Charles Bonnet Syndrome (phantom vision)

Last updated: May 27, 2016

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Here are two informative articles about phantom vision, which affects between 10 and 40 percent of people with low vision.

The first article comes from an article in the Lighthouse International's Sharing Solutions newsletter, February 2004, on page 5: "I See Purple Flowers Everywhere: The Many Visions of Charles Bonnet Syndrome" (182 Kb .pdf) by Lylas G.Mogk,MD, and Marja Mogk, PhD; with Carol J. Sussman-Skalka,CSW, MBA.

Do you ever see things you know are not there but look real anyway? It's a common side effect among people with vision impairment. While we refer to it as "phantom vision," the technical term is "Charles Bonnet Syndrome." If you've experienced this, rest easy. Your mind is fine. It's your eyes that are playing tricks on you.

What Exactly Is Charles Bonnet Syndrome?

Charles Bonnet, an 18th century Swiss naturalist and philosopher, is credited as the first person to describe the syndrome. Like his grandfather, who had low vision and saw men, women, birds and buildings he knew were not there, Charles experienced similar phantom visions when his own vision deteriorated.

One explanation compares this condition to phantom limb experiences. People who have a limb amputated may still feel their toes or fingers, or may experience itching on an arm that is not there. This happens because the limb's nerves are still active and sending signals to the brain, which the brain interprets as sensations from the missing limb. Similarly, when retinal cells become impaired and are no longer able to receive and relay visual images to the brain, the visual system begins firing off images on its own.

Often, these images are not related at all to a person's life. Sam, who has macular degeneration, said, "I see little monkeys with red hats and blue coats playing in the front yard." Sam had no doubt that the monkeys he saw were not real ones. As a result, he wasn't concerned about his mind. However, he was worried about what others would think, so he kept it to himself…

Lighthouse.org—Home > About Us > Newsletters and Publications > Sharing Solutions > Fall 2004 > Purple Flowers

The article continues on to explain the percentage of people who may be affected by Charles Bonnet Syndrome and that it is not a psychiatric problem. The article describes some of the images seen that patients have reported.

A majority of people do not find their phantom vision disturbing, probably because the images they see are amusing, pleasing or entertaining.…

This article is based on, and includes quotes from, a chapter in Macular Degeneration: The Complete Guide to Saving and Maximizing Your Sight, written by Lylas G. Mogk, MD, and Marja Mogk, PhD, published by The Ballantine Publishing Group (2003).

This article appeared in Sharing Solutions – Fall 2004 Edition


The second article describing Charles Bonnet Syndrome comes from "Flashes and Paisley Prints" by Kate Chamberlin. Kate’s personal blog documents her "life and times as a writer who happens to be blind". Kate also experienced hallucinations during the 1980s while she was going blind.

For more of Kate's writing, see Kate's Blog at http://katechamberlin.com/.