Photosensitivity is defined by the appearance of occipital or more diffuse electroencephalographic spikes and waves induced by intermittent light stimulation (ILS), particular patterns, TV-watching, and video games. Photosensitivity is a genetic characteristic. Only the diffuse spikes and waves induced by ILS are correlated with epilepsy. Pure photogenic epilepsy is characterized by seizures which are only visually induced, usually by watching TV. Video games sometimes add a trigger effect due to slowly moving patterns or intense brightness. Several epileptic syndromes are associated with a photosensitivity with or without visually-induced seizures, mainly generalized idiopathic epilepsy.