make them last for less time. In most cases, a person’s hallucinations can become less frequent.


People may be able to manage CBS by:

  • Noting when their hallucinations happen and changing their environment in response: For example, if a person finds their hallucinations happen in brightly lit rooms, they can reduce the lighting. If they find their hallucinations occur when it’s very quiet, turning on a radio or TV may help.
  • Talking and being open about their CBS: It may help to talk with someone about hallucinations, such as a therapist, loved one, or friend. This can provide a person with support and encouragement to help deal with their CBS.
  • Having more social interactions: Social isolation is a risk factor for CBS. People may help reduce their hallucinations by engaging others in social interactions, in person or online.


Doctors normally only prescribe medication for people with severe, disturbing, or continuous CBS hallucinations.

Many of these medications may only have mixed or little effect. Some may only be effective for a small number of people. They can include:

  • low doses of antipsychotics such as quetiapine or olanzapine
  • cholinesterase inhibitors such as donepezil
  • antiepileptics such as valproate, carbamazepine, gabapentin, or clonazepam
  • antidepressants such as venlafaxine and escitalopram

Some eye exercises or movements can help reduce a person’s CBS hallucinations. A person can try:

  • rapidly moving their eyes from side to side during a hallucination while keeping their head still
  • looking away from the hallucinations
  • staring at the hallucinations
  • closing their eyes and opening them again during a hallucination
  • reaching out to touch their hallucinations

Regular sleep and exercise may help, as fatigue and stress can worsen hallucinations. Exercise and meditation may also reduce stress and anxiety, potentially leading to fewer hallucinations.

Research suggests that some people with CBS do not seek medical advice or tell others about their hallucinations due to a fear of being seen as mentally ill or receiving a mental health condition diagnosis.

Due to this, CBS may be more common than doctors think. However, people with CBS do not experience a decline in their mental health or faculties. People with CBS are psychologically typical.

While there is no cure for CBS, many people’s symptoms reduce over time.

Below are answers to some commonly asked questions about CBS.

What do people with CBS see?

What people with this syndrome see can vary. However, most see images of:

  • repeating patterns of lines, dots, or shapes
  • flashes of light
  • animals
  • insects
  • landscapes, such as waterfalls or mountains
  • flowers
  • people
  • buildings
  • people dressed in costumes from earlier times
  • imaginary creatures, such as dragons

How long does CBS last?

CBS hallucinations can last seconds, minutes, or hours. With treatment, they may stop after 1–2 years.

Is CBS life threatening?

CBS causes complex visual hallucinations. However, these do not affect brain health. The syndrome does not have any life threatening side effects or complications.

Is CBS connected to dementia?

People with CBS do not typically show signs of dementia. However, doctors can sometimes misdiagnose a person’s CBS as a sign of early dementia.

People with CBS have vivid and complex hallucinations that may make them think they have a mental health condition. For this reason, people with CBS often are reluctant to seek medical advice.

However, CBS does not affect a person’s mental faculties or health. Despite there being no cure for CBS, doctors can help people reduce their hallucinations.