Visual snow syndrome (VSS) is an uncommon neurological condition in which the primary symptom is that affected individuals see persistent flickering white, black, transparent, or coloured dots across the whole visual field. Other common symptoms are palinopsia, enhanced entoptic phenomena, photophobia, insomnia, and headaches. The condition is typically always present and has no known cure, as viable treatments are still under research. Migraine and tinnitus are common comorbidities and are both associated with a more severe presentation of the syndrome. The cause of the syndrome is unclear. The underlying mechanism is believed to involve excessive excitability of neurons in the right lingual gyrus and left anterior lobe of cerebellum. Another hypothesis proposes that visual snow syndrome could be a type of thalamocortical dysrhythmia and may involve the thalamic reticular nucleus (TRN). A failure of inhibitory action from the TRN to the thalamus may be the underlying cause for inability to suppress excitatory sensory information. Research has been limited due to issues of case identification and diagnosis, the latter now largely addressed, and the limited size of any studied cohort. Initial functional brain imaging research suggests visual snow is a brain disorder. There is no established treatment for visual snow syndrome. Medications that may be used to treat the condition include lamotrigine, acetazolamide, or verapamil. However, in absence of a secondary pharmaceutical indication, these do not necessarily result in benefits, and the evidence for their use is limited. Signs and symptoms In addition to visual snow, many of those affected have other types of visual disturbances such as starbursts, increased afterimages, floaters, trails, and many others. Visual snow likely represents a clinical continuum, with different degrees of severity. The presence of comorbidities such as migraine and tinnitus is associated with a more severe presentation of the visual symptoms. Diagnosis Visual snow syndrome is usually diagnosed with the following proposed criteria: Visual snow: dynamic, continuous, tiny dots in the entire visual field lasting more than three months. The dots are usually black/gray on a white background and gray/white on a black background; however, they can also be transparent, white flashing, or colored. Presence of at least 2 additional visual symptoms of the 4 following categories: i. Palinopsia. At least 1 of the following: afterimages or trailing of moving objects. ii. Enhanced entoptic phenomena. At least 1 of the following: excessive floaters in both eyes, excessive blue field entoptic phenomenon, self-light of the