What’s Visual Snow Syndrome (VSS), And Why Do So Many Autistic People Have It?

What’s Visual Snow Syndrome (VSS), and why do so many autistic people have it?

I learned about this the other day, when I posted about palinopsia (visual trailing/afterimages) being common in autistic people, and a couple of our followers told me about their VSS. I did some more research, and discovered that I also have it.

Visual Snow Syndrome is a neurological condition that interferes with visual processing. It’s caused by hyperactivity and hyper-excitability of nerves in certain areas of the brain that process visual information.

The core feature of VSS is constantly seeing tiny, fuzzy “feedback” in the environment. It’s kind of like seeing the world through a staticky TV screen. Some people’s visual static is larger than others. Mine is relatively fine-grained, but it gets bigger and more obvious in low lighting.

Some of the other symptoms of VSS include:

Palinopsia (visual trailing/afterimages)

Photophobia (sensitivity to light)

Increased and enhanced ectopic phenomenon, such as floaters, phosphenes, and Scheerer’s phenomenon

Seeing glare, starbursts, and halos around lights

Difficulty seeing at night/in the dark

Seeing random flashes of light and/or color, without cause from the environment

It’s common for people with VSS to experience comorbid migraines, but VSS is not the same thing as migraine aura.

So, why do autistic people often have VSS?

It comes down to the fact that VSS is caused by the hyper-excitability of neurons in areas of the brain that process visual information. A core feature of autism is hyper-excitable neurons, especially in areas of the brain that have to do with sensory processing. So it makes sense that autism would often inadvertently cause VSS.

Here are some illustrations of visual phenomenon that VSS causes, in case you want a better understanding of what the world looks like for me and many other autistic people.

Visual snow/static: