Visual snow syndrome
Persistent fine flickering dots across your entire field of vision — like static on an untuned TV — that don't go away.
Try Visual snow syndrome in the simulator →What it looks like
Visual snow looks like millions of tiny, fast-flickering dots layered over everything you see. It's present all the time, in light and dark, with eyes open or closed. Many patients also see afterimages or trails behind moving objects (palinopsia), tiny worm-like sparkles when looking at bright sky (blue-field entoptic phenomenon), halos around lights, and have heightened sensitivity to bright light. About 60–75% of people with visual snow also have constant ringing in their ears (tinnitus).
Clinical criteria (Schankin)
A diagnosis of visual snow syndrome requires visual snow for more than three months, plus at least two of: palinopsia (afterimages or trailing), enhanced entoptic phenomena (seeing your own eye floaters or blue-field sparkles), photophobia (light sensitivity), or nyctalopia (impaired night vision).
What causes it
Visual snow syndrome is a neurological condition, not an eye disease — eye exams come back normal. Brain imaging and EEG studies suggest hyperexcitability in visual processing areas. It often co-occurs with migraine and tinnitus.
When to see a doctor
Visual snow that has been present for years and is stable usually isn't dangerous, but you should see a neurologist or neuro-ophthalmologist for diagnosis. New onset of static-like vision, especially with headaches or other neurological symptoms, warrants prompt evaluation.
Also known as
VSS · TV static vision · Snow vision