We studied the differences in latency and amplitude between the laser stimulated visual evoked potentials (VEPs) and the cathode-ray tubes (CRTs) stimulated VEPs to estimate the risk of inducing photosensitive epilepsy by laser displays. Twenty healthy subjects were recruited for the study. Red and blue light stimulations were flashed in 1, 7.5 and 15Hz. The latency of P1, N1, P2 and N2 in 1 Hz stimulation revealed no significant difference by a paired t test between laser and CRT stimulation. The peak-to-peak amplitude was significantly smaller with red or blue laser stimulation than with red or blue CRT stimulation, for PI-N1 and N1-P2 at 7.5Hz stimulation, and for N1-P2 and P2-N2 at 15Hz stimulation. We therefore postulate that laser does not produce more excitability to occipital cerebral cortex than CRT does. There was no evidence to say that laser stimulation is more dangerous as the risk of inducing photosensitive epilepsy than conventional CRT stimulation
