Visual Snow Syndrome: Symptoms, Causes, And Treatment

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What Is Visual Snow Syndrome?

Medically reviewed by Susan W. Lee, DO — Written by Daniel Yetman on September 7, 2022

Symptoms
Causes
Risk factors
Diagnosis
Treatment
FAQs
Takeaway

Visual snow syndrome involves flickering dots in your field of vision. It’s unclear what causes it, but experts suspect it has neurological origins.

Times Square in New York City as seen by someone with visual snow syndrome — Alexander Spatari (street), bunhill/Getty Images (static); Design by Erica Singleton

Visual snow syndrome is a recently discovered neurological disorder that received its name in 2013.

It’s characterized by flickering dots across your entire field of vision. These dots resemble “snow” or static — the pattern on the screen of an analog television when it’s not set to a channel.

Researchers knew very little about visual snow syndrome until the late 2010s. It’s still not clear how common it is or what causes it. Brain imaging studies have suggested that it may be related to problems with one or more parts of the brain.

Some researchers think that visual snow might go unnoticed in many cases because the brain edits it out. For some people, visual snow can be debilitating and seriously affect their quality of life.

Read on to learn more about visual snow syndrome, including symptoms, causes, and treatment options.

What are the symptoms of visual snow syndrome?

The main symptom of visual snow syndrome is visual snow, the persistent flickering of dots across your entire visual field, resembling television static. Visual snow is usually black and white but can be:

colored
flashing
transparent

Up to 75% of people with visual snow syndrome also report at least three of the following symptoms:

palinopsia, or seeing an after-image of objects after they’re gone
light sensitivity
impaired night vision
enhanced entoptic phenomena, or visual changes originating from within the eye that might cause:
- floaters in both eyes
- blue field entoptic phenomenon, seeing squiggly lines when looking into bright blue areas like the sky
- self-light of the eye, colored waves or clouds when eyes are closed in a dark space
- spontaneous photopsia, bright flashes of light

What causes visual snow syndrome?

The cause of visual snow syndrome is still largely unknown. Experts think it may be a neurological disorder of the brain’s visual processing center.

In particular, dysfunction and excessive activity of neurons in two parts of the brain may play a role:

the primary visual cortex, which processes visual information
the lingual gyrus, which plays a role in editing visual information for your brain to interpret

The exact area of brain involvement might vary slightly between people. This may also explain why people experience different symptoms.

In early studies, researchers found people with visual snow syndrome generally had typical scores on eye exams. People are usually young when they develop visual snow syndrome. It often seems to develop in childhood.

Some people develop visual snow syndrome after

taking medications
brain trauma
infection

Much of what’s known about the causes of visual snow syndrome is limited to individual case studies. For example:

A 2021 case study documented the first case of visual snow syndrome developing after COVID-19 infection.
In a 2022 case study, researchers presented a case of visual snow syndrome developing after LASIK surgery.
Another 2022 case study reported visual snow syndrome in a person who experienced a series of mild concussions.
Another 2022 case study reported probable visual snow syndrome related to methylphenidate to treat a child with attention deficit hyperactivity disorder (ADHD).

What are the risk factors for visual snow syndrome?

In a 2020 study of a group of 1,100 people with visual snow syndrome, the average age was 29. About 40% of people in the study had symptoms for “as long as they could remember.”

The researchers found no difference in how common visual snow syndrome was among the sexes. But those who identified as female had more severe cases.

Visual snow syndrome appears to be highly related to migraine. This suggests that there might be a possible shared mechanism. Nearly 75% of people with visual snow syndrome have a history of migraine.

About 25% of people with visual snow syndrome have severe depression or anxiety.

Visual snow and tinnitus

Tinnitus is a persistent ringing in the ears without an external sound. It’s quite common, possibly affecting about 10% of the general population.

Up to three-quarters of people with visual snow syndrome also have tinnitus. Some researchers think that there might be a relationship between the two conditions.

How do doctors diagnose visual snow syndrome?

Visual snow syndrome isn’t well recognized and is often misdiagnosed as persistent migraine aura.

Tests used to diagnose visual snow syndrome can include:

physical exam
eye exam
neurological exam

To diagnose you with visual snow syndrome, a doctor would need to decide that you meet the following criteria:

visual snow lasting longer than 3 months
at least one of the following four additional symptoms:
- palinopsia
- enhanced entoptic phenomena
- impaired night vision
- light sensitivity
symptoms not consistent with migraine visual aura
symptoms that are not a more likely sign of another disorder or caused by psychotropic drugs

A doctor would also need to exclude any conditions that cause similar symptoms.

Visual snow syndrome vs. migraine with visual aura

Most people with visual snow syndrome also report migraine. Doctors sometimes misdiagnose visual snow syndrome as migraine with visual aura. But there are some key differences.

Migraine with visual aura	Visual snow syndrome
is temporary	is more consistent
occurs before or during a migraine episode	may occur unrelated to migraine
moves slowly across visual field	is static (doesn’t move in any direction) in entire visual field

People with visual snow syndrome also tend to have additional visual symptoms not associated with migraine.

It’s important for doctors to be able to tell the two conditions apart. Migraine treatments typically do not help with visual snow syndrome.

What is the treatment for visual snow syndrome?

No current treatment has proven effective for treating visual snow syndrome. Researchers are continuing to investigate potential options.

Current evidence suggests the medications that prevent migraine, such as antidepressants or pain medications, don’t consistently improve or worsen visual snow syndrome. One single case study found potential benefits with the drug lamotrigine.

Recreational drugs and alcohol can worsen symptoms, at least temporarily.

Transcranial magnetic stimulation (TMS) is under investigation as a potential treatment. Some research suggests it may be beneficial, but larger studies are needed to fully explore its use. TMS uses magnetic fields to stimulate neurons in your brain.

There is interest in the use of tinted lenses to improve symptoms of visual snow syndrome.

Frequently asked questions

Here are some frequently asked questions people have about visual snow syndrome.

Can visual snow syndrome cause blindness?

Visual snow syndrome isn’t usually progressive and does not lead to permanent blindness.

Some conditions that cause similar symptoms can cause vision loss. You’ll need a proper evaluation to rule these out.

Can I drive with visual snow syndrome?

The level of visual impairment varies significantly among people with visual snow syndrome. Many people can continue to drive if visual snow isn’t impairing their ability to see.

But people with severe symptoms or impaired night vision may not be able to drive safely or legally.

Does visual snow syndrome go away?

Visual snow syndrome is unlikely to go away by itself. As of now, there’s no cure, but a doctor can help you manage your symptoms.

How common is visual snow syndrome?

It’s not clear how common visual snow syndrome is. One study estimated that about 2% of people in the United Kingdom might have it.

But the people in the study were self-recruited, so there’s a good chance that this estimate is too high.

Takeaway

Visual snow syndrome is a neurological condition in which persistent dots appear in your visual field, resembling television static.

Researchers don’t know exactly what causes it, but they think that problems in the visual processing centers of your brain may play a role.

As of now, there’s no cure for visual snow syndrome. Still, a proper evaluation is important to rule out other conditions that can cause permanent vision loss.

Researchers continue to explore new treatment options.

How we reviewed this article:

SourcesHistoryHealthline has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical journals and associations. We only use quality, credible sources to ensure content accuracy and integrity. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

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Ciuffreda KJ, et al. (2021). Visual snow syndrome: Evolving neuro-optometric considerations in concussion/mild traumatic brain injury.https://www.futuremedicine.com/doi/10.2217/cnc-2021-0003
Fraser CL, et al. (2022). Visual snow: Updates on pathology.https://www.researchgate.net/publication/358966292_Visual_Snow_Updates_on_Pathology
Grey V, et al. (2020). Can repetitive transcranial magnetic stimulation of the visual cortex ameliorate the state of patients with visual snow?https://pubmed.ncbi.nlm.nih.gov/32484702/
Hang C, et al. (2021). Not all cases of visual snows are benign: Mimics of visual snow syndrome.https://www.dovepress.com/not-all-cases-of-visual-snows-are-benign-mimics-of-visual-snow-syndrom-peer-reviewed-fulltext-article-NDT
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Naguy A, et al. (2022). Probable methylphenidate-related reversible “Visual Snow” in a child with ADHD.https://pubmed.ncbi.nlm.nih.gov/35713542/
Puledda F, et al. (2020). Visual snow syndrome: A clinical and phenotypical description of 1,100 cases.https://n.neurology.org/content/94/6/e564
Schankin CJ, et al. (2014). ‘Visual snow’ – a disorder distinct from persistent migraine aura.https://academic.oup.com/brain/article/137/5/1419/334357
Tinnitus. (2017).https://rarediseases.org/rare-diseases/tinnitus/
Visual snow syndrome. (2018).https://rarediseases.org/rare-diseases/visual-snow-syndrome/
Werner RN, et al. (2022). Case report: Visual snow syndrome after repetitive mild traumatic brain injury.https://journals.lww.com/optvissci/Abstract/2022/04000/Case_Report__Visual_Snow_Syndrome_after_Repetitive.16.aspx
White OB, et al. (2022). Editorial: Visual snow: Old problem, new understanding.https://www.frontiersin.org/articles/10.3389/fneur.2022.884752/full
Wood H. (2020). Shedding new light on visual snow syndrome.https://www.nature.com/articles/s41582-020-0324-8

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Medically reviewed by Susan W. Lee, DO — Written by Daniel Yetman on September 7, 2022

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