Sierra Domb Q&A – Part 2 – Visual Snow Syndrome: Causes and Triggers

Sierra Domb Q&A - Part 2

Visual Snow Syndrome:
Causes and Triggers

by Sierra Domb, Founder & CEO, Visual Snow Initiative


Hello, and thank you so much to everyone who participated in my Q&A! I really appreciate you sharing your thoughtful inquiries and personal stories with me. The Visual Snow Initiative (VSI) team and I are grateful for your continued support for our cause, kind words, and Visual Snow Syndrome (VSS) activism.

Due to the high volume of questions submitted, I combined some that were similar so more people can have their questions answered. I wanted to try my best to help as many people with their inquiries as possible. 

Additionally, my Q&A will be divided into several articles, with relevant questions grouped together for clarity. 

If your question is not directly answered in my Q&A articles, I kindly encourage you to check out the following links, as these pages already likely answer your question and may be helpful. 

Thank you in advance for understanding!

Helpful Resources for Inquiries Regarding VSS, VSI, and more:

Some of the answers to questions that were submitted can be found on our FAQ page, which provides answers to some of the most common questions regarding VSS and VSI, as well as helpful resources and links with further information. 

On our VSS Misconceptions page, we also provide additional education and dispel some of the most common misconceptions regarding the condition. 

For questions inquiring if there are any treatments currently available or tips to help manage VSS, please feel free to visit the Managing VSS page on the VSI website. 

  • VSS/VSI Research pages:
  1. News & Research/Latest Updates
  2. List of Current Research Being Funded
  3. Details of Currently-Funded VSI Studies

VSI has funded several research studies, some of which are upcoming and others that are currently active, exploring biomarkers, the pathophysiology, and potential treatment options (both noninvasive and pharmacological). Further information about VSS will be revealed, giving way to increased knowledge and more potential treatment options for the condition. For study details, the latest updates, and a list of the current types of research we are funding, please access the links above.

For those struggling to find a physician with knowledge of VSS in their area, please access our Physicians Directory where you can search for a doctor or specialist by location.

For those looking for a list of providers with expertise in NORT, this information is available on our Managing VSS > NORT page.


Q: What causes have been found to induce Visual Snow Syndrome in people who get the condition out of nowhere?

Among the people in 93 countries who have reported experiencing the sudden onset of Visual Snow Syndrome (VSS) to the Visual Snow Initiative (VSI), they have attributed the onset of their VSS to a wide variety of causes. Based on VSS patients reports, we make ongoing efforts to further understand the condition and identify common trends amongst the VSS patient population, analyzing if there is a common factor that is linked to onset. According to global VSS researchers, based on their studies and reports from patients or study participants, no singular across-the-board cause for the onset of VSS has yet been identified.

They are investigating a definitive commonality that can be linked to the onset of the condition. For the VSI team, the most common reasons attributed to the onset of VSS that people have shared include medications (especially those related to neurotransmitters, such as SSRIs and benzodiazepines), episodes of anxiety, depression, or panic attacks, migraine episodes, infectious diseases (such as COVID-19), surgeries, concussions/TBIs, and pregnancy. VSS researchers have recently reported that the most common times of sudden onset are adolescent teenage years and young adulthood. A previous study also suggested that VSS is most reported in young adults with an average age of 29. 

Visual snow/static vision (the symptom, not the syndrome) was first documented by Frank D. Carroll in 1944 as a side effect of digitalis, a medication for heart ailments (Transactions of the American Ophthalmological Society). Recent research has revealed valuable information about the origins of the condition, VSS. The origin of VSS has been linked to hyperactivity in the visual cortex (lingual gyrus) of the brain, abnormalities in the visual processing centers of the brain, and alterations in the neural signals between the eyes and brain. The brains of those with VSS have increased metabolic activity, especially in areas involved in visual perception and processing

Research has also demonstrated cortical hyper-reactivity in visual brain areas, indicating a network disorder rather than a focal pathology. Imaging studies (7-Tesla MRI and FDG-PET/MRI) have also shown microstructural and functional connectivity differences in cortical and thalamic regions. Possible biomarkers of VSS have been discovered: abnormalities in glutamatergic and serotoninergic neurotransmission. As research continues to grow, so will our understanding about the origins of VSS.

Q: When were the first cases of visual snow/static vision documented?

Visual snow/static was first reported in the Transactions of the American Ophthalmological Society in 1944. Frank D. Carroll published descriptions of 6 patients experiencing visual disturbances induced by digitalis, a medication for heart ailments. These included “snowy vision, flashing and flickering lights, flowerlike figures, green and yellow vision, and colored floaters”. All 6 patients underwent ophthalmic (eye) examinations, and findings were negative. Carroll surmised that digitalis impaired the central nervous system, stimulating the cerebrum to cause visual hallucinations and colored vision.


Carroll FD. Visual Symptoms Caused by Digitalis. Trans Am Ophthalmol Soc. 1944;42:243-9. PMID: 16693349; PMCID: PMC1315130.

Shi L, Sun LD, Odel JG. Colored floaters as a manifestation of digoxin toxicity. Am J Ophthalmol Case Rep. 2018 Mar 2;10:233-235. doi: 10.1016/j.ajoc.2018.02.024. PMID: 29780940; PMCID: PMC5956671.

Q: Does stress make Visual Snow Syndrome (VSS) worse?

Stressful events, either physical or mental, absolutely affect the intensity of Visual Snow Syndrome. Stress, in general, can initiate flare-ups and worsen symptoms associated with a variety of medical conditions; the same is true for VSS. This is also the case for anything that initiates a serious inflammatory response. However, due to its neurological origin, VSS is related to the human body’s overall nervous system. The nervous system of those with VSS is typically more sensitive, making them susceptible to sensory stimuli and other stimulants like caffeine and certain medications. Anything that impacts the overall nervous system and induces neurotransmitter alterations within the brain, such as physical or mental stress, can affect VSS. These can include medications (especially those related to neurotransmitters, such as SSRIs and benzodiazepines), episodes of anxiety, depression, or panic attacks, migraine episodes, infectious diseases (such as COVID-19), surgeries, concussions/TBIs, and pregnancy — many of which are also common factors people VSS have attributed to the sudden onset of their condition. However, everyone’s case of VSS is different based on their specific symptoms, personal triggers, and medical history; therefore, everyone may not have the same experience. The above rationale is likely why therapeutic interventions and lifestyle changes that calm the autonomic nervous system have been reported to have positive effects for many VSS patients, reducing or stabilizing symptoms. Further exploration into this area is still necessary.

Q: Does Visual Snow Syndrome get worse during menstruation or pregnancy?

Many women and teenage girls with Visual Snow Syndrome (VSS) report their symptoms worsen during menstruation and/or post-ovulation, during the luteal phase leading up to menstruation. The primary observation has been that visual snow/static can become more intense, but many other visual and non-visual symptoms can as well. Premenstrual Syndrome (PMS) and Premenstrual Dysphoric Disorder (PMDD) can exacerbate VSS. Some patients also report the onset of VSS occurred for them during pregnancy while other women who already had VSS shared that it worsened their preexisting symptoms. However, this is not the case for everyone with VSS, some of whom observed no difference in their symptoms during pregnancy. In all these cases, it was reported that symptoms returned to baseline once PMS, PMDD, pregnancy, and the associated hormonal fluctuations subsided.

PMS, PMDD, and pregnancy can also aggravate various medical conditions due to hormonal fluctuations and changes in the body’s physiology. However, a critical and unique consideration for neurological disorders, such as VSS, is that PMS, PMDD, and pregnancy can exacerbate changes in neurotransmitter activity/imbalances, especially during the menstrual cycle. 

In terms of hormones, they have widespread effects on the brain, including neurotransmitter regulation, neuronal function, and neuroplasticity. Changes in hormone levels can influence the symptoms of neurological disorders that are sensitive to hormonal fluctuations. PMS and PMDD are also associated with alterations in neurotransmitter activity, particularly serotonin. Serotonin plays a key role in mood regulation, and disruptions in serotonin levels during PMS or PMDD can exacerbate non-visual symptoms of VSS such as depression, anxiety, and derealization. Nausea and dizziness, common symptoms of VSS, PMS, PMDD, and pregnancy, may also get worse. Additionally, some women experience heightened sensitivity to pain during PMS or PMDD, which can worsen VSS symptoms like migraines, headaches, sensory disturbances/“brain zaps”, and paresthesia. Moreover, PMS and PMDD are associated with increased inflammation in the body and insomnia, a common symptom of VSS. Lastly, PMS and PMDD can increase stress levels. The correlation between stress levels and the worsening of VSS has been thoroughly documented.

Q 1: Are depersonalization/derealization, insomnia, and visual distortions common?

Q 2: Has anyone else shared that their symptoms are worse when waking up or going to sleep?

Many people report that their VSS is worse upon waking in the morning or before sleeping at night. (Hours may vary depending on if you are on a night owl or early bird schedule, of course.) In addition to static, people with VSS can experience phosphenes, tinnitus, and other visual disturbances when trying to sleep – all of which can be disorienting and frustrating. Insomnia, depersonalization/derealization, and visual distortions are all common symptoms of VSS. For a full list of visual and non-visual symptoms, please see our VSS Diagnostic Criteria page. We share tips that can help manage this on our Managing VSS > Tips for Managing Visual Snow Syndrome page. 

Q: When did you get visual snow? Was there anything specific that triggered it?

I got up in the morning to go to school, and my vision just seemed off. But I couldn’t quite put my finger on why. I had temporarily “seen stars”, or phosphenes, and “floaters” before when I was dehydrated, a common occurrence in the Florida heat, as well as when my blood sugar was low. I made sure I was hydrated with an electrolyte drink and food to boost my blood sugar before leaving for campus. While driving, the phosphenes and floaters were not as noticeable as when I had first woken up. I was able to reach my destination without issues.

After getting to university, I felt relatively fine and attended my first class as usual. While looking at the classroom whiteboard, I noticed I was seeing small dots. They were more prominent on bare, white surfaces. After my first class, I left campus to get lunch. Driving back to campus, it was then that my vision went black behind the wheel. It was one of the scariest, most traumatizing moments of my life. Familiar with the area and my vehicle, instinctively, I was able to pull over and stop the car. I proceeded to panic, still unable to see. Moments later, my vision returned. When it did, my vision was nowhere near the same as it was before. This incident marks the pivotal point at which I began seeing permanent visual snow/static in my field of vision (with my eyes open and closed). Shortly thereafter, I developed additional symptoms that I had never experienced before, including photophobia, palinopsia, tinnitus, migraines, depersonalization, and more – all the symptoms of Visual Snow Syndrome (VSS); this debilitated me, significantly and negatively impacting my quality of life.

This event also sparked the beginning of my battle with Post-Traumatic Stress Disorder (PTSD). It is a memory that I tried to repress but have ultimately confronted over the years. For a long time, I was scared to drive again or talk about what happened. It reminded me of my vision going black and getting VSS, making me feel like I was there, reliving the trauma each time. However illogical, PTSD even fueled the fear that something scary and devastating like that may happen again. I worked hard to overcome this throughout the years. Being able to share it publicly in my TEDx Talk was a triumphant moment. There was a time when speaking about what happened would have completely derailed my thoughts and speech, sending me into a spiral of panic and confusion. Nothing could be edited out. Yet, I held it together on stage in front of everyone; I went from being paralyzed by the topic to speaking about it and informing others about VSS, a serious issue. Today, I am no longer afraid to talk about what happened and drive comfortably again.

Upon reflection, I tried to determine if I could attribute the onset of my VSS to a specific incident that triggered it. At that time in my life, the only present external trigger was stress associated with challenging life events, which virtually everyone experiences at some point. I am also no stranger to medical problems, as I was born with Autoimmune Dysregulation (AD) and Erythromelalgia (ER). But I learned how to adapt over the years, and they were not flaring-up or significantly impacting my quality of life at that time; I felt relatively “normal” during this period. I experienced AD and ER since I was young, and the symptom profile was always the same for me, becoming very predictable over the years. It is possible they may be tied to my VSS (no current research indicates that), but AD and ER had never caused me any visual symptoms. I never experienced any VSS-like visual symptoms prior to this time (other than temporarily “seeing stars” due to dehydration or hypoglycemia and floaters, which are relatively common and present in people without VSS.) 

It seems that in my case, the onset of my VSS developed spontaneously over the course of a day. It began as barely noticeable in the morning, to the point where I could still function normally despite visual disturbances and anticipated they were temporary. Then, later in the afternoon as I was driving, the onset of VSS in its classic form ensued. It was from that point on that the condition became full-blown, debilitating me and causing me to see static/visual snow 24/7 (with my eyes open and closed). After that incident, I also noticed even more symptoms were developing, including photophobia, palinopsia, tinnitus, migraines, derealization, and more. This was a pivotal point in my VSS journey, what I consider the beginning of it all. 

Q: How were you diagnosed and what was it like? / Which doctor diagnosed you with VSS?

After I experienced the onset of Visual Snow Syndrome (VSS) in 2015, I saw numerous doctors, including optometrists, ophthalmologists, neurologists, and neuro-ophthalmologists. Nobody could figure out what was wrong, let alone offer me a correct diagnosis. They ordered X-Rays, CT scans, MRIs, PET scans, bloodwork, and more. Since I told doctors I was seeing static across my visual field, along with many of the other visual symptoms that accompany VSS, they also conducted seemingly endless Clockwork Orange-like eye exams. All my results came back “normal”. I had also shared that the static was present even with my eyes closed, which finally signaled to one ophthalmologist that a neurological issue may be affecting my vision, related to brain-eye processing. They sent me to a neuro-ophthalmologist, who too suspected the issue was brain-eye related. However, they did not know what condition I had, nor did they understand what was happening to me or why. They braced me that although they did not fully understand it, that my symptoms may be the precursor to blindness. Moreover, my visual and non-visual symptoms were associated with several life-altering neurodegenerative conditions, which might even cause me to die without warning.

It was a very agonizing and intense time. 18 months had gone by, and I still had no answers. I had to leave school and could no longer work or drive. I went online, searching for answers. I saw that others around the world were going through a similar medical odyssey. Everyone seemed frustrated with the healthcare system, depressed, and confused about how to cope. They were desperate for resources and answers about what was causing their symptoms. Having just had my own horrible medical experience and living with fear and uncertainty, I understood what led them to feel hopelessness. I ultimately could not accept these injustices in the medical system and that I may go blind or die without knowing what was truly going on. I became curious about academic and clinical research, if there was any evidence of patients reporting my same symptoms. I began specifically looking for articles related to the symptoms, “snowy vision” and “static in eyes”, which led to an article by Dr. Peter Goadsby detailing Visual Snow Syndrome (VSS). 

It was then that I learned what condition I had this entire time. I immediately reached out to Dr. Goadsby, who diagnosed me with VSS. He is part of what inspired me to host the first Visual Snow Conference at UCSF, start the Visual Snow Initiative, and initiate collaborations between global VSS researchers. We ultimately formed a Global Research Team for VSS. Because getting a diagnosis for VSS patients like me was so difficult, together, we established the first Diagnostic Criteria for VSS. Anywhere in the world, you can show this to your doctor to confirm or refute a diagnosis. This page also contains visual examples of each symptom, so it is easier to explain to your doctor. It is important to inform your primary care physician, but you may want to consider speaking with a specialist such as a neuro-ophthalmologist or neurologist, with expertise in the brain. Ophthalmologists, optometrists, and neuro-optometrists are also involved in VSS. (For more information regarding what to do if you are newly-diagnosed with VSS, please access our VSS Patient Guide. If our proposal for VSS to get an ICD code is approved by the WHO, then getting a VSS diagnosis can become easier for patients and standardized globally.

The following excerpt may also be helpful:

Overview of Visual Snow Syndrome

From the Learn About Visual Snow Syndrome page (Visual Snow Initiative website):

Historically, it has been challenging for people with VSS to receive an accurate diagnosis.

VSS is diagnosed based on a patient’s symptoms and a thorough clinical evaluation, including a comprehensive medical history and a comprehensive eye exam to rule out eye-related conditions. (Optometric and ophthalmological examinations typically yield “normal” results.) In some cases, an MRI or EEG may be ordered to rule out other neurological conditions.

Neuro-ophthalmologists and neurologists are best equipped to address VSS, including some ophthalmologists, optometrists, neuro-optometrists, and vision therapists who are trained in the management/treatment of VSS symptoms. 

The types of physicians involved in VSS include:

  • Neuro-ophthalmologist: Doctor with expertise in both neurology and ophthalmology, addressing visual issues linked to the nervous system
  • Neurologist: Doctor specializing in the diagnosis and treatment of brain, spinal cord, and nervous system disorders
  • Ophthalmologist: Doctor specializing in eye care, diagnosing and treating various eye conditions, and performing surgeries
  • Neuro-optometrist: Vision care professional trained in neurology and optometry, focusing on vision problems related to neurological conditions
  • Optometrist: Vision care professional specializing in visual exams, corrective lenses, and managing common eye conditions

If you suspect you may have VSS, you can refer your doctor to our Diagnostic Criteria.

It can sometimes be difficult to find medical professionals who understand or specialize in VSS. VSI also has a list of physicians from around the world with knowledge of VSS that can help with diagnosis and treatment options. For more information, please see our Physicians & Specialists Directory.

Q 1: Do you have any personal theories regarding the causes of VSS?

Q 2: Can VSS be hereditary: what do you think?

In addition to a possible genetic predisposition, which needs to be explored further, personally, at this time, I believe that the sudden onset of VSS is initiated by physiological changes that impact how the brain and overall nervous system function. Key components include the brain’s occipital lobe (visual cortex, lingual gyrus), neurotransmitter alterations/function, and sympathetic nerve activity. I suspect these physiological changes can be caused by both internal or external factors that involuntarily induce physical or mental stress on the body, such as medical conditions/diseases, medications, traumatic brain injuries (TBIs), surgery, or anxiety/panic attacks. People have attributed the onset of their VSS to a wide variety of causes, with researchers currently unable to identify a common factor for everyone. However, while they may seem unrelated on the surface, the most common causes (such as those mentioned above) can all involuntarily induce physical or mental stress on the body that is capable of affecting the brain and overall nervous system. I suspect that these factors induce physiological changes that can “rewire” the brain, causing it to behave abnormally and ultimately initiating VSS. The brain, as the central control system of the body, plays a crucial role in regulating numerous bodily functions, spanning from visual processing to complex cognitive processes. This would explain why there is such a wide variety of reasons people have gotten VSS, as well as both visual and non-visual symptoms of the condition.

I also believe there is likely a genetic component to the condition, as the VSI team has heard from several pairs of monozygotic twins with the condition, a potential hallmark of a genetic factor. Moreover, this would explain why some people are born with VSS while others experience the sudden onset of the condition. It is possible a VSS gene may be active since birth in some individuals, while for others, the gene becomes active later in life, likely triggered by physiological changes and an episode of physical or mental stress. This would explain why many researchers have found that the most common time of onset is during adolescent teenage years and young adulthood, stressful periods on the body related to hormonal and chemical changes. Additionally, as life progresses, stressful triggers, health risks, and exposure to potential harm tend to increase. It would also explain why VSS can suddenly emerge after surgeries, medication intake, periods of illness or extreme stress, and other episodes of physical or mental bodily stress. Symptoms of many medical conditions with hereditary components can also manifest later on life, not always since birth.

The VSI team is highly interested in exploring all aspects of VSS, including pathophysiology, causes, hereditary factors, various types of treatments, and more. Advancing our understanding of VSS through studies is imperative. I’m curious and excited to see what researchers find in the coming years.

More Answers to Questions

In addition to my other Q&A articles and all the resources I shared within this article, on the Visual Snow Initiative YouTube channel, specifically the VSS News Video Series and The Cure of Understanding Video Series, our team of experts provide answers to a wide range of additional questions related to Visual Snow Syndrome and the Visual Snow Initiative. For any further inquiries, please visit our Contact page: Contact the VSI Team.

Thank you again to everyone who submitted their questions and participated in my Q&A!

-Sierra Domb