Table 1.

Proposed criteria for visual snow syndrome [5••]

1	Visual snow: dynamic, continuous tiny dots in the entire visual field lasting longer than 3 months
2	Presence of at least two additional visual symptoms from the following: a) Palinopsia: afterimages or trailing of moving objects b) Photophobia c) Nyctalopia (impaired night vision) d) Other persistent positive visual phenomenon including (but not limited to) enhanced entoptic phenomena (excessive floaters or blue field entoptic phenomenon), kaleidoscope-type colours with eyes open or closed and spontaneous photopsias
3	Symptoms are not consistent with typical migraine visual aura
4	Symptoms are not better explained by another disorder