What is Visual Snow Syndrome?
Visual snow syndrome is a rare neurological visual processing disorder that causes visual disturbances. It affects the entire visual field. Continuous, tiny flickering dots is the classic symptom of visual snow, also referred to as visual static.
The prevalence of people living with visual snow is unknown, but experts believe it is more common in late adolescence and early adulthood. Visual snow is linked to migraine with aura. However, there is no evidence that one condition causes the other.
There are alternate medical names for visual snow syndrome including:
- Visual static
- Scotopic sensitivity syndrome
- Visual stress
- Persistent Visual Phenomena
What Causes Visual Snow?
The exact cause of visual snow syndrome is unknown. It is not associated with structural changes in the eye.
However, neurological experts believe it is rooted in the visual pathway becoming "hyper-excited" to internal and external visual stimuli.2
Visual snow syndrome has been linked to a cortical brain dysfunction called thalamocortical dysrhythmia. This disorder is a miscommunication of neurons (brain signals) between the thalamus (relay station of incoming motor and sensory information) and the cerebral visual cortex (responsible for complex brain functions).
Magnetic encephalography testing (MEG) confirmed the brain changes involved in thalamocortical dysrhythmia and visual snow.
Signs and Symptoms of Visual Snow
Most people experiencing visual snow have the classic symptom of seeing many tiny, flashing dots in their field of vision.
People have stated that it resembles looking at static on an analog television. While the tiny dots typically appear black and white, some people report the dots are colored.
While there aren't visible signs of visual snow syndrome (no structural changes), symptoms can be physical and visual.
Various non-visual and psychiatric symptoms are present with visual snow syndrome:
- Migraine headache is a debilitating throbbing headache on one side of the head causing nausea, vomiting, and light sensitivity
- Tinnitus is ringing of the ears
- Persistent postural perceptual dizziness (PPPD) is chronic dizziness without nausea
- Anxiety and depression are common symptoms of people experiencing visual snow syndrome
- Fatigue and poor sleep quality are side effects of visual snow symptoms
- Fine motor tremors or uncontrolled movement of the hands
Additional visual symptoms of visual snow syndrome include:
- Light sensitivity (photophobia)
- Impaired night vision (nyctalopia)
- Seeing images that are no longer there (palinopsia)
- Flashes of light (photopsia)
- Floaters in the field of vision
- Enhanced entoptic phenomena (visual images from within the eye, not the outside world)
Risks and Complications of Visual Snow
While visual snow syndrome will not progressively get worse, it is a chronic condition that will not go away on its own. Untreated visual snow syndrome is not a cause of blindness.
However, it is a debilitating eye condition that, if left untreated, can negatively affect the quality of life, mental health, and how you function.
People with these conditions are at a higher risk of developing visual snow syndrome:
- Migraine with aura
- Hallucinogen persisting perception disorder (after using illicit drugs)
- Autism spectrum disorder
- Use of hallucinogenic drugs
- Family history of visual snow or migraines
How is Visual Snow Diagnosed?
Visual snow syndrome can be tricky to diagnose because it is often confused with other neurological or eye disorders, including:
- Persistent migraine aura
- Eye floaters
- Retinal detachment
To rule out other health conditions, a healthcare provider will:
- Take a detailed family and medical history
- Ask about visual and sensory symptoms
- Conduct a physical examination
- Administer a neurological exam
- Refer for normal ophthalmology tests (comprehensive eye exam)
- Order a computed tomography (CT) or magnetic resonance imagining (MRI) scan
A formal visual snow diagnosis will be made when “snow” or “static” symptoms persist for longer than three months and if you experience two or more of the following symptoms:
- Light sensitivity
- Trouble seeing at night
- Seeing images or objects that are no longer there
- Excessive floaters in both eyes
- Not responding to migraine medication
- Other health conditions have been ruled out
How Do You Get Rid of Visual Snow?
Since medical experts don't know much about what causes visual snow syndrome, there are few treatment options available.
The primary goal of treating visual snow syndrome is minimizing symptoms and improving quality of life. Doctors may recommend the following treatment options:
- Use dull-colored paper
- Avoid bright reading lights
- When reading and writing, use a bookmark to avoid line skipping
- Tinted glasses (such as FL-41 lenses) may reduce the effects of visual snow
- Anti-seizure medication (lamotrigine)
- Nerve-pain medication (nortriptyline)
- Over-the-counter pain medication (naproxen)
- Antidepressant medication (sertraline)
While medication may be prescribed for people with visual snow syndrome, they have not proven to be effective at treating symptoms and many come with notable side effects.
Visual snow syndrome isn't a progressive condition, and chances are it won't get worse. However, it is a chronic condition, and a lack of treatment options makes it difficult to minimize symptoms and prevent flare-ups.
Living with visual snow syndrome can impact quality of life and mental health. A person diagnosed with visual snow syndrome may have a multidisciplinary team of doctors that includes a neurologist, psychologist, and ophthalmologist (eye doctor).
Visual snow syndrome is a rare chronic neurological disorder resulting in tiny, flashing dots appearing in your entire visual field, similar to static or snow. It is often misdiagnosed and may accompany certain health conditions, including; migraines, tinnitus, and dizziness.
Medical experts don't know much about visual snow syndrome, so treating symptoms can be tricky. General treatment includes anti-seizure medication and tinted glasses. However, treatment is not effective for everyone.
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