Table 1.

International classification of headache disorders (ICHD-3) criteria for a diagnosis of visual snow syndrome.

A	Visual snow: dynamic, continuous, tiny dots across the entire visual field persisting for > 3 months
B	Additional visual symptoms of at least two of the following four types:
	i. Palinopsia. ii. Enhanced entoptic phenomena. iii. Photophobia iv. Nyctalopia (impaired night vision)
C	Symptoms are not consistent with typical migraine visual aura
D	Symptoms are not better accounted for by another disorder