FOR MANY years it has been known that convulsive disturbances can be produced as a result of stimulation by visual, auditory, tactile, or other sensory stimuli. Two patients whose attacks were precipitated by bright light were described by Gowers in 1881.1 Other similar patients were discussed by Holmes2 and by Radovici, Misirliou, and Gluckman.3 The latter authors described attacks in a young man, consisting of rhythmic upward movements of the head, blinking of the eyes, and rotation of the head toward the sun's rays. Strauss4 reported on one patient in whom illumination of either eye by a flashing light caused a convulsion. It was noted that the flashing light was associated with 3-cycle-per-second (cps) waves of high voltage in the electroencephalogram. In reporting on three light-sensitive patients, Cobb5 drew attention to the importance of flickering light in contrast to continuous illumination as an epileptogenic agent.