https://www.verywellhealth.com/visual-snow-syndrome-1719607
For a diagnosis of Visual Snow Syndrome (VSS) you must have experienced the following:-
1. At least 3 of the below symptoms for over 3 months.
Floaters, the small shapes you may see in your visual field
Photopsia, the starbursts or flashes of light that may suggest a health issue
Nyctalopia, or impaired night vision
Kaleidoscope vision, the color swirls often seen with migraines
Palinopsia, or seeing something that isn't there anymore
Photophobia, a heightened or unusual light sensitivity
Non-Visual Symptoms
With visual snow syndrome, there may be other symptoms besides what you see. Symptoms that aren't visual include:
Migraines, a disabling headache often linked to visual migraine aura symptoms
Tinnitus, or ringing in the ears
Vertigo, a sense of spinning or dizziness, or balance loss
Fatigue, an unusual exhaustion often related to another health issue
Tremors, an uncontrollable motion in your body, often the hands
Anxiety, a mild to severe response to stress
Depression, a mood disorder associated with feelings of sadness and fatigue
2. No history of hallucinogenic drug use (LSD / Magic Mushrooms etc).
3. No physiological degeneration of your eye. An Optician or Ophthalmologist should be able to check this for you.