The Grayish Blob in the Night: CBS, AMD, and Me
It first appeared weeks before my diagnosis with wet age-related macular degeneration (AMD). I’d see it when I would get up in the middle of the night, never during the day or outside after dark: a grayish, roundish blob in the center of my vision.
I wondered what it was but really didn’t focus on it. When I turned on a light, it would go away. Just weird.
I never thought to mention it to anyone
After my diagnosis, I simply assumed it had something to do with my AMD. Maybe it was the fuzzy thing that obscured the central vision of my "bad eye." Close my good eye and it was there. Close the bad one and it was gone.
I never thought to mention it to my retina specialist or anyone else, including my husband. No big deal, it was only there in the dark and disappeared when I turned on a light.
What Oliver Sacks says about hallucinations
It took 5 years and a casual decision to read a work by the late Oliver Sacks, a neurologist and the author of Awakenings for an answer. I wanted to read his book on music and the brain. It wasn’t on the Cloud Library, so I picked an alternate: Hallucinations.
According to Sacks, "Hallucinations don’t belong wholly to the insane. Much more commonly, they are linked to sensory deprivation, intoxication, illness, or injury." People with migraines often get them.1
What is Charles Bonnet syndrome?
In the first chapter of the book, I got the answer to my grayish blob, my ghost in the night. I was experiencing something called Charles Bonnet (bo-NAY) Syndrome (CBS). It is named after the Swiss doctor who first identified it.
According to the American Academy of Ophthalmology, "Charles Bonnet Syndrome (CBS) is a condition that some people get when they lose some or all their vision. It causes them to have visual hallucinations (seeing things that aren't really there).2
A deep dive into the literature revealed that CBS is not uncommon in people experiencing low vision. Sacks also mentions macular degeneration in his book. AMD is among the most common conditions associated with CBS; one study found that 12 percent of people with AMD will develop it.3
What is it like to experience CBS symptoms?
Sacks writes that Charles Bonnet syndrome is rather like the phantom pain people experience when they have had an arm or a leg amputated. This phantom vision comes with our loss of some of our vision.
Turns out that most people, like me, have these hallucinations when they wake up in the dark. What people see varies, but can include: repeating patterns of lines, dots, or other geometric shapes; landscapes, such as mountains or waterfalls; people, animals, or insects; people dressed in costume from an earlier time; and imaginary creatures, like dragons.2
The hallucinations may be move around or stay still, and they can be in color or in black and white. The length of time the hallucinations last can vary from seconds to hours.2
Ways to cope with CBS hallucinations
I have nothing exotic, just that grayish blob. Maybe I would be more concerned if it were people or landscapes. Or dragons.
There is no test for diagnosing CBS, and no cure. However, the American Academy of Ophthalmology does have some recommendations.2
First, accept that what you see is not really there. Second, talk about it with friends and doctors. Third, change your environment. I found that simply turning on a light gets rid of the Blob.2
Questions for my retina specialist
What I found most amazing is that no one has ever mentioned this as a side effect of macular degeneration. Believe me, it is the first thing I will ask about on the next visit to my retina specialist.
Thank you, Oliver Sacks... I still need to read his book on music and the brain.
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