Clear vision versus disturbed vision People report seeing "snow", much like the<unk>  noise or "static" on a TV screen after transmission ends. In addition to this<unk> , many of those affected have other types of<unk>  disturbances such as starbursts, increased afterimages, floaters, trails, and many others.<unk>  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<unk>  symptoms. Diagnosis<unk>  syndrome is usually diagnosed with the following proposed criteria: *<unk> : dynamic, continuous, tiny dots in the entire<unk>  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<unk>  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 eye (phosphenes), or spontaneous photopsia. * iii. Photophobia. * iv. Nyctalopia; impaired night vision. * Symptoms are not consistent with typical migraine aura. * Symptoms are not better explained by another disorder (ophthalmological, drug abuse). * Normal ophthalmology tests (best-corrected<unk>  acuity, dilated fundus examination,<unk>  field, and electroretinogram); not caused by previous intake of psychotropic drugs. Additional and non<unk>  symptoms like tinnitus, ear pressure or brain fog and more might be present. It can also be diagnosed by PET scan. Comorbidities Migraine and migraine with aura are common comorbidities. However, comorbid migraine worsens some of the additional<unk>  symptoms and tinnitus seen in<unk> " syndrome. This might bias research studies by patients with migraine being more likely to offer study participation than those without migraine due to having more severe symptoms. In contrast to migraine, comorbidity of typical migraine aura does not appear to worsen symptoms. Psychological side effects of<unk>  can include depersonalization, derealization, depression, photophobia and heliophobia in the individual affected. Patients with<unk> " have normal equivalent input noise levels and contrast sensitivity. In a 2010 study, Raghaven et al. hypothesize that what the patients see as "snow" is eigengrau. This would also explain why many report more<unk>  in low light conditions: "The intrinsic dark noise of primate cones is equivalent to ~4000 absorbed photons per second at mean light levels; below this the cone signals are dominated by intrinsic noise".
Visual snow
Persistent aura without infarction
Instrument myopia
Aura (symptom)
Dental plaque
Pattern glare
Airsickness
Suberosis