Hallucinations may result from vision loss

Keith Roach

Dear Dr. Roach: When I lost the vision in my eye in an accident, I had Charles Bonnet syndrome hallucinations. I am 80, and I went completely blind in one eye the day of the accident. There were patterns I saw whenever my eye was unfocused, which pretty much obscured everything. I saw complicated figures like very bright TV. I have read Oliver Sacks’ explanation in his latest book, called “Hallucinations.” What I viewed is exactly what he described.

Seven months later, I am still having hallucinations, but they are much subdued and not very interesting. I think it is gradually disappearing. What concerns me is none of the hospital personnel knew of the syndrome. I imagine there are a lot of old blind folks who think they are crazy, with no one to tell them otherwise.

I am hoping you might write an explanation for us who have failing eyesight and no explanation for what ails us. I had so many interesting visions, and since I knew it was not real, I rather enjoyed it.

L.R.

Dear L.R.: I can’t criticize the doctors at your hospital too much since I had never heard about this type of hallucination before your letter. In fact, a brief survey of some colleagues, with hundreds of years’ worth of clinical experience, showed me that many of us, unlike Dr. Sacks, had never heard of this syndrome, so I am glad to be able to bring it up.

Charles Bonnet syndrome, also called visual release hallucinations, occur in people who are losing or have lost vision. It seems to be more common in the elderly, but it has been reported in kids. Most who have had these hallucinations do not bring it up to their doctor, probably because they fear being labeled as having a psychiatric disease. It’s thought to happen due to the firing of nerve cells in areas of the brain that process vision when they are deprived of visual input from the optic nerve.

There are treatments available, including moving eyes rapidly back and forth, which often can stop the hallucinations if they are bothersome. There are also medications to stop them in people who don’t enjoy them the way you have.

Dear Dr. Roach: Have you ever heard of someone with sleep apnea outgrowing the need of a breathing aid?

G.S.

Dear G.S.: Most cases of sleep apnea are due to obstruction of the airway, caused by the relaxation of muscles in the back of the throat. Excess weight and obesity are the major risk factors for sleep apnea, but it can happen in normal-weight people. .

In nearly every case of obstructive sleep apnea getting better without a specific treatment I have seen, it has been associated with significant weight loss. It doesn’t have to be extreme weight loss. Since alcohol can make sleep apnea worse, stopping alcohol occasionally is enough to get sleep apnea under control.

Email questions to ToYourGoodHealth@med.cornell.edu.