Crackling, fizzing, grey, black, and white specks flicking in and out of view like television static. Sound familiar? Turns out, you’re not alone. Visual Snow Syndrome is a rare and mysterious condition whose prevalence – and even existence – have been the topic of many scientific studies.
The visual anomaly is said to veil a person's vision with what appears to be TV static or “snow” which can be intermittent or constant in those affected. The visual snow may become more apparent in the dark or when your eyes are closed, so if you’ve ever found yourself wondering “why can I see static?” while trying to sleep, it could be worth reading on.
What is visual snow syndrome?
“Visual snow is a form of sensory disturbance in which an individual continuously perceives small dots throughout their visual field,” reads an article published in Nature. “This phenomenon was first described in 1995 but has only been characterized in detail in the past few years.”
For a long time, visual snow syndrome wasn’t taken seriously by many in the medical community. “When I first proposed it as a condition worth researching, colleagues thought I was completely, barking crazy,” said UK Visual Snow Syndrome expert Professor Peter Goadsby to Guardian.
Specializing in migraines as a director of the Wellcome Trust’s National Institute for Health Research, King’s College London, led Goadsby to the condition, owing to the similarities it shares with migraine aura.
Since then, he has co-authored a paper published in the journal Neurology, providing the first-ever clinical criteria for Visual Snow Syndrome. The study surveyed 1,104 patients with self-reported visual snow, and a diagnosis was confirmed in 1,061 people.
what are the symptoms of visual snow syndrome?
For a positive diagnosis, participants had to have the visual snow itself (“why can I see static” crew – this one’s for you!) plus at least two of the below symptoms:
- Extreme sensitivity to light
- Visual disturbances within the eye such as floaters
- Objects lingering in vision after looking away
- Poor vision in low light
Their results revealed that most cases of Visual Snow Syndrome kicked off in early life, with around 40 percent of those surveyed having it for as long as they could remember. Interestingly, there was a high incidence of migraine and tinnitus among those with more severe visual snow.
A second study (published in the European Journal of Neurology) springboarded off the back of The Internet, as members of an online community presented with bucket loads of information on the condition they believed themselves to have.
“It turned out that there is an entire community on the internet, consisting largely of people with self-diagnosed VSS,” explained lead researcher Daniel Kondziella to Nature. “Given the tremendous interest on social networks, I was wondering how frequent this syndrome was and how it had escaped medical attention until very recently.”
Kondziella and colleagues also carried out a survey, speaking to 1,015 people from the UK who were not aware of the study’s focus to avoid bias. The responses showed that 38 people exhibited symptoms consistent with visual snow, with 22 meeting the above criteria for Visual Snow Syndrome. That represents 3.7 and 2.2 percent respectively of the surveyed population.
Why can I see static?
At the time of writing, there’s no clear-cut cause for Visual Snow Syndrome, but it’s suspected that the phenomenon has origins within the brain as well as the eye. According to a review published in the journal Frontiers In Neurology, imaging showed changes in activity in certain parts of the brain among people who see visual snow.
Autoimmune disease, Lyme disease, and hallucinogenic drug use have also been run up the flagpole as potential triggers for Visual Snow Syndrome, but right now there isn’t any concrete proof of these theories.
All hope is not lost for the visual snow gang, however, as things are looking more positive on the research front. “The medical community are more supportive now than they were 10 years ago,” said Jennifer Ambrose of the Eye on Vision foundation which supports people with Visual Snow Syndrome. “The response is still: ‘There is nothing we can do for you,’ but it is a fair response, because there needs to be more research.”
You can find out more information about Visual Snow Syndrome from the Visual Snow Initiative.