Epilepsy Health Center

Photosensitive Epilepsy

People with photosensitive epilepsy have seizures that are triggered by:

• flashing light
• bold, contrasting visual patterns (such as stripes or checks)

Anti-epileptic medicines are available to reduce the risk of seizure. But people with photosensitive epilepsy should take steps to minimize their exposure to seizure triggers.

What Causes Epilepsy?

Epilepsy is a brain disorder that causes recurrent seizures (more than two). A seizure is caused by abnormal electrical activity in the brain.

Epilepsy may be the result of:

• irregularity in the wiring of the brain
• imbalance of neurotransmitters (chemical messengers in the brain)
• combination of these factors

In photosensitive epilepsy, genetics also plays a role.

About one in 100 people in the U.S. have epilepsy. About 3% to 5% of those people have photosensitive epilepsy.

Children and adolescents aged 7 to 19 are more likely to have photosensitive epilepsy. Girls are affected by the condition more often than boys. But boys tend to have more seizures. That's probably because they spend more time playing video games, a common seizure trigger.

What Causes Seizures in People With Photosensitive Epilepsy?

Seizure triggers vary from person to person. But some common triggers are:

• Flashing light
• Bright, contrasting patterns such as white bars against a black background
• Flashing white light followed by darkness
• Stimulating images that take up your complete field of vision, such as being very close to a TV screen
• Certain colors, such as red and blue

Some specific examples of situations or events that can trigger seizures in people with photosensitive epilepsy are:

• Nightclub and theater lights, including strobe lights
• TV screens and computer monitors
• Flashing lights on police cars, fire trucks, ambulances, and safety alarms
• Visual effects in movies, TV shows, and video games
• Malfunctioning fluorescent lights and moving escalators
• Light viewed through a fast-moving ceiling fan
• Sunlight viewed through slanted blinds or stair railings
• Sun shining through tree leaves or reflecting off water
• Bold, striped wallpaper and fabric
• Cameras with multiple flashes or many cameras flashing at the same time
• Fireworks

Also, people with photosensitive epilepsy may be at increased risk for a seizure if they are:

• Tired
• Intoxicated
• Play video games too long without a break

What Are the Symptoms of Photosensitive Epilepsy?

There are many different types of seizures. People with photosensitive epilepsy typically have what's called a "generalized tonic-clonic seizure." This is also known as a convulsive seizure.

A tonic-clonic seizure should last no more than five minutes. Symptoms include:

• Loss of consciousness and patient falls to the ground
• Muscles contract and body stiffens
• Patient cries out
• Breathing pattern changes
• Patient bites tongue and inside of cheeks
• Limbs jerk or twitch as muscles tighten and relax
• Loss of bladder control

When the seizure ends, the muscles relax and the person slowly regains consciousness. After the seizure, the person may:

• Be confused
• Feel tired
• Have memory loss for a short time
• Have a headache
• Feel sore

Recovery time varies. Some people are able to return to normal activity soon after a seizure. Others may need to rest.