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Visual snow syndrome

Visual snow syndrome (VSS) is a rare neurological disorder characterized by the persistent perception of tiny, flickering dots—often likened to television static or "visual snow"—across the entire visual field in both eyes, accompanied by additional visual and non-visual symptoms.^[1] This condition, first formally described in the early 1990s but increasingly recognized since the 2010s, affects approximately 2% of the population and is classified as a positive visual phenomenon originating from cortical hyperexcitability rather than ocular pathology.^[2]^[3] The core symptom, visual snow, manifests as continuous, dynamic dots that patients describe as moving or shimmering, present constantly regardless of lighting conditions and worsening in low light or against plain backgrounds.^[4] Additional visual symptoms commonly include palinopsia (trailing or afterimages of moving objects), photophobia (light sensitivity), nyctalopia (impaired night vision), and entoptic phenomena such as heightened perception of floaters or blue field entoptic phenomenon.^[5] Non-visual symptoms often accompany these, such as tinnitus, migraine (with VSS present in up to 70% of cases), anxiety, depression, and sensory sensitivities, suggesting a broader cortical network dysfunction.^[4]^[6] Diagnosis relies on clinical history and exclusion of other causes via neuroimaging and ophthalmologic exams, with proposed criteria requiring the snow to be present for at least three months and not attributable to substances or other disorders.^[7] The pathophysiology of VSS remains incompletely understood but involves aberrant hyperactivity in the visual cortex and thalamocortical networks, as evidenced by functional MRI studies showing altered connectivity and reduced GABAergic inhibition.^[8] It frequently emerges in young adulthood, sometimes triggered by migraine onset, head trauma, or infections, though many cases are idiopathic.^[2] There is no curative treatment, but management focuses on symptom relief through tinted lenses (e.g., FL-41 filters), medications like lamotrigine or topiramate for cortical stabilization, and visual rehabilitation therapies to mitigate perceptual overload.^[1] Ongoing research emphasizes its links to migraine and persistent perceptual disorders, highlighting the need for multidisciplinary approaches in neurology and ophthalmology.^[9]

Overview and definition

Visual snow phenomenon

Visual snow is a persistent visual disturbance characterized by the perception of numerous tiny, dynamic flickering dots resembling static noise, distributed uniformly across the entire visual field in both eyes and present continuously while awake.^[10]^[11]^[12] These dots are typically described as small, mobile, and asynchronous, often appearing white, translucent, or colored, akin to the visual noise seen on a detuned analog television or digital salt-and-pepper interference.^[13]^[10] The density and prominence of the snow can vary with lighting conditions, becoming more noticeable in darker environments or against uniform backgrounds.^[10]^[14] This phenomenon is not caused by ocular pathology or external factors such as medications, retinal disorders, or environmental influences; instead, it arises from central nervous system processing abnormalities.^[15]^[5] Onset typically occurs in early adulthood, though it can manifest at any age, including childhood or later in life, and persists lifelong without spontaneous resolution in most cases.^[5]^[16]^[17] The visual snow phenomenon was first systematically reported in 1995 by Liu et al., who described a series of migraine patients experiencing ongoing positive visual phenomena resembling television static.^[18]^[5] It received formal recognition and nomenclature as "visual snow" in 2014 through the work of Schankin et al., who delineated it as a distinct neurological entity separate from persistent migraine aura.^[19] While visual snow represents the hallmark feature, the broader visual snow syndrome encompasses additional symptoms beyond this isolated disturbance.^[3]

Syndrome diagnostic criteria

The diagnostic criteria for visual snow syndrome (VSS) were first formally proposed in 2014 to distinguish it as a distinct neurological disorder, requiring the persistent presence of visual snow as the core symptom, accompanied by additional specific visual disturbances. These criteria mandate dynamic, continuous visual snow—described as innumerable tiny flickering dots across the entire visual field—lasting for more than three months, plus at least two of the following: palinopsia (including afterimages or trailing), enhanced entoptic phenomena (such as floaters, self-light of the eye, or spontaneous photopsia), photophobia, or impaired night vision (nyctalopia). The symptoms must cause significant distress or impairment in daily functioning and cannot be better accounted for by another ocular, neurological, or psychiatric condition. Exclusion criteria are essential to rule out mimickers, particularly substance- or medication-induced causes. VSS diagnosis requires that symptoms are not attributable to hallucinogen persisting perception disorder (HPPD), which shares visual features but stems from prior hallucinogen use, nor to other perceptual disturbances like persistent migraine aura without the full VSS profile. Additionally, routine ophthalmological and neurological evaluations, including normal fundus examination and visual acuity, are implied to exclude structural or alternative pathologies. Non-visual symptoms, such as tinnitus (occurring in approximately 60-70% of cases), play a supportive role in the clinical picture but are not required for diagnosis.^[12] In December 2024, visual snow syndrome was assigned the ICD-11 code 9C4Y, recognizing it as a specified disorder of the visual pathways or centers.^[20] These criteria highlight VSS as a cortical hyperexcitability disorder, reinforcing the need for symptoms to be chronic and debilitating without alternative explanations, and encourage inclusion of associated features like depersonalization or sensory sensitivities in comprehensive phenotyping, though they do not alter the mandatory visual thresholds.^[17]

Signs and symptoms

Primary visual symptoms

The primary visual symptoms of visual snow syndrome extend beyond the core visual snow phenomenon and encompass a range of persistent perceptual disturbances that affect the entire visual field. These symptoms are obligatory for diagnosis when combined with visual snow and at least two additional symptoms from the specified criteria, forming the basis of the condition's clinical presentation. They contribute to significant visual overload and impaired daily functioning, often described by patients as constant and unremitting. Palinopsia, reported in approximately 80% of patients, involves the abnormal persistence or recurrence of visual images after the stimulus has ceased. It includes static palinopsia, where afterimages linger from stationary objects, and dynamic palinopsia, characterized by trailing or streaking behind moving objects, such as when following a car or finger. This symptom arises from altered visual processing rather than ocular pathology and is distinct from typical afterimages in healthy individuals.^[21] Enhanced entoptic phenomena, observed in approximately 65% of cases, refer to heightened awareness of normal internal ocular structures and processes. Common manifestations include increased perception of floaters (opaque specks drifting in the visual field), the blue field entoptic phenomenon (tiny bright dots moving rapidly against a bright blue background, akin to leukocytes in retinal capillaries), spontaneous photopsia (unprovoked flashes or sparkles of light), and self-light of the eye (perception of faint glows or patterns originating from within the eye itself). These phenomena, usually subtle in healthy vision, become prominent and distracting in VSS.^[22] Photophobia, affecting a majority of patients, denotes an exaggerated sensitivity to light that provokes discomfort or pain in everyday illumination levels, often necessitating sunglasses indoors or avoidance of bright environments. Despite its prevalence, standard ophthalmologic tests reveal no underlying retinal or corneal abnormalities.^[22] Nyctalopia, or impaired night vision, is experienced by about 44% of individuals with VSS and involves difficulty adapting to low-light conditions, such as driving at dusk or navigating dimly lit rooms, even though retinal electrophysiology remains normal. This symptom underscores the cortical rather than peripheral origin of the visual disturbances in the syndrome.^[22]

Secondary visual and non-visual symptoms

Patients with visual snow syndrome (VSS) frequently experience tinnitus, characterized by persistent ringing, buzzing, or humming in the ears, reported in approximately 75% of cases.^[12] This auditory symptom often parallels the intensity and chronicity of the visual snow, suggesting shared underlying sensory processing disruptions.^[9] Perceptual disturbances, such as depersonalization and derealization, are common non-visual symptoms, manifesting as a sense of detachment from oneself or the surrounding environment. Nearly 45% of VSS patients report experiences of depersonalization, contributing to feelings of unreality that can significantly affect daily functioning.^[23] Other secondary symptoms include headaches, often described as chronic or tension-type, sensations of dry eyes leading to discomfort and irritation, and mild cognitive fog, encompassing difficulties with concentration, memory, and mental alertness. Anxiety and depression are also commonly reported, with high rates impacting daily life.^[24]^[17]^[23] These symptoms exhibit variability, often intensifying with fatigue, stress, or poor sleep, yet they typically persist chronically without spontaneous resolution over years.^[13]

Diagnosis

Clinical assessment

The diagnosis of visual snow syndrome (VSS) is based on proposed criteria requiring persistent visual snow—described as dynamic, continuous tiny dots across the entire visual field—for at least three months, plus at least two additional visual symptoms such as palinopsia, enhanced entoptic phenomena (e.g., floaters, blue field entoptic phenomenon), photophobia, or nyctalopia, in the absence of other explainable causes.^[10] The clinical assessment begins with a comprehensive history taking to characterize the patient's symptoms and their evolution. Clinicians elicit details on the onset of visual snow, ensuring the symptom has been present continuously for at least three months. The history also covers potential triggers such as stress, illness, or medication use, the progression of associated visual disturbances like palinopsia or photophobia, and non-visual symptoms including tinnitus or sensory hypersensitivity. The impact on daily functioning, including reading, driving, or work, is evaluated to gauge severity and quality-of-life effects. Validated scales, such as the Visual Snow Handicap Index (VSHI), are administered to quantify symptom intensity and track changes over time.^[25]^[26]^[27] Ophthalmological examination follows to rule out primary ocular pathology. Standard tests include measurement of visual acuity, color vision, pupillary light reflexes, and intraocular pressure, which are expected to be normal in VSS. Funduscopy and slit-lamp biomicroscopy reveal no retinal or anterior segment abnormalities, while automated perimetry demonstrates full visual fields without defects. Ancillary tests like full-field electroretinography (ERG) are performed to exclude retinal dysfunction, yielding normal results that support the cortical origin of symptoms in VSS.^[10] Neurological evaluation is conducted to assess for central nervous system involvement. A full neurological exam checks for focal deficits, such as motor weakness, sensory loss, or coordination issues, which are absent in uncomplicated VSS. Brain magnetic resonance imaging (MRI), often with gadolinium contrast, is routinely obtained to exclude structural lesions like tumors, vascular malformations, or demyelinating plaques that could produce similar visual phenomena; findings are typically normal. If indicated by history, electroencephalography (EEG) may be included to rule out epileptiform activity, though it seldom reveals abnormalities in VSS.^[16]^[28] Patient-reported outcome measures complement the assessment by capturing subjective symptom burden. Questionnaires developed since 2022, including those assessing visual and perceptual disturbances alongside emotional impacts, enable standardized evaluation of severity and functional impairment. These tools facilitate objective monitoring in clinical settings and research, emphasizing the chronic, debilitating nature of VSS without identifiable treatable causes.^[29]

Differential diagnosis

Visual snow syndrome (VSS) is a diagnosis of exclusion, necessitating the ruling out of other neurological, ophthalmological, and psychiatric conditions that may present with similar persistent visual disturbances.^[30] Migraine aura, particularly persistent migraine aura without infarction, is a primary differential consideration due to overlapping symptoms such as photopsia and scotoma. Unlike the constant, pan-field visual snow in VSS, migraine aura is typically episodic and often accompanied by headache, with symptoms lasting minutes to hours that may respond to migraine-specific treatments like triptans or preventive therapies. Distinction relies on clinical history and the absence of a clear migraine pattern in VSS patients, though both may show normal neuroimaging.^[31] Hallucinogen persisting perception disorder (HPPD) mimics VSS through prolonged visual perceptual changes, including trailing or afterimages, but is distinguished by a clear history of hallucinogen use (e.g., LSD or psilocybin) preceding onset, with symptoms that may improve over time in contrast to the chronic persistence in VSS. No specific treatment differentiates them, but the etiological link to substance exposure guides diagnosis.^[4]^[32] Retinal disorders, such as vitreoretinal traction or posterior vitreous detachment, can produce persistent visual phenomena resembling snow or floaters, but these are localized rather than bilateral and dynamic. Ophthalmologic examination, including optical coherence tomography (OCT) and funduscopy, typically reveals structural abnormalities absent in VSS, confirming the need for exclusion via imaging.^[22] Psychiatric conditions, including schizophrenia or delusional disorders, may involve visual hallucinations that superficially overlap with VSS, but these are usually formed (e.g., people or objects) rather than the unformed, static-like noise characteristic of visual snow. Comprehensive psychiatric evaluation, often showing insight preservation in VSS unlike in psychosis, aids differentiation, with no response to antipsychotics expected in VSS.^[28] Recent guidelines emphasize normal neuroimaging (MRI or CT) as crucial to exclude structural lesions or vascular events mimicking persistent aura, reinforcing VSS as a functional rather than organic disorder in the absence of such findings.^[28]

Pathophysiology

Proposed neurological mechanisms

One leading hypothesis for the pathophysiology of visual snow syndrome (VSS) involves cortical hyperexcitability in the visual cortex, where overactive neural activity amplifies intrinsic neural noise, resulting in the perception of persistent static-like disturbances across the visual field.^[33] This mechanism posits that a reduction in inhibitory processes within the visual processing areas leads to heightened responsiveness to even minimal stimuli, manifesting as the core visual snow phenomenon.^[34] Another proposed mechanism is thalamocortical dysrhythmia, characterized by abnormal oscillatory interactions between the thalamus and cerebral cortex, which disrupt normal sensory filtering and generate ongoing perceptual noise in the visual pathway.^[35] In this model, desynchronized rhythms fail to properly gate sensory input, leading to a continuous overflow of irrelevant signals that patients experience as flickering dots and other dynamic visual anomalies.^[36] A related concept involves deficiency in gamma-aminobutyric acid (GABA), the primary inhibitory neurotransmitter in the brain, particularly within visual pathways, where reduced GABAergic transmission diminishes the suppression of excitatory signals and contributes to unchecked neural firing.^[37] This imbalance is thought to underlie the hypersensitivity to visual stimuli observed in VSS, as insufficient inhibition allows for exaggerated processing of background neural activity.^[38] Genetic factors have also been implicated, with rare reports of familial clustering suggesting a possible genetic predisposition to VSS, although no specific causative genes have been identified as of 2025.^[39] These hereditary elements are hypothesized to interact with environmental triggers to alter neural excitability thresholds in susceptible individuals.^[33]

Supporting evidence from studies

Functional neuroimaging studies using fMRI and PET have provided evidence of altered metabolic activity in visual processing regions among individuals with visual snow syndrome (VSS). In a BOLD fMRI study, patients exhibited hyperactivation in the lingual gyrus and middle occipital gyrus (extrastriate cortex) during visual stimulation compared to healthy controls, suggesting enhanced responsiveness in early visual areas.^[40] Complementary PET imaging revealed relative hypermetabolism in the lingual gyrus and cuneus, with peak increases up to 24% (pFWE < 0.05), indicating heightened energy demands in these extrastriate regions that align with the hyperexcitability hypothesis.^[41] These findings from 2020 and 2022 studies, including work by Puledda et al., support persistent cortical overactivity as a core feature of VSS pathophysiology.^[42] Electroencephalography (EEG) and magnetoencephalography (MEG) investigations have demonstrated abnormalities in oscillatory activity, particularly in the gamma band, pointing to cortical instability. A MEG study found significantly increased gamma power (30-80 Hz) over the primary visual cortex in VSS patients during rest and visual tasks, alongside reduced phase-amplitude coupling between alpha and gamma rhythms, which disrupts normal neural synchronization and may contribute to perceptual disturbances.^[36] This elevated gamma activity, observed in a cohort followed longitudinally into 2022, reflects hyperexcitable and disorganized visual processing, consistent with thalamocortical dysrhythmia models. Recent 2025 EEG studies have further shown unstable resting-state microstates in VSS, indicating widespread cortical network instability.^[43] Pharmacological challenges with lamotrigine, an anticonvulsant that inhibits glutamate release, have offered insights into excitotoxic mechanisms. Magnetic resonance spectroscopy (MRS) in VSS patients showed elevated glutamate and glutamine levels in the occipital cortex, indicating potential glutamatergic hyperactivity that could drive symptom persistence.^[40] Lamotrigine administration led to symptom reduction in responsive cases by modulating excessive glutamate signaling, thereby supporting the role of excitotoxicity in VSS and validating targeted interventions against cortical hyperexcitability.^[44] Recent cohort analyses have linked autonomic nervous system activity to sensory processing issues in VSS. In a 2025 study of 26 patients, heart rate variability (HRV) measurements revealed links between parasympathetic activity and increased gamma oscillations, suggesting autonomic influences on visual cortex plasticity and perceptual hypersensitivity.^[45] A 2025 analysis also identified altered functional connectivity strength between cortical areas in VSS, further supporting network-level dysregulation.^[46]

Epidemiology

Prevalence and demographics

Visual snow syndrome (VSS) is estimated to affect approximately 2% of the general population, based on population-based surveys in the UK. In a large online cohort of over 1,000 participants, the prevalence of visual snow symptoms was 3.7%, while full VSS meeting diagnostic criteria was 2.2%. Recent studies as of 2025 indicate variations, with 8.6% prevalence of VSS in US children aged 5-17 and ~1% in an Italian adult cohort.^[47]^[48] The condition is likely underdiagnosed due to limited awareness among clinicians and overlap with other visual disturbances, potentially leading to higher detection rates in specialized neurology or headache clinics, where it may constitute a notable proportion of persistent visual complaint cases. Demographically, VSS typically onsets during late adolescence or early adulthood, with a mean age of onset of 21 years, though approximately 40% of patients report symptoms persisting since early childhood. The average age of diagnosed individuals is around 29 years. Most studies indicate no overall sex predominance, with roughly equal distribution between males and females, although some cohorts show a slight female bias at a ratio of 1.6:1. No strong ethnic or racial predispositions have been consistently reported across studies. Key risk factors include a history of migraine, which overlaps with VSS in 40-50% of cases. Head trauma, especially repetitive mild traumatic brain injury, has been linked to symptom onset in certain patients. Anxiety disorders and chronic stress are also frequently associated, potentially acting as triggers or exacerbators. Global recognition of VSS has increased since the proposal of formal diagnostic criteria in 2014, facilitating more consistent identification worldwide. The Visual Snow Initiative, founded in 2018, supports patient registries and research efforts to enhance epidemiological understanding and awareness.

Disease course and prognosis

Visual snow syndrome (VSS) follows a chronic course, with symptoms typically remaining stable or exhibiting slow progression over many years. A 2022 long-term follow-up study initially involving 78 patients diagnosed in 2011 reassessed 40 after a mean of 7 years, finding persistent symptoms in all without spontaneous resolution. Visual snow was less bothersome overall (most disturbing for 42% vs. 72% initially), with minor improvements in some secondary symptoms like palinopsia (7.5%) and nyctalopia (5%), though entoptic phenomena became more bothersome in 17.5%.^[6] The prognosis for VSS is generally favorable in terms of avoiding degenerative changes, as the disorder does not lead to progressive visual loss or structural damage to the eyes or brain. There is no evidence of spontaneous remission, and the condition is considered lifelong for most individuals, though rare reports suggest mild improvement in symptom intensity with advancing age in isolated cases. VSS typically emerges in young adulthood, influencing a prolonged disease trajectory that spans decades.^[16]^[6] Factors such as stress can significantly influence the disease course by exacerbating symptom severity, leading to temporary flares during periods of psychological or physical strain. Complications from VSS are primarily non-physical, with minimal risk of direct harm to vision or overall health; however, untreated cases carry a high likelihood of secondary anxiety, affecting around 45-50% of patients and potentially compounding the burden of the disorder.^[15]^[49]^[50]

Comorbidities

Associated medical conditions

Visual snow syndrome (VSS) frequently co-occurs with migraine, with comorbidity rates estimated at 50–70% among affected individuals, particularly those experiencing migraine with aura. This association may stem from shared disruptions in thalamocortical pathways, though no direct causal relationship has been established.^[4]^[51] Tinnitus is another common associated condition, reported in approximately 60% of VSS patients, often presenting as bilateral, continuous, and non-pulsatile. The overlap suggests potential central nervous system issues in auditory-visual sensory integration, with bidirectional associations observed in clinical studies.^[4]^[52] VSS also shows links to other sensory processing disorders, such as fibromyalgia (reported in up to 7% of cases) and persistent postural-perceptual dizziness (PPPD), though specific prevalence rates for PPPD are not well-established. These comorbidities highlight broader sensory hypersensitivity but lack confirmed causality, as noted in recent reviews.^[9]

Impact on mental health and quality of life

Individuals with visual snow syndrome (VSS) frequently experience significant psychological distress, including elevated rates of anxiety and depression. Studies indicate that current depression affects approximately 58% of VSS patients, while current anxiety impacts about 50%, often stemming from the chronic and pervasive nature of visual disturbances.^[53] These conditions are closely linked to the ongoing sensory overload and uncertainty caused by symptoms, exacerbating emotional burden.^[50] A 2025 patient-reported outcome study further underscores this, revealing a higher prevalence of anxiety, sadness, and depersonalization/derealization among VSS participants compared to controls.^[29] The syndrome profoundly diminishes quality of life, particularly in performing everyday visual tasks. Activities such as driving and reading become challenging due to the persistent static overlay, which impairs focus and visual processing, leading to frustration and avoidance behaviors.^[54] Social isolation is common, as patients often encounter invalidation of their symptoms by others, including healthcare providers, fostering feelings of alienation and misunderstanding.^[54] This stigma, sometimes manifesting as perceptions of symptoms being "imaginary" or psychosomatic, compounds emotional strain and hinders social engagement.^[55] Coping mechanisms play a vital role in mitigating these effects, with patient-led support groups offering essential peer validation and shared strategies. The Visual Snow Initiative facilitates monthly virtual support sessions, where individuals discuss emotional challenges and build community, reducing isolation through mutual understanding.^[55] Over the long term, VSS leads to increased healthcare utilization, as patients typically consult multiple specialists before diagnosis due to the elusive nature of the condition.^[17] However, adaptive strategies, such as prolonged exposure to visual noise patterns, can temporarily alleviate symptoms and enhance functioning by desensitizing neural pathways, promoting gradual improvement in daily adaptation.^[56]

Treatment and management

Pharmacological interventions

Lamotrigine, an anticonvulsant that modulates glutamate release and reduces neuronal hyperexcitability, is regarded as a first-line pharmacological option for visual snow syndrome (VSS).^[57] Open-label trials and case series from 2014 to 2024 have demonstrated partial remission of visual snow in 50-70% of patients, with response rates varying by study; for instance, one analysis reported efficacy in 61.5% of cases.^[7] Dosing typically begins at 25 mg daily, titrated slowly to 200 mg daily to minimize risks, though higher maintenance doses up to 300 mg have been used in divided administrations.^[58] Common side effects include rash, which can be severe and requires monitoring, particularly during initial titration.^[59] Topiramate and acetazolamide, both carbonic anhydrase inhibitors, have been trialed primarily for associated photophobia and palinopsia in VSS.^[60] Topiramate dosing starts at 25 mg daily and may increase to 200 mg, showing partial improvement in approximately 28.5% of cases across nine studies involving 14 patients, though benefits are often outweighed by side effects like cognitive slowing.^[7] Acetazolamide, administered at doses around 750 mg daily, yields similar variable results for photophobia but lacks robust substantiation for core visual snow symptoms.^[1] These agents are hypothesized to alleviate symptoms via pH modulation in the brain, potentially addressing cortical hyperexcitability linked to VSS pathophysiology.^[57] Antidepressants such as selective serotonin reuptake inhibitors (SSRIs) and anxiolytics like benzodiazepines are not effective for core VSS symptoms but may address comorbid anxiety and improve overall quality of life.^[61] Benzodiazepines provide temporary partial improvement of visual snow symptoms in up to 71.4% of patients, though they do not effectively target core VSS symptoms long-term and risks of dependency and tolerance limit use.^[7] SSRIs are occasionally prescribed for co-occurring mood disorders; however, serotonin reuptake inhibiting antidepressants, including SSRIs, have been identified as a potential trigger for visual snow syndrome in some patients as of November 2025.^[62] Evidence for these interventions remains limited to open-label studies and small case series, with no randomized controlled trials establishing definitive efficacy; a 2025 review confirms no FDA-approved treatments for VSS, and side effects such as rash, cognitive impairment, and dependency are common across agents.^[7] Treatment selection should consider individual hyperexcitability profiles and comorbidities, with close monitoring required.^[53]

Non-pharmacological strategies

Non-pharmacological strategies for managing visual snow syndrome (VSS) focus on symptom alleviation through environmental adjustments, optical aids, and rehabilitative therapies, often providing partial relief for associated visual disturbances such as photophobia and nyctalopia.^[63] Tinted lenses, particularly FL-41 rose-tinted glasses, have shown promise in reducing photophobia, a common comorbidity in VSS. In a retrospective analysis of 25 patients, FL-41 or similar chromatic filters (e.g., BPI-Omega) led to at least a 50% reduction in the frequency and intensity of visual snow for many participants, though effects on core static varied.^[64] Approximately 80-90% of individuals with VSS report symptom improvement, including decreased light sensitivity, when using customized tints that block aggravating wavelengths like blue-green light.^[65] Lifestyle modifications play a key role in symptom management by minimizing triggers and supporting neurological stability. Stress reduction techniques, such as mindfulness-based cognitive therapy, help alleviate exacerbated visual disturbances, with preliminary studies indicating improved coping and reduced perceptual overload.^[66] Avoiding caffeine and alcohol is recommended, as these substances can intensify symptoms by disrupting neurotransmitter balance and sleep; patient reports and surveys consistently identify them as common aggravators.^[50] Dark adaptation training, involving gradual exposure to low-light environments and consistent sleep hygiene, may enhance tolerance to nyctalopia by promoting visual system recovery during rest.^[67] Neuro-optometric therapy offers targeted interventions for entoptic phenomena and visual processing issues in VSS, though evidence remains limited to small-scale studies. This approach includes vision exercises to improve eye movements and fixation stability, combined with tinted lenses, benefiting a majority of patients in case series by reducing dynamic visual noise.^[63] A feasibility study of neuro-optometric rehabilitation therapy (NORT) in VSS patients demonstrated improvements in visual symptoms and quality of life, but larger trials are needed to confirm efficacy.^[68] Supportive care emphasizes a multidisciplinary framework involving neurologists, neuro-ophthalmologists, and psychologists to address the holistic impact of VSS. Patient education on the condition's typically benign and permanent nature fosters acceptance and reduces anxiety, with guidelines recommending discussions on symptom persistence to improve adherence to management plans.^[69] This collaborative model integrates optical and psychological support, enhancing overall functioning without relying on medications.^[70]

History and research

Historical background

Prior to the formal identification of visual snow syndrome (VSS), its core symptom of persistent visual static was frequently misattributed to complications of migraine, such as persistent aura, or to psychiatric conditions including psychosis, leading to delayed recognition as a distinct neurological entity. Advances in neuroimaging, including functional MRI, played a crucial role in differentiating VSS from these conditions by revealing hyperactivity in visual processing networks independent of migraine activity. The earliest systematic clinical report of symptoms resembling VSS appeared in 1995, when Liu et al. described a series of ten migraine patients experiencing persistent positive visual phenomena, characterized as simple, continuous "visual static" or tiny flickering dots across the entire visual field, lasting months to years. During the 2000s, growing discussions in online patient forums and migraine communities further amplified awareness, enabling affected individuals to connect, describe shared experiences, and advocate for medical attention beyond migraine-related explanations.^[60] A pivotal advancement occurred in 2014 with the publication by Schankin et al. in the journal Brain, which formalized VSS as a unique syndrome through a comprehensive study involving patient interviews, surveys, and neuroimaging; this work established core diagnostic criteria, including continuous visual snow accompanied by additional symptoms like photophobia and tinnitus, while excluding it as a mere migraine variant. Key milestones in VSS recognition followed, including the 2018 founding of the Visual Snow Initiative, a nonprofit organization dedicated to advancing research, education, and support for those affected.^[71] In December 2024, the World Health Organization approved inclusion of VSS in the ICD-11 classification under specified disorders of the visual pathways or centers (code 9C4Y), with implementation beginning in 2025, marking its official acknowledgment as a neurological disorder and facilitating improved diagnosis and resource allocation globally.^[20]

Recent developments

In 2024, a comprehensive review supported by the National Institutes of Health (NIH) discussed the use of self-reports and questionnaires for assessing VSS symptom severity in clinical and research settings.^[3] Ongoing clinical trials as of 2025 include NCT06018103, a Phase II randomized controlled trial evaluating mindfulness-based cognitive therapy (MBCT-vision) for VSS over 24 weeks to assess impacts on symptoms and quality of life. Another trial, NCT06961864, explores brain function in VSS using adaptation to visual stimuli and neuroimaging.^[72]^[73] Investigations into retinal structure via optical coherence tomography (OCT) scans are used to exclude other conditions mimicking VSS, supporting differential diagnosis.^[74] These developments underscore a shift toward multimodal approaches in VSS management.^[69]

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Nov 10, 2021 · Visual snow syndrome (VSS) is a clinical disorder characterized by pan-field visual disturbance. It is a diagnosis of exclusion since its pathophysiology ...
[28]
Differential Diagnosis of Visual Phenomena Associated with Migraine
Jan 9, 2023 · In this review we focus on two key visual disorders that are directly or indirectly connected to migraine: visual aura and visual snow syndrome (VSS).
[29]
Visual Snow: Updates on Pathology - PMC - PubMed Central
Mar 2, 2022 · Patients with visual snow syndrome (VSS) report seeing continuous, uncountable, dynamic, tiny dots flickering across their entire visual field.Introduction · Visual Snow Mimics · Potential Mechanisms Of...
[30]
Visual contrast perception in visual snow syndrome reveals ...
May 24, 2022 · Cortical hyperexcitability is a potential pathophysiological ... visual snow syndrome alone and visual snow syndrome with migraine. In ...
[31]
Visual snow: A thalamocortical dysrhythmia of the visual pathway?
... thalamocortical dysrhythmia that results in a disorder of visual processing. ... Visual snow syndrome: What we know so far. 2018, Current Opinion in Neurology.
[32]
Cortical oscillatory dysrhythmias in visual snow syndrome
These results suggest that rhythmical brain activity in the primary visual cortex is both hyperexcitable and disorganized in visual snow syndrome.
[33]
[PDF] Persistent Visual Noise (Visual Snow Syndrome) | Scient Open Access
Oct 4, 2017 · Figure 1(A): Shows the visual noise that seen by the patient of visual snow syndrome ... It is believed that deficiency of (GABA), the most ...
[34]
(PDF) Visual snow syndrome: recent advances in understanding the ...
Visual snow syndrome: recent advances in understanding the pathophysiology and potential treatment approaches ... GABA‐A and NMDA receptors, as well as ...Missing: mechanism | Show results with:mechanism
[35]
Research with VSI | Visual Snow Initiative
Potential genetic factors and comorbid conditions ... Every donation to the Visual Snow Initiative funds critical Visual Snow Syndrome (VSS) research.
[36]
Insular and occipital changes in visual snow syndrome - PubMed
Mar 10, 2020 · Objective: To investigate the pathophysiology of visual snow (VS), through a combined functional neuroimaging and magnetic resonance ...Missing: PET hypermetabolism 2013-2024
[37]
Simultaneous 18F-FDG PET/MR metabolic and structural changes ...
Dec 30, 2022 · Patients with VSS have highly significant structural and metabolic abnormalities in the visual and limbic system.
[38]
Neuroimaging in Visual Snow - A Review of the Literature - Frontiers
The clinical manifestations of visual snow syndrome (VSS) were first described by Liu et al. in 1995, who reported a cohort of ten patients with persistent ...
[39]
[PDF] Visual Snow Syndrome
There have been considerable research efforts into ascertaining the patient history, defining characteristics, categorization, and diagnostic aspects of the.
[40]
New Study: Enhanced Neural Plasticity of the Primary Visual Cortex ...
A study from the Center for Neurocognitive Research (MEG Center) in Moscow provides new insight into the role of neuroplasticity in Visual Snow Syndrome (VSS).
[41]
Visual Snow Syndrome: Can Anxiety Make You See Spots?
Oct 24, 2022 · But it is clear that visual snow syndrome causes distress and greatly affects the quality of life of those with it, which could lead to anxiety ...Anxiety connection · Causes · Symptoms · TreatmentMissing: exacerbates | Show results with:exacerbates
[42]
The Psychiatric Symptomology of Visual Snow Syndrome - PMC
Jul 30, 2021 · VSS patients showed high rates of anxiety and depression, depersonalisation, fatigue, and poor sleep, which significantly impacted quality of life.Missing: dry fog
[43]
Visual Snow Syndrome as a Network Disorder: A Systematic Review
Oct 3, 2021 · The exact prevalence is still unknown, but up to 2.2% of the population could be affected. Presently, there is no established treatment, and the ...
[44]
Two hundred and forty-eight cases of visual snow: A review of ...
Feb 20, 2021 · Of the 449 charts reviewed, 248 patients described seeing visual snow in part or all of their vision. Thirty-eight reported transient visual ...
[45]
Visual Snow Syndrome in Patient with Migraine: Case Report and ...
Feb 28, 2024 · Visual snow syndrome (VSS) is a neurological vision disorder manifested by flickering black or white dots in the visual field. Coloured dots, ...Missing: dry | Show results with:dry
[46]
Treatment effects and comorbid diseases in 58 patients with visual ...
Of the 36 patients who filled in the mood disorder questionnaire, current depression was present in 21 (58.3%) and current anxiety in 18 (50.0%).Missing: mental | Show results with:mental
[47]
Visual snow syndrome: the visual approach - Emianopsia
Mar 5, 2025 · VSS is typically diagnosed by exclusion, following the official diagnostic criteria developed by the Visual Snow Initiative. Neuro ...
[48]
Visual Snow Syndrome Support Group: What to Expect & More
The Visual Snow Initiative (VSI) and the AnCan Foundation have partnered together to create the first video chat support group for individuals affected by ...
[49]
Adapting to Visual Noise Alleviates Visual Snow - PMC - NIH
Dec 20, 2023 · We report the first intervention that can temporarily eliminate the visual snow symptom, allowing many observers to see the world without snow for the first ...Missing: variation lighting
[50]
Insights into pathophysiology and treatment of visual snow syndrome
Visual snow syndrome is a debilitating disorder characterized by tiny flickering dots (like TV static) in the entire visual field and a set of accompanying ...
[51]
Visual Snow: a Potential Cortical Hyperexcitability Syndrome
Visual snow (VS) is a rare disorder manifesting with a persistent visual phenomenon of seeing numerous tiny snow-like dots throughout the visual field.Missing: glutamate excitotoxicity
[52]
Lamotrigine can lead to remission of visual snow symptoms
Oct 8, 2019 · Researchers evaluated pharmacologic treatment options for visual snow and reported the prevalence of comorbid diseases.Missing: glutamate excitotoxicity
[53]
Visual snow: A systematic review and a case series - Sage Journals
Aug 9, 2022 · Visual Snow Syndrome is a recently recognized neurological condition presenting, continuous, tiny dots across the entire visual field.Systematic Review · Clinical Features · Visual Evoked Potentials...
[54]
Medications and Supplements for Visual Snow Syndrome (VSS)
The best data available shows lamotrigine being effective in 8 out of 36 cases (22%). Benzodiazepines. Typically prescribed for anxiety, muscle relaxation, and ...Missing: 2014-2025 | Show results with:2014-2025<|control11|><|separator|>
[55]
Evaluation of treatment response and symptom progression in 400 ...
The study confirms clinical experience that medications are generally ineffective in VSS, with the exception of vitamins and perhaps benzodiazepines.
[56]
Neuro-optometric treatment for visual snow syndrome - NIH
May 30, 2023 · Differential diagnosis of visual phenomena associated with migraine: spotlight on aura and visual snow syndrome. Diagnostics 13, 252 (2023) ...
[57]
Historical, Diagnostic, and Chromatic Treatment in Visual Snow ...
Aug 6, 2025 · 24 In a study of 25 patients, FL-41 or BPI-Omega filtered lenses resulted in at least 50% reduction in frequency and intensity of VS. 25 Lastly, ...
[58]
Chromatic Filters & Tinted Lenses for Visual Snow Syndrome
Studies suggest that chromatic filters and tinted lenses can be highly effective for many individuals with Visual Snow Syndrome (VSS). Approximately 80-90% of ...
[59]
Mindfulness and MBCT-vision (mindfulness-based cognitive therapy ...
This perspective paper examines the application of mindfulness-based cognitive therapy modified for visual symptoms (MBCT-vision) as an intervention for VSS.
[60]
Tips for Managing Visual Snow Syndrome
This guide provides information on various strategies and lifestyle modifications that can help alleviate VSS symptoms.
[61]
The efficacy of neuro-optometric visual rehabilitation therapy in ...
Dec 4, 2022 · This study intends to evaluate the feasibility of Neuro-Optometric Rehabilitation Therapy (NORT) to treat Visual Snow Syndrome (VSS).Missing: evidence | Show results with:evidence
[62]
Visual Snow Syndrome: Therapeutic Implications - PMC - NIH
Aug 27, 2025 · Details. Discussion of the condition with the patient, Educate patients regarding the typically benign nature. Refer to psychology and ...
[63]
Learn About Visual Snow Syndrome
Because of the neurological and visual components involved, VSS is best managed by a multidisciplinary team of specialists. These may include neuro ...
[64]
About VSI's Founder | Visual Snow Initiative
In 2018, Sierra organized the first Visual Snow Conference and founded the Visual Snow Initiative (VSI), a nonprofit dedicated to raising awareness, providing ...
[65]
Visual Snow Syndrome and Visual Snow Now Have ICD-11 Codes
Visual Snow Syndrome (VSS):. ICD Code: 9C4Y (Specified disorders of the visual pathways or centers); Categorical Classification: Specified Disorders of the ...Visual Snow Syndrome and... · ICD-11 Codes for Visual Snow...
[66]
Visual snow syndrome: recent advances in understanding the...
Visual snow syndrome is characterized by a distinctive combination of visual disturbances, including the visual snow phenomenon (manifesting as visual static), ...
[67]
Enhanced Neural Plasticity of the Primary Visual Cortex in ... - bioRxiv
Feb 12, 2025 · Visual Snow Syndrome (VSS) is a neurological disorder characterized ... We also measured heart rate variability (HRV) during rest and ...
[68]
Study Details | NCT06018103 | MBCT-vision VSS RCT - Clinical Trials
The primary outcome is to compare the severity of the visual symptoms on a 0 to 10 scale between the two groups. Detailed Description. Visual Snow Syndrome (VSS) ...
[69]
Investigating Brain Function in People With and Without Visual ...
The goal of this study is to learn more about the brain pathways and activity involved in creating Visual Snow Syndrome (VSS).
[70]
A Novel Computational Framework for Visual Snow Syndrome
Aug 6, 2025 · This article presents two innovative applications using emerging technologies to help people suffering from VSS.
[71]
How do I recognise and manage visual snow syndrome? | Eye
Apr 16, 2024 · Charles Bonnet syndrome (CBS) hallucinations can be characterised as simple flashes, dots of light or palinopsia. This phenomenon occurs in 40– ...