Flickering television, VDUs and strobe disco lights are known to provoke epileptic fits in sensitive people. There is also a possibility that video games and virtual reality units could aggravate the risk of seizures.
15,000 of the 300,000 people with epilepsy in the UK have the photosensitive kind. After each showing of a cartoon featuring strobe-light in Japan, 700 viewers suffered epilepsy-like seizures, muscle spasms and nausea.