Understanding Why Visual Snow Syndrome Is a Neurological Condition, Not a Retinal Disease
This systematic review examines Visual Snow Syndrome (VSS) as a potential network disorder of the brain. Patients with Visual Snow Syndrome experience continuous visual disturbances resembling static, along with additional symptoms such as afterimages (palinopsia), light sensitivity, night vision problems, and floaters. Non-visual symptoms like anxiety, depression, and cognitive difficulties are also common. The condition may affect up to about 2.2% of the population, often persists for years, and currently has no established treatment for Visual Snow Syndrome.
By analyzing 53 studies, the authors found that Visual Snow Syndrome is not caused by a single brain region but involves abnormal activity and connectivity across multiple brain areas, including the visual cortex (especially the lingual gyrus), thalamus, and large-scale networks such as the salience network and default mode network. Imaging and electrophysiological evidence suggests increased excitability in visual processing areas and disruptions in how the brain filters and prioritizes sensory input in Visual Snow Syndrome, leading to the perception of constant visual “noise.”
Overall, the review concludes that Visual Snow Syndrome is best understood as a disorder of brain network interactions, particularly involving impaired sensory filtering and overactivation of visual pathways. However, limitations in current research—such as small sample sizes and inconsistent diagnostic criteria—highlight the need for more rigorous studies to better understand Visual Snow Syndrome and develop effective treatments.
