A 13-year-old girl had had two grand ma1 attacks induced by viewing television when she was aged 10 and 11 years, and again a year later. Clinical and electroencephalographic (EEG) findings were typical of photosensitive television epilepsy. However, a further grand ma1 seizure when the patient was age 13 years occurred in darkness. Two additional EEG studies showed continuous paroxysmal activity during darkness. The epileptiform discharges were abolished by light and eye opening.