Seizure Disorders

Seizure disorders are a class of neurological disability where the brain experiences a higher-than-usual amount of electrical activity 1.

Symptoms of seizures include temporary confusion, staring, muscle spasms and uncontrollable jerking, loss of consciousness, and cognitive or emotional symptoms 2.

Photosensitive epilepsy is a specific seizure disorder 3. People with photosensitive epilepsy can have a seizure triggered by flashing lights, bold, regular patterns, or moving patterns 3. Often the trigger involves brightness and darkness, such as black and white stripes, flashing lights in a dark space, etc 3.

Design Considerations

Under no circumstances should we ever knowingly cause our users to lose consciousness or convulse.

While we can’t guarantee that our designs will never cause seizures, things we can do include:

  • Avoid video, animations, or transitions with flashing light sequences of 3 times or more per second 4.
  • Avoid bold, contrasting visual patterns such as stripes or checks 3.
  • Avoid creating stimulating images that take up the complete field of vision 3.

Additional Resources


  1. Photosensitive Epilepsy on WebMD[]
  2. Seizures on Mayo Clinic[]
  3. Photosensitive epilepsy on Wikipedia[][][][][]
  4. Accessibility Fundamentals – Disabilities, Guidelines, and Laws at Deque University[]