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 Empire Innovator Scholar 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 Visual Snow Patients?
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 SnowThere 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 sub-types 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)
Causes of Visual SnowDoctors 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 and other areas of the brain’s cortex. 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 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 to visual snow include:
- Sleep deprivation (insomnia, fatigue)
- Lyme disease
- Auto Immune disease
Other Accompanying SymptomsMigraine, 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
Getting a DiagnosisGetting 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 optometrists, 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, or others.
Common Linked ConditionsThere 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 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 SnowMany 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 as 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 show’s how one woman perceives her struggle with visual snow.
Treatments for Visual SnowThere 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:
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.
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 and use these glasses while similar glasses are used by patients with Irlen Syndrome and light sensitivity.