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Abstract This thesis presented a visual evoked potential (VEP) which is electrical potential obtained from optic tract as a response to visual external stimulation induced by light. There are two types of VEP: Flash visual evoked potential (FVEP) and Pattern reversal visual evoked potential (PRVEP). The aim of this study was to evaluate the effect of change of wavelength of flash and change of visual angle on the parameters of visual evoked potential (VEP) (latency and amplitude). The present study was conducted on thirty individual. The subjects were divided into two groups: group one is consisted of twenty healthy individual, second group is consisted of ten glaucoma patients. Flash (blue and white) VEP with 2HZ and visual angle of (15’, 30’, 60’ and 120’) of pattern reversal VEP were done for all subjects. As a result, monochromatic blue flash VEP was preferred than white as there were minimal coefficient of variation (COV) of inter-individual and intra-individual variation of latencies and amplitudes. While in PRVEP, the latency was decreased with increase of check size and the amplitude was increased when the check size increase. The optimum check size was 120’ which produced the best result. |