Effectiveness of photic stimulation on various eye-states in photosensitive epilepsy

The photoconvulsive effect of photic stimulation on various eye states has been studied, in patients suffering from photosensitive epilepsy as well as in patients with epilepsy and photoconvulsive responses evoked by intermittent photic stimulation (IPS). Particular emphasis has been given to the state of eye-closure i.e. the state immediately following the closure of the eyes. Our findings indicate that IPS is more potent in eliciting photoconvulsive responses during the eye-closure state. IPS with the eyes open is more provocative than with the eyes closed or with monocular stimulation. Electroencephalographic abnormalities induced on eye-closure in the resting EEG are not evoked when eye-closure is performed in darkness, thus indicating that the light is the important factor in the causation of the above EEG abnormalities.