Everything You Wanted to Know About Visual Snow
“I first became aware of seeing visual snow around 10-11 years of age (I’m now 47, and it’s never gone away). As far as I know, I’ve always seen visual snow (although for decades, I didn’t know that it had an actual name). In fact, when I say that I became aware of it at the age of 10-11, what I mean is that I learned then that other people don’t see it. Previously, I had thought that everybody experienced this.
The snow appears superimposed over the whole extent of my visual field, and it does look very much like the noise that you see on a TV screen between channels. It is most noticeable over solid surfaces than over textured ones, and I can’t say that its presence bothers me. I usually don’t even notice it unless I’m paying attention to it, and I can go for days or weeks at a time without thinking about it.”
Visual Snow Patient, Susana Martinez-Conde, PhD
Professor of Ophthalmology, Neurology, and Physiology & Pharmacology
Director, Laboratory of Integrative Neuroscience State University of New York (SUNY)
Visual snow is a condition that is considered to be relatively rare, but obtaining exact statistics is not easy because many patients don’t realize they have it or don’t realize that it is not normal. Over the years patients have faced many challenges. It was not regarded as a “real” condition by many doctors. Visual snow patients were often treated similar to those with chronic pain and conditions like fibromyalgia. Many times they were told that it was “all in their head” or the result of past or present illicit drug use.
Times are changing though as patients are calling more attention to their VS and researchers are paying attention. The American Academy of Neurology is taking steps to formally recognize it as a condition or syndrome and put it on the map.
- 1 Everything You Wanted to Know About Visual Snow
- 2 What is Visual Snow?
- 3 Types of Visual Snow
- 4 Causes of Visual Snow
- 5 Other Accompanying Symptoms
- 6 Getting a Diagnosis
- 7 Common Linked Conditions
- 8 Effects of Visual Snow
- 9 Treatments for Visual Snow
- 10 How to Help Someone Suffering from Visual Snow
- 11 If you have Visual Snow
- 12 What’s Ahead for Patients?
- 13 Visual Snow 2019 Update
What is Visual Snow?
Visual snow (VS) is a condition characterized by a disruption in a person’s visual field, usually tiny white and black dots that resemble a television screen with poor reception. Other symptoms that may present visually include photophobia, prolonged afterimages, color swirls, trailing, bright flashes, poor night vision, and floaters. Sometimes the dots are colored and change color very rapidly. While it is not associated with a visual aura that can accompany migraine, many patients who have VS also have migraines. Many people who have a history of drug use, primarily hallucinogenic, have the condition.
The clinical term for visual snow is aeropsia but it may also be referred to as “visual static” or “positive persistent visual disturbance.” It tends to be somewhat unique to each patient although most of the symptoms are widely similar. However, each patient describes their condition with some minute differences that seem to make it unique to them. The visual disturbance can be either persistent, meaning it is always present, or transitory, meaning it is somewhat intermittent. It can also cover the entire visual field or only part.
The condition is often visible in all light conditions, although it is more noticeable under certain light and against backgrounds that are darker. Dim lighting can exacerbate it as can darkness. Some patients report it being particularly bothersome when they are trying to read.
Visual snow is medically determined to be a unique syndrome and is believed to be quite rare. However, doctors disagree about its frequency but do believe that many instances go unreported. This can be due to the patient being unaware that what they are experiencing is abnormal or simply because it doesn’t bother them all that much.
Types of Visual Snow
There are two main types of visual snow: pulse type and broadband. Each refers to how the visual field is disrupted; what the patient sees.
Pulse Type – In this type of visual snow there are dots are uniform in size and are scattered across the visual field. It is described as being similar to drops of water on a car’s windshield during light rain. The dots may be lighter or darker than the dominant or overall color of the scene the patient is viewing. They may also seem to swirl or flicker.
Broadband – In this type of visual snow, there is a fuzzy or snowy appearance over the visual field like a television that gets
poor reception or is turned to an out of service channel. The fuzz or noise may be darker or lighter than the overall color of the scene but it does somewhat obscure the vision. The dots can vary in size.
There are several subtypes or additional visual symptoms of VS. They are consistently found in about a third of patients who have the condition.
- Nyctalopia (impaired night vision)
- Palinopsia (after images, trailing)
- Photophobia (sensitivity to light)
- Entoptic phenomena (self light of the eye, spontaneous photopsia, blue field entoptic phenomenon, floaters)
Headache and migraine are commonly associated with visual snow, particularly when it is beginning or when it worsens. In one study, 59% of the subjects who had the condition also had migraines.
Causes of Visual Snow
Doctors do not know what causes visual snow, but many believe that thalamocortical dysrhythmia is a significant contributor. Thalamocortical dysrhythmia is a disruption of neural activity between the thalamus (a centrally located relay station deep within the brain) and other areas of the brain’s cortex, or outer surface layer. There are also some medical conditions of which VS can be a symptom. The most common include migraine or persistent migraine aura (PMA), hallucinogen persisting perception disorder (HPPD), and optic neuritis (or inflammation of the optic nerve) as a symptom of multiple sclerosis (MS). Excessive use of a computer or smartphone has been linked to the condition as well. Some research also suggests that visual snow is hereditary.
There are a number of health issues, both physical and mental, that seem to be comorbidities of VS. There is some speculation among researchers that there is a link, whether the visual snow led to some of them or it is a symptom of the condition. Some of the most common comorbid conditions with (which does not mean there is a causal link) visual snow include:
- Sleep deprivation (insomnia, fatigue)
- Lyme disease
- Autoimmune disease
Post hallucinogen perceptual disorder (PHPD), also known as “flashbacks” stemming from drug use (hallucinogenic drugs like lysergic acid diethylamide – LSD) has long been thought to be the primary, if not the only, cause of visual snow. While the condition can occur in connection with drug use, sometimes long after the patient has stopped using drugs, researchers are finding that it can occur when the patient has never used any drugs.
Other Accompanying Symptoms
Migraine, with or without aura, is one of the most common symptoms accompanying visual snow. Migraine without aura seems to more often accompany the condition than migraine with aura. There are other symptoms that patients report that seem to be symptoms directly related to VS. Not all patients experience the same symptoms and some patients do not experience any other symptoms at all besides the visual disruption.
Common symptoms accompanying visual snow include:
- Ear pressure
- Concentration problems
- Head pressure
- “Dimmed” vision
Various treatments, both natural and pharmaceutical, can be used to manage or decrease the symptoms. Sometimes, easing the symptoms can ease the effect of the visual snow. However, getting a diagnosis can be difficult, especially if the accompanying symptoms get more attention than the visual disturbance.
Getting a Diagnosis
Getting a firm diagnosis of visual snow is difficult. Underlying causes, comorbidities, and overwhelming accompanying symptoms can overshadow the actual condition and it can be missed. There are also other unrelated conditions that can be confused with visual snow syndrome.
While ophthalmologists, neurologists, and general practitioners can diagnose visual snow, a neurologist is often more likely to identify and diagnose the condition. In order to obtain the initial diagnosis the patient must meet four key criteria:
- Have continuous, dynamic dots in the vision field
- Must exhibit at least one additional symptom:
- Palinopsia (after images and visual trailing)
- Tinnitus (buzzing or ringing in the ears)
- Enhanced entoptic phenomena (blue field entoptic phenomenon, floaters, self light of the eye, photopsia)
- Impaired night vision
- Symptoms are not associated with standard migraine aura
- Symptoms are not associated with another medical condition or disorder such as drug abuse, MS, ophthalmological disease, or others.
Common Linked Conditions
There are several medical conditions that are commonly linked to visual snow. These conditions may be comorbid with VS or the condition may be a symptom. These conditions are:
- Persistent migraine aura (PMA) – A migraine aura is a disturbance that can precede a migraine or accompany it. Often these auras are visual and the patient may experience flashes of light, flares, or other vision disruptions. A typical migraine aura is relatively short, lasting a few minutes to an hour. However, in a PMA the aura can last for days, even extending beyond a week.
- Hallucinogen persisting perception disorder (HPPD) – With this disorder the patient experiences sensory disturbances, often visual, that are the result of the patient using hallucinogenic drugs such as LSD even in cases where they have not taken the drug for years. This condition is often referred to as “flashbacks.”
- Optic neuritis from Multiple Sclerosis (MS) – This condition occurs when the optic nerve becomes inflamed and loses the myelin (coating that protects the nerve). As a result, the unprotected nerve does not work as it should, and it cannot send the right messages to the brain. This can lead to visual disturbances such as visual snow.
- Brain Injury (BI) – A traumatic brain injury or head injury can occur when the patient’s head is jerked or jostled, or they suffer a blow to the head. Depending on the location and severity of the injury, the patient may experience visual disturbances as a result.
Effects of Visual Snow
Many patients who live with visual snow don’t experience much of an impact in their lives due to the condition. Often they have had the condition since childhood and to them it is normal. They have created adapting strategies that allow them to compensate for the impaired vision and they can carry on their daily lives with few disruptions. However, some patients experience significant problems because the condition impairs their vision and creates incredible stress. In those cases, doctors and patients alike consider visual snow to be a debilitating condition.
A patient with VS may experience impaired vision and this alone can be stressful. When they have to manage it every day, many patients can become depressed or anxious about it. They may experience sensitivity to light, sometimes severe, and night blindness. These difficulties can lead the patient to become socially withdrawn and isolated which does not help if they are experiencing depression.
This powerful video shows how one woman perceives her struggle with visual snow:
Treatments for Visual Snow
There are very few treatments for visual snow. In most cases, treatment depends on the underlying condition or associated condition if there is one. There is no single treatment that works for all or even most patients with VS. Often, once the doctor diagnoses the condition he or she will have to work with the patient, trying various treatment methods until they find something that works. Most VS treatment options are theoretical and not proven through extensive clinical testing, yet many patients attest to their effectiveness.
Some of the more common treatments include:
Precision Tinted Glasses – Precision tinted glasses, or migraine glasses, have helped many people find relief. While they are not a recognized treatment method for visual snow, many patients claim that their migraine glasses made all the difference. Migraine sufferers use these glasses, while similar glasses are used by patients with Irlen Syndrome (a disorder of perceptual processing of visual information) and light sensitivity.
Vision rehab – This is a term that applies to several strategies including visual adaptation and visual habituation which have been found very useful in treating patients who have visual vertigo. While it is not yet proven to provide relief for VS, it is a theory that some doctors feel is worth pursuing.
Medication – Medication is usually administered to treat the cause of visual snow when there is an underlying condition. In some studies, medications such as propranolol and lamotrigine have provided some relief.
Diet – Diet can be key in a variety of health conditions and those involving the eyes and brain are no different. Visual snow can result from a patient’s reaction to dietary issues, particularly sensitivities to preservatives in foods. The first steps a patient can take in getting better is to modify their diet to avoid processed foods.
How to Help Someone Suffering from Visual Snow
If you have a friend or family member who suffers from visual snow, then you probably know the difficulties that they have on a daily basis. The best way to help someone with this condition is to educate yourself. Find out what visual snow is and how it specifically affects that person. Learn about what makes it worse and what lessens the symptoms. Don’t be afraid to ask questions to better understand how you can help the person.
Keep in mind that the patient cannot control their condition and they likely cannot control any underlying or additional symptoms that they may have. Try to be understanding and sensitive to the fact that they may experience anxiety and depression as a result of the condition.
If you are an employer and you have an employee who has visual snow, education is where you need to start. Ask the patient how their VS affects them and how it affects their work. Ask them if they require any reasonable accommodations to make their work environment more comfortable and more productive. Understand that there are many conditions that accompany visual snow, including anxiety, panic attacks, migraines, and other health issues.
What patients experience when they have visual snow is as real and valid as other health conditions. They deal with symptoms as well as a sense of being different and sometimes failing to fit in with their peer groups. Any disability can be isolating and VS is no different, especially when it is severe. Patience and a desire to understand will help patients relax and help them fit in and experience the world in a much more pleasant way.
If you have Visual Snow
If you have visual snow syndrome or think you do, you can get relief. Talk to your doctor or healthcare professional about the various therapies and treatments that are available for your specific situation. Doctors and researchers are making progress every day in treating patients with VS, whether it is a condition on its own or the symptom of an underlying condition. Most of all, take care of yourself. When you are dealing with any health issue the first step to getting better is self care. Make sure that you eat healthy, exercise regularly, stay hydrated, and get plenty of sleep.
Many visual snow patients find comfort and support in a number of online groups and forums.
If you have this condition you may enjoy connecting with other visual snow patients on these sites:
What’s Ahead for Patients?
There could be great things ahead for visual snow patients as new research is looking into treatments and cures for the condition. The Eye on Vision Foundation (EOVF) is a 501(c)3 non-profit organization that is devoted to finding a cure for visual snow and related conditions. The EOVF founder, Jennifer Ambrose, is a sufferer of VS and it has had a significant impact on her life. She has had it since childhood, but the symptoms increased in intensity in 2005 to the point that it affected her quality of life. Her symptoms, which had calmed some since her initial diagnosis, came back with a vengeance in 2014, and she is still very much affected. She hopes that the research funded by her foundation will open new doors to provide help and relief for visual snow patients. Most of all, she is looking for a cure.
Two neurologists have been collaborating with EOVF to find a treatment for visual snow. Dr. Peter J. Goadsby and Dr. Christoph J. Schankin conducted the first visual snow study, publishing the results in May 2014. They believe that this study helped them identify the area of the brain where VS originates. Dr. Schankin led a German visual snow study in 2015 – 2017.
Visual Snow 2019 Update
Several recent studies have shed more light on the causes and effects of visual snow. As researchers learn more about the condition, they are better able to develop treatments that are more effective and may even lead to a cure.
A common complaint among patients with visual snow syndrome is the significant difficulty in getting a diagnosis. It is often quite difficult for doctors to detect any problem at all because brain imaging, as well as ophthalmological and neurological clinical examinations, come back as normal.
This has led some doctors to view the condition as psychogenic or malingering instead of a valid medical condition. This, in turn, causes a great deal of stress and frustration for the patient because they walk out of the doctor’s office with no answers, only more questions.
The majority of visual snow patients also have migraine with or without aura. Some doctors naturally make the link between the visual snow and migraine, labeling it as “persistent migraine aura.” The problem is, migraine treatments are not helpful in treating the condition.
In this study, there were three groups:
- 18 patients with visual snow syndrome
- 18 patients with migraine (age-matched to the visual snow group)
- 18 patients who were healthy controls (no migraine or visual snow)
At the conclusion of the study, researchers determined that visual snow is a neurologic condition – and it is very real. Patients who have visual snow are not malingerers. They are not faking their symptoms. They are experiencing real symptoms that come from a disorder of the brain’s visual postprocessing system. It is not migraine and definitely not persistent migraine aura. However, they did find that in patients who had both visual snow and migraine, their visual snow is more severe.
While it is very common for patients with visual snow to have migraine, the researchers could find no evidence that it actually causes migraine.
In this study, there were 29 participants:
- 10 visual snow with migraine
- 7 visual snow without migraine
- 12 healthy control group
There is still so little known about visual snow and scientists are still trying to pin down a more exact or accurate pathophysiology. The researchers utilized neurophysiological assessments to examine cognitive function and response, specifically in the occipital cortex. Their goal was to identify how these responses differ among visual snow patients with migraine and those without migraine, as well as those in the healthy control group who did not have visual snow or migraine.
One of the most striking results of the study was in the way the participants handled the stimuli. Those with visual snow reported floaters and flickering, as well as other symptoms. Those in the healthy control group did not report any symptoms.
What is most notable is that the participants in the healthy control group were able to habituate. The stimuli no longer bothered them. The participants in the two visual snow groups were unable to habituate or experienced a significant decrease in their ability to do so. This seemed to make the symptoms even more distressing.
This review analyzed literature on studies and research of visual snow. The purpose was to attempt to better identify potential causes of the condition and gain a better understanding so that doctors can do better at treating it.
The researchers determined that there are likely a number of factors that contribute to the development of visual snow syndrome. Cortical hyperexcitation and subcortical network malfunction were at the top of the list. Their review also presented substantial evidence that the abnormalities of processing were separate in each group which supported the assertion that migraine and visual snow are separate conditions.
One potential (and likely) cause cited was sensory misperception stemming from a significant disturbance of sensory processing. While other conditions share this symptom, migraine included, the evidence points to the conditions being separate. This could lead to more effective treatments and will definitely encourage further investigation.
Researchers across the globe are planning more studies to better understand and find treatment for this condition. The hope is that one day there will be a cure and that people suffering from visual snow will get relief and have the chance to live a better quality life.
Hope is on the horizon.