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Seizures are sudden electrical disturbances in your brain that cause temporary changes to your behavior and movements. Symptoms can vary in severity from unnoticeable to dramatic full-body convulsions.

The most common cause of seizures is epilepsy. Epilepsy is classified into many types depending on the type of seizures you experience and how they develop.

Somewhere between 2 and 14 percent of the 3.4 million people with epilepsy in the United States experience photosensitive epilepsy. Photosensitive epilepsy is when seizures are triggered by flickering or flashing lights.

Keep reading to learn more about photosensitive epilepsy, including potential triggers, symptoms, and preventative tips.

Photosensitive epilepsy is characterized by seizures triggered by flashing or flickering light. It’s most common in children and tends to become less common with age.

Video games and television are the most common triggers, but natural light sources can also trigger them. For example, some people may experience seizures after looking at sunlight shimmering through Venetian blinds or through leaves on a tree. For some people, images with highly contrasting or swirling colors can also trigger seizures.

Many people aren’t aware that they have photosensitive epilepsy until they have their first seizure. According to the Epilepsy Foundation, almost everybody with photosensitive epilepsy experiences their first seizure before the age of 20.

About 59 to 75 percent of people with photosensitive epilepsy are female, but males develop more seizures. One theory why this is true is because boys may play video games more often.

Photosensitive epilepsy can trigger several types of seizures, including:

Photosensitive epilepsy affects about 1 in 4,000 people. It’s especially common in children with genetic generalized epilepsy and certain syndromes like juvenile myoclonic epilepsy and Jeavon’s syndrome. Studies have found that between 30 and 90 percent of people with juvenile myoclonic epilepsy have photosensitive epilepsy.

Photosensitive epilepsy affects people in all ethnic groups. Some studies suggest higher rates among people of European and Middle Eastern descent and lower rates among people of African descent, but comparisons between studies are difficult.

The exact cause of photosensitive epilepsy remains poorly understood, even though many common triggers have been identified. Genetics seems to play a role in the development of photosensitive epilepsy. People with unique variations of the CHD2 gene have higher rates of photosensitive epilepsy than people in the general population.

Studies suggest that gamma waves that oscillate 30 to 80 times in the visual cortex may generate seizures in people with light-induced epilepsy, but more research is needed. Other research indicates that there are changes in the connections between different areas of the brain in people with photosensitive epilepsy.

Watching television and playing video games are the two most common triggers for photosensitive epilepsy. You’re more likely to develop seizures when exposed to brighter light sources.

Seizures most often occur in the presence of lights flashing 15 to 25 times per second, but the exact frequency varies between people. Red light is more likely to cause seizures than blue and white lights.

According to the Epilepsy Foundation, the following may trigger seizures:

  • quickly changing images that flicker on computer screens or television
  • video games that contain rapid flashes of light
  • strobe lights
  • sunlight shimmering off water or flickering through trees or blinds
  • highly contrasting visual patterns
  • possibly, flashing lights on emergency vehicles

What is unlikely to be a photosensitive trigger?

Triggers can vary between people, but the following are some examples of unlikely photosensitive triggers:

  • LCD screens
  • cell phones and devices with small screens
  • dimly lit screens
  • interactive whiteboards
  • lights that flash less than three times per second

When people think of seizures, they often think of tonic-clonic or grand mal seizures that cause loss of consciousness and uncontrollable muscle spasms. However, some types of seizures can be so mild that they’re barely noticeable.

Photosensitive epilepsy symptoms vary based on the type of seizure you have, but symptoms can include:

A doctor may diagnose you with epilepsy after you’ve had at least two seizures. To make the diagnosis, they will review your symptoms. They may want to speak with somebody who saw you have a seizure, since you may have been unconscious.

The doctor will also perform a neurological exam in which they check your reflexes, muscle strength, and posture.

An electroencephalogram (EEG) is often used in the diagnostic process. An EEG is a machine that measures the electrical activity of your brain and can record unusual patterns of electrical activity that may be a sign of epilepsy.

Imaging techniques like MRI and CT scans may be used to look for structural problems in your brain.

Treatment for photosensitive epilepsy primarily consists of taking antiepilepsy medications and avoiding triggers.


According to the Epilepsy Society, photosensitive epilepsy often responds well to seizure medications. You can work with your doctor to find the best medication and dosage for you.

Valproate is the preferred first-line medication for video game-related seizures. Studies have found it’s effective in preventing seizures in about half of people.

Preventing or avoiding seizures

If you’re sensitive to flashing or flickering lights, you may be able to prevent seizures by:

  • avoiding exposure to flashing light, and when that’s not possible, closing one eye and looking away from the source of the light
  • watching television in a well-lit room to reduce contrast
  • using LCD screens
  • avoiding watching television for long periods of time
  • sitting as far away as you can from the television
  • avoiding video games when you’re tired
  • taking frequent breaks when you’re on the computer
  • avoiding places where strobe lights are used, such as clubs and dances

It’s very important to see a doctor if you or a loved one develops a seizure for the first time. A doctor can help determine the cause of your seizure and build a proper treatment program.

It’s also important to call 911 or your local emergency services if you’re with a person who:

  • has a seizure longer than 3 minutes
  • does not wake up after their seizure
  • experiences repeated seizures
  • is pregnant and has a seizure

The outlook for photosensitive epilepsy varies among people but is generally good.

Photosensitive epilepsy is generally easy to treat with medication and by avoiding triggers. About a quarter of people stop having photosensitive seizures by age 30.

Photosensitive epilepsy is when you experience seizures after exposure to flashing or flickering lights. It’s most commonly triggered by watching television or playing video games, but it can also be triggered by natural light and static images with highly contrasting patterns.

If you think you may have had a photosensitive seizure, it’s important to visit a doctor for a proper diagnosis and assessment. Avoiding triggers is the only treatment needed for some people, but a doctor may recommend taking medications to keep seizures under control.