Seizures
Seizure disorders cause sudden changes in the brain’s electrical activity. The kind of seizures and what causes them to decide which access barriers matter in both digital and physical places.
General seizure disorders
General seizure disorders can lead to various episodes. These can range from brief staring spells to convulsions. Often, these episodes don’t have clear triggers in the person’s environment.
Example
A person with generalised epilepsy may have a tonic-clonic seizure without any warning or clear cause. Their needs are more about staying physically safe, having good communication and avoiding too much information at once than about limiting what they can see or hear.
Photosensitive epilepsy
Photosensitive epilepsy happens when flashing or flickering images cause a seizure. Pictures that flash more than three times every second can trigger a seizure in people who are affected.
Example
A fast flashing ad on a news website could cause a seizure in someone with photosensitive epilepsy. This is why accessibility rules limit how fast things can flash and block some patterns.
Key point
Photosensitive epilepsy affects a small group of people with epilepsy. When it triggers a seizure, the effects are immediate and serious. This is one of the few accessibility problems that can cause real physical harm.