Advancing from Uncertainty to Understanding
Historical Challenges in Diagnosing Visual Snow Syndrome (VSS)
Obtaining an accurate diagnosis for Visual Snow Syndrome (VSS) has historically been a significant challenge. Due to its visual presentation, individuals experiencing symptoms—and many physicians—initially assumed the problem originated in the eyes. However, referrals to optometrists and ophthalmologists often led to normal clinical findings. This is because VSS is not an eye disease; it is a neurological sensory processing condition that affects visual perception and originates in the brain.
Early Clinical Documentation of Visual Snow
The earliest known clinical reference to visual snow appears in the Transactions of the American Ophthalmological Society (1944). Frank D. Carroll reported six patients who developed persistent visual disturbances following digitalis administration, a medication prescribed for cardiac conditions. Symptoms included “snowy vision,” flashing lights, flickering, flowerlike images, green/yellow visual tints, and colored floaters. Comprehensive eye examinations revealed no abnormalities. Carroll theorized that digitalis impacted the central nervous system, specifically the cerebrum, resulting in these visual phenomena.
Misclassification and Marginalization of VSS
Despite these early observations, Visual Snow Syndrome remained unrecognized for decades. Medical education did not address the condition, and most physicians were unaware of its existence. Among those familiar, VSS was often misclassified as a variant of migraine or mistakenly attributed to psychological factors.
A landmark 1995 study, “Persistent Positive Visual Phenomena in Migraine“ (Liu et al., Neurology), described patients experiencing persistent visual static across the visual field, lasting months to years, despite normal neurological and ophthalmological findings. Although initially considered a migraine-related phenomenon, the continuous, broader symptom profile aligned more closely with what is now formally identified as Visual Snow Syndrome. This study helped pave the way for distinguishing VSS from migraine aura.
While VSS may coexist with migraine in some cases, many individuals develop VSS independently. Unlike migraine aura, which typically resolves, VSS symptoms are continuous and persist 24/7, regardless of headache presence.
From Skepticism to Scientific Validation
For many years, VSS was misinterpreted, dismissed, or incorrectly associated with psychiatric conditions—an outdated and scientifically refuted view. This widespread misunderstanding delayed diagnosis, contributed to stigma, and negatively impacted the mental health of those affected.
However, some physicians recognized VSS as a distinct neurological condition. Yet, due to the absence of targeted research, diagnostic criteria, and treatment protocols, clinical management options were limited.
Formal Recognition and Advancements in Research
Today, Visual Snow Syndrome is formally recognized as a distinct neurological disorder involving both visual and non-visual sensory processing. Visual Snow Syndrome (the disorder) and Visual Snow (the symptom) each have formal diagnostic codes within the International Classification of Diseases, 11th Revision (ICD-11), established by the World Health Organization (WHO). This major milestone was achieved following advocacy efforts and expert testimony from Visual Snow Initiative (VSI) Founder Sierra Domb, along with renowned researchers Dr. Peter Goadsby and Dr. Owen White.
The development of formal diagnostic criteria and advances in neuroimaging and clinical research have improved diagnostic accuracy and reduced rates of misclassification. Collaborative efforts between VSI and leading medical researchers have clarified the differences between VSS and migraine, enhancing clinician education and improving patient outcomes.
Global Research Initiatives and Expanded Resources
Global research efforts funded by the Visual Snow Initiative (VSI) have taken place across multiple countries, driving forward understanding of the biological mechanisms, pathophysiology, and potential treatments for VSS. These international collaborations have been instrumental in validating VSS as a legitimate neurological condition and informing new therapeutic strategies.
Resources that were once unavailable are now accessible to the VSS community, including diagnostic guidelines, a global directory of physicians familiar with VSS, and noninvasive treatment options based on emerging scientific findings.
Since VSI’s founding in 2018, global awareness, education, and research regarding VSS have expanded dramatically, leading to a quadrupling of recognition across clinical and public domains.
Moving Forward: Continued Progress in Awareness and Research
Continued efforts in clinical education, scientific research, and public awareness are essential to advancing diagnosis, improving patient care, identifying targeted therapies, and deepening understanding of this complex neurological condition. As research expands and understanding grows, so too does the potential to enhance outcomes and quality of life for individuals living with Visual Snow Syndrome.
Below are additional details about Visual Snow Syndrome (VSS), its history, and recent advancements in understanding, recognition, and management.
The Progress:
Key Developments for Visual Snow Syndrome (VSS)
Visual Snow Syndrome (VSS): Overview
- Visual Snow Syndrome (VSS) is a neurological disorder that impacts visual perception, sensory processing, auditory function, and cognitive abilities; it does not result from structural abnormalities of the eyes.
- Symptoms of Visual Snow Syndrome (VSS) are estimated to affect 2-3% of the global population.
- The first documented cases of visual snow/static vision were published in 1944 by Frank D. Carroll.
- Individuals of all ages and backgrounds around the world are affected by VSS on a daily basis.
- VSS is a complex network brain disorder caused by disruptions in interconnected neural pathways, including those responsible for vision, rather than a dysfunction in a single brain region.
- VSS involves both hyperactive regions, such as the visual cortex, and downregulated areas like the anterior cingulate cortex, resulting in a range of symptoms that can vary between individuals.
- VSS is linked to abnormal neurotransmission of serotonin and glutamate, as well as increased metabolic activity in the brain, particularly in regions responsible for visual perception and processing.
- Individuals with VSS experience abnormal processing of visual and other sensory information.
- Visual Snow Syndrome is named after its hallmark symptom, visual snow, which is experienced by all individuals with the condition.
- Visual snow is characterized by the constant perception of static, flashing lights, and blinking dots, occurring 24/7, whether the eyes are open or closed.
- Experiencing visual snow is often compared to trying to see through a snowstorm or a shaken snow globe, which is how the condition earned its name.
- However, VSS involves more than just visual snow, as many individuals also experience a range of both visual and non-visual symptoms.
- VSS symptoms can develop either from birth or at any point later in life.
- VSI has heard from individuals affected by Visual Snow Syndrome (VSS) in over 93 countries.
Challenges in Diagnosing Visual Snow Syndrome (VSS)
- Optometric and ophthalmologic (eye) tests often yield "normal" results, as VSS is not related to the structural integrity of the eyes but is instead a neurological condition originating in the brain.
- Many VSS symptoms overlap with those of other medical conditions, often leading to confusion, misdiagnosis, delayed diagnosis, and mistreatment.
- VSS is often mistaken for migraine aura or Hallucinogen Persisting Perception Disorder (HPPD), both of which are distinct conditions with different underlying causes.
- Individuals with VSS were often dismissed or not believed, leading to stigma and a profound negative impact on their mental health and overall well-being.
- It is not uncommon to experience temporary visual snow or static, particularly under certain lighting conditions or after rubbing your eyes. However, the persistent presence of these visual disturbances, both with eyes open and closed, is a hallmark symptom unique to VSS.
- Before scientific research shed light on the condition, some believed VSS was a "supernatural" ability due to the unusual and persistent nature of the visual disturbances.
- Uncertain about the cause of their symptoms, some VSS patients feared they were going blind or that their vision was deteriorating. However, research now confirms that VSS does not lead to permanent blindness, nor is it a degenerative condition.
- The exact cause of VSS remains unknown. However, patients have reported potential triggers for the onset of VSS, including certain medications, extreme stress, traumatic brain injuries, migraines, infectious diseases, surgeries, and other factors.
Advancements and Milestones in Visual Snow Syndrome (VSS)
- VSS is now clinically recognized and scientifically accepted as a distinct, legitimate neurological disorder, characterized by both visual and non-visual symptoms that affect vision, hearing, sensory processing, and cognition.
- Following advocacy efforts by VSI, both Visual Snow Syndrome (the condition) and Visual Snow (the symptom) have received ICD-11 recognition from the World Health Organization.
- Since VSI began its work in 2018, VSS research has quadrupled.
- The rate of misdiagnosis for VSS has significantly decreased compared to previous years
- New discoveries regarding the pathophysiology, biological basis, underlying network mechanisms, and potential treatments for VSS have been made.
- Recent studies have identified potential biomarkers for VSS, with advanced imaging techniques like 7-Tesla MRI and PET scans providing valuable insights into the disruptions of interconnected neural pathways associated with the condition.
- More doctors around the world are now aware of and educated about VSS than ever before, with many expressing a specific interest in helping individuals affected by the condition.
- VSS has been acknowledged by leading medical and scientific institutions and publications, including the World Health Organization (WHO), Mayo Clinic, Cleveland Clinic, National Institutes of Health (NIH), National Institute for Health and Care Research (NIHR), NHS, Healthline, PubMed, Frontiers, Brain Communications, Annals of Neurology, Neurology (American Academy of Neurology), Journal of Neuro-Ophthalmology, and more.
- Through VSI, global VSS experts have collaborated to study and develop solutions for VSS, advancing research and treatment options for those affected.
- There are now resources, educational content, and diagnostic tools available to assist individuals with VSS and their physicians in understanding and managing the condition.
- Viable, non-invasive treatment options for VSS are now available, with more potential treatments becoming possible if research continues to advance.
- There is more clinical and public interest in VSS than ever before, with increased global awareness, multimedia content, educational tools, resources, and studies being generated to better understand and address the condition.
Support VSS Research Today
Every donation to the Visual Snow Initiative funds critical Visual Snow Syndrome (VSS) research. Your tax-deductible contribution drives global research efforts and creates a meaningful impact on the lives of those affected by VSS.
