What is Visual Snow Syndrome (VSS)?
Visual Snow Syndrome (VSS) is a neurological condition that affects vision, hearing, cognition, sensory processing, and overall quality of life.
VSS is characterized by persistent visual disturbances, with the hallmark symptom being constant visual snow (VS) or static vision present in the visual field 24/7, regardless of whether the eyes are open or closed. In addition to visual snow, VSS is associated with other visual disturbances such as flickering dots, flashing lights, and afterimages. Beyond visual symptoms, VSS also includes a range of non-visual symptoms that affect sensory processing and cognitive functions, potentially further impacting quality of life.
VSS is classified as a network brain disorder, resulting from dysfunction in multiple interconnected regions responsible for processing vision and sensory information. This dysfunction involves hyperactivity in certain brain areas and reduced connectivity in others, disrupting the brain’s ability to properly process sensory input, which leads to the wide variety of visual and non-visual symptoms seen in VSS.
The severity of Visual Snow Syndrome can range from mild to profoundly debilitating, with an estimated 2-3% of the global population affected. VSS can be present from birth or develop spontaneously at any stage of life.
What Are the Symptoms of Visual Snow Syndrome?
The primary symptom of Visual Snow Syndrome (VSS) is the persistent experience of visual snow, often described as static, flickering dots, and flashing lights, visible 24/7, whether the eyes are open or closed. Individuals with VSS frequently compare it to trying to see through a snowstorm or a shaken snow globe. However, Visual Snow Syndrome encompasses much more than just visual disturbances.
Those affected also commonly experience a range of debilitating visual and non-visual symptoms, including palinopsia (afterimages), photophobia (light sensitivity), tinnitus (ringing in the ears), paresthesia (tingling or numbness), anxiety, depression, depression, depersonalization, and insomnia. The intensity and impact of these symptoms can vary from mild to moderate, and in many cases, can be life-altering, depending on the individual.
What Causes Visual Snow Syndrome?
Visual Snow Syndrome (VSS) is classified as a network brain disorder, arising from disruptions in the brain’s interconnected neural pathways rather than being localized to a single region. These neural networks play a crucial role in coordinating sensory, motor, and cognitive functions, and when dysregulated, they can lead to the diverse range of symptoms seen in VSS.
Network Dysfunction and Symptom Complexity
Research shows that VSS involves both overactive and underactive areas in the brain. For example, the visual cortex (especially the lingual gyrus) and the thalamus—key regions for processing and filtering sensory input—tend to be overly active. At the same time, other regions, such as the insula, show reduced activity. The insula helps the brain filter and prioritize sensory information, so when it’s less active, the brain can become overwhelmed by incoming signals.
Studies have also found higher levels of lactate—a marker of cellular stress and energy use—in the right lingual gyrus. Elevated lactate levels have been linked to weaker brain responses during visual stimulation, suggesting that the visual system is under metabolic strain.
Together, these findings indicate that VSS involves both disrupted sensory filtering and metabolic stress in visual brain regions. This helps explain why symptoms vary from person to person and why disruptions in these neural networks cause persistent visual disturbances, such as static, as well as non-visual symptoms like tinnitus, migraines, and sensory overload.
Potential Triggers and Onset
The exact cause of VSS remains undetermined, though numerous potential triggers for symptom onset have been identified. These include:
Certain medications, particularly those with serotonin reuptake inhibiting properties, as highlighted by clinical studies
Extreme physical or mental stress
Concussions or traumatic brain injuries (TBI)
Migraines, especially migraine with aura
Infectious diseases
Surgical procedures
The diversity of these potential triggers underscores the complexity of VSS, suggesting that it arises from a combination of genetic, neurological, and environmental factors.
Living with Visual Snow Syndrome
A Visual Snow Initiative x Tiny Studios Short Film
Visual Snow Syndrome Signs & Symptoms
Visual Snow Syndrome (VSS) can impact individuals of any age or background, presenting a range of both visual and non-visual symptoms.
Diagnostic Criteria Summary: Visual Snow Syndrome (VSS)
Visual Snow Syndrome (VSS) is diagnosed based on a combination of persistent visual phenomena and associated symptoms, in the absence of other identifiable causes. The core diagnostic criteria include:
Dynamic, continuous tiny dots across the entire visual field, persisting for more than three months
Additional visual symptoms of at least two of the following four types:
Palinopsia (persistent recurrence of a visual image and/or trailing images after the stimulus has been removed)
Enhanced entoptic phenomena*
Photophobia (sensitivity or intolerance of light, which can cause some people to avoid sunlight, computers, fluorescent lights, and car headlights)
Nyctalopia (impaired night vision)
Symptoms are not consistent with typical migraine visual aura
Symptoms are not better accounted for by another medical condition
*excessive floaters in both eyes, excessive blue field entoptic phenomenon (uncountable little grey/white/black dots or rings shooting over the visual field of both eyes when looking at homogeneous bright surfaces such as the blue sky), self-lighting of the eye (colored waves or clouds perceived when closing the eyes in the dark), and spontaneous photopsia (bright flashes of light)
Visual Symptoms of Visual Snow Syndrome
Visual snow (dynamic, snow-like dots across the entire visual field)
Palinopsia (continuing to see an image after the stimulus has been removed)
Photopsia (flashes of light or small floating objects)
Enhanced entoptic phenomena (excessive floaters and rings of light shooting across the entire visual field, more noticeable when looking at bright surfaces like the blue sky)
Photophobia (sensitivity or intolerance to light)
Nyctalopia (impaired night vision)
Diplopia (double vision)
Visual distortions
Susceptibility to sensory overload (when the brain receives more sensory input than it can handle, triggering a "fight-or-flight" response)
Hyperacusis (increased sensitivity to sounds, especially those at specific frequencies)
Phonophobia
Tremors (involuntary, rhythmic movements of the body)
Balance issues (difficulty maintaining body position or stability)
Dry eyes
Other visual phenomena, such as starbursts and halos
Tinnitus (ringing or buzzing sound in the ears)
Anxiety
Depression
Derealization
Depersonalization (feeling detached from yourself)
Frequent migraines
Brain fog and confusion
Dizziness
Nausea
Paresthesia (tingling "pins-and-needles" sensations, commonly experienced in the arms, hands, legs, and feet)
Insomnia and other sleep disturbances
Sensory disturbances (such as "brain zaps" or electric shock-like sensations)
Sensory hypersensitivity / hyperesthesia (increased sensitivity to stimuli, such as sights and sounds)
Cutaneous allodynia (pain sensation on the skin or scalp from non-painful stimuli, such as a hairbrush on the scalp or glasses on the nose/ears)
Non-Visual Symptoms of Visual Snow Syndrome
Visual Snow Syndrome (VSS) can impact individuals of any age or background, presenting a range of both visual and non-visual symptoms.
Tinnitus (ringing, buzzing, or humming sounds in the ears)
Depersonalization (a sense of detachment from oneself)
Derealization (a feeling that the external world is unreal or distorted)
Anxiety
Depression
Frequent migraines
Brain fog and confusion
Dizziness
Nausea
Insomnia and other sleep disturbances
Paresthesia (tingling "pins-and-needles" sensations, commonly in the arms, hands, legs, and feet)
Sensory disturbances (such as "brain zaps" or electric shock-like sensations)
Sensory hypersensitivity / hyperesthesia (increased sensitivity to stimuli, such as sights and sounds)
Susceptibility to sensory overload (when the brain receives more sensory input than it can process, triggering a "fight-or-flight" response)
Balance issues (difficulty maintaining body position or stability)
Tremors (involuntary, rhythmic movements of the body)
Cutaneous allodynia (painful sensation on the skin or scalp from innocuous stimuli, such as a hairbrush on the scalp or glasses on the nose or ears)
Hyperacusis (increased sensitivity to sounds, particularly those with certain frequencies)
Phonophobia
Dry eyes
Different Types of Visual Snow
Visual Snow (VS): The Hallmark Symptom of Visual Snow Syndrome (VSS)
Visual Snow (VS), or the constant presence of static in the visual field—visible with both eyes open and closed—is the hallmark symptom of Visual Snow Syndrome (VSS). While VSS encompasses a range of visual and non-visual symptoms, VS remains the defining characteristic of the condition. Experiencing VS is often compared to trying to see in the middle of a snowstorm or through a shaken snow globe, which is how the term “Visual Snow” came about.
The appearance of the static can vary from person to person, with differences in color, density, speed, size, and overall appearance. This variability contributes to the unique and individualized experience of VSS. Some may perceive fine, grainy static, while others might experience larger, denser particles or movement within the static.
Types of Visual Snow
The different types of Visual Snow individuals with VSS experience can differ significantly in terms of their characteristics, including:
Color Variations: Visual snow may appear in a variety of colors, such as white, black, or tinted hues.
Movement: The static may seem to move, oscillate, or shift at different speeds.
Density: The static may range from fine, almost imperceptible graininess to a dense and overwhelming disturbance.
Important Factors to Consider in Visual Snow Syndrome (VSS)
Visual Snow Syndrome (VSS) is a complex neurological condition that can vary widely from person to person. While the hallmark symptom of VSS is persistent visual static, the overall experience of the condition is influenced by a range of factors. These factors contribute to the severity, presentation, and impact of symptoms, affecting the quality of life for individuals with VSS.In addition to the core symptoms of visual disturbances, there are several important considerations that can shape the course of VSS, including medical history, the onset of symptoms, co-existing conditions, and the emotional and psychological effects of living with the condition. Understanding these variables is crucial for both healthcare providers and individuals managing VSS, as they offer insights into the diverse nature of the disorder and guide tailored treatment approaches.
Managing Visual Snow Syndrome (VSS)
Visual Snow Syndrome (VSS) presents uniquely in each individual, making personalized treatment plans essential for effective symptom management. To better understand the diverse ways VSS impacts individuals, visit our Types of Visual Snow page.While no known cure exists for VSS, various treatment options are available. Collaborating with Dr. Kelly, who is knowledgeable in VSS, is key to developing a personalized treatment strategy.
Neuro-Optometric Rehabilitation Therapy (NORT) for Visual Snow Syndrome
What is Neuro-Optometric Rehabilitation Therapy (NORT) for Visual Snow Syndrome (VSS)?Neuro-Optometric Rehabilitation Therapy (NORT) is a non-invasive, individualized therapeutic approach aimed at addressing visual deficits associated with various neurological and neuro-ophthalmological conditions, including Visual Snow Syndrome (VSS). The therapy focuses on retraining the brain’s visual processing mechanisms through the use of specialized lenses, prisms, filters, and targeted eye exercises. These interventions are tailored to each patient based on their specific symptoms and medical history.
In individuals with Visual Snow Syndrome, reducing strain on the visual system can help lower cortical hyperexcitability and overall neurological load. This facilitates more efficient visual processing and allows the brain to better adapt to incoming sensory input. By limiting unnecessary or competing visual stimuli, perceptual demand decreases, supporting neuroplastic mechanisms and potentially reducing the severity or frequency of additional visual disturbances.
Research indicates that individuals with VSS who undergo NORT may experience improvements in several areas, including:
Visual Disturbances: Reduction in symptoms such as visual snow, palinopsia (afterimages), and other related visual disturbances.
Eye Movement: Improvement in eye movement coordination and visual processing efficiency.
Mental Health: Decrease in anxiety, depression, and stress associated with visual disturbances.
Daily Functioning: Enhanced ability to perform activities like reading, driving, and other tasks requiring visual focus.
Quality of Life: Overall improvement in daily functioning, social interactions, and quality of life.