Visual snow is a persistent visual disturbance where individuals see tiny, flickering dots, similar to television static, across their entire field of vision. This recognized neurological disorder involves visual disturbances present regardless of lighting conditions. It is believed to originate from altered brain processing rather than an issue with the eyes themselves.
What Visual Snow Looks Like
The primary symptom of visual snow is the perception of countless small, dynamic dots across the entire visual field. These dots can resemble the static seen on an untuned analog television screen. The “snow” can vary, appearing black and white, transparent, or even colored and flashing. It is present whether the eyes are open or closed, distinguishing it from transient visual disturbances like typical floaters or temporary visual auras associated with migraines. Unlike migraine aura, which typically moves slowly and resolves, visual snow remains static and continuous.
Other Related Symptoms
Visual snow often occurs alongside other visual and non-visual symptoms, forming Visual Snow Syndrome. Individuals may experience tinnitus, a persistent ringing or buzzing sound in the ears. Photophobia, an increased sensitivity to light, and nyctalopia, or difficulty seeing at night, are also frequently reported.
The syndrome can also include palinopsia, where individuals see afterimages or trailing images of objects. Enhanced entoptic phenomena are common, meaning people perceive normal visual artifacts, such as floaters, with unusual vividness. Non-visual symptoms can include anxiety, depression, difficulty concentrating, or a feeling of brain fog.
Understanding Potential Causes
Visual Snow Syndrome is believed to be a brain disorder involving altered processing within various brain regions, particularly the visual cortex. Research suggests it stems from dysfunction in interconnected neural pathways, rather than a single localized brain region. One theory points to excessive excitability of neurons in certain brain areas.
Another hypothesis suggests that visual snow could be a form of thalamocortical dysrhythmia. This theory proposes that a failure of inhibitory action might prevent the brain from suppressing excitatory sensory information. The exact cause remains under investigation, but it is not linked to structural eye diseases or brain damage visible on standard imaging scans.
Diagnosis
Diagnosing visual snow is a clinical process, relying on an evaluation of a patient’s symptoms. There are currently no specific objective tests, such as blood tests or imaging, that can confirm the condition. The diagnostic procedure involves taking a medical history and conducting a neurological examination to rule out other conditions that might cause similar visual disturbances. These can include various eye diseases, side effects from certain medications, or other neurological disorders. Visual Snow Syndrome has been officially recognized as a distinct neurological disorder and, as of 2025, is included in the International Classification of Diseases, 11th Revision (ICD-11), under category 8A03.4.
Treatment Approaches
There is no universal “cure” for visual snow, but various strategies aim to manage symptoms and improve quality of life. Lifestyle adjustments, such as stress management and adequate sleep, can help alleviate symptoms. Neuro-optometric rehabilitation is a specialized approach that focuses on retraining the brain’s processing of visual information through targeted exercises. This may include eye-tracking and visual scanning activities to help the brain filter out the static.
Certain medications have shown some success, often by addressing co-occurring symptoms like migraines or anxiety. Lamotrigine and benzodiazepines have been noted to help manage visual snow symptoms. Specialized tinted lenses, FL-41 filters or blue light filters, can also offer relief by reducing light sensitivity and glare. Psychological support and coping mechanisms, including cognitive behavioral therapy, are also valuable components of managing the condition.