Chronic hyperglycemia is one certain cause of diabetic retinopathy. VEP findings may identify pathology in both early and late stage diabetes. Present study was done to evaluate the effect of acute rise in blood sugar on visual evoked potential in normal subjects. Subjects aged between 17yrs -21yrs of both sexes (n=100) were selected for the study. First recording of VEP done then measurement of capillary blood glucose level done prior to administration of 50 Gm Glucose then repeat measurement done after ½ hour. After rise of capillary blood glucose level recording of VEP was done. Latency of N75 and P100 along with amplitude of N75-P100 has been analysed. Amplitude of N75-P100 has statistical significant difference with p-Value of 0.0054 for right eye and 0.0039 for left eye. Sudden rise of blood sugar level certainly affects result of VEP even in non-diabetic persons. To avoid wrong interpretation of VEP findings every physiologist should consider this post-prandial effect of increased blood sugar while doing VEP in diabetic as well as non-diabetic.