Apr 1, 2021

Diseases Spotlight: Charles Bonnet Syndrome

Charles Bonnet Syndrome (CBS) is a condition where a person with vision loss sees things that aren’t there (visual hallucinations). CBS is caused by the brain adjusting to significant vision loss and can be compared to phantom limb syndrome in someone who has lost a limb.

Visual hallucinations from CBS can appear as simple repeating patterns or more complicated images, including people or landscapes. Hallucinations can last for seconds, minutes or hours. The images can change how surroundings look making it difficult to get around, especially in new environments. While the hallucinations may be surprising, they are usually not scary. However, in the last year, during the pandemic, there is some evidence that individuals with CBS have experienced more frequent and disturbing hallucinations, learn more about the findings here. This increase is possibly triggered by increased anxiety and social isolation and reduced exercise. While for many people visual hallucinations go away after a year or two, for others they may last for years. There is no cure or specific treatment for CBS, although there are strategies individuals with CBS can use that may reduce their symptoms.

CBS is common in the vision loss community, especially for individuals with age-related vision loss such as age-related macular degeneration or glaucoma. However, it is often an overlooked condition. Many people with CBS do not talk about their experience because they may feel embarrassed or afraid that it is a sign of dementia or mental illness. As well, there is a gap in awareness of CBS among family doctors. One study showed that over 50% of surveyed family doctors in Canada were not aware of CBS, access this study.

Some strategies that may help relieve or reduce hallucinations are:

• Change the lighting conditions. Turn a light on or off.
• Change eye position. Move eyes side to side or up and down.
• Change environment. Move around or perform a simple task.
• Get enough sleep. Hallucinations may get worse if tired or stressed.

It can also help to talk with friends, family, or a health professional, such as a family or eye doctor or mental health professional. If the hallucinations are very upsetting or are strongly affecting day-to-day life, consider consulting a mental health professional or vision rehabilitation specialist.

If you have questions about CBS or your eye health, connect with FBC’s Health Information Line at 1.888.626.2995 or by email healthinfo@fightingblindness.ca