Photic hazards at work and at leisure [epileptic EEG discharges]

Photosensitive epilepsy occurs in approximately 1 in 4,000 of the population (Harding and Jeavons, 1994). Relatively few seizures are precipitated by natural phenomena such as sunlight through trees, or reflected from surfaces such as water or snow. It has long been recognised that in Europe the television monitor is the most common precipitant of photosensitive seizures (Harding and Jeavons, 1994) whether the monitor is used for broadcast, video or computer game material (Harding et al., 1994). Other sources of provocative stimuli in the urban environment are discotheques, cinema (“Titanic”) light off shiny surfaces in supermarkets, sunlight through tress, chimneys and railings whilst travelling and patterns such as bars on the stairs of escalators. Recently the importance of pattern sensitivity has been recognised, less commonly in the environment but particularly when combined with TV presentation (Harding et al., 1994)