Comparing between Frequency Doubling Perimetry and Standard Automated Perimetry to evaluate the sensitivity of both instruments in early detection of field changes in diabetic patients.FDP was found to be more sensitive regarding mean deviation and pattern standard deviation especially in diabetic patients with normal fundus. Also the FDP was found to be more sensitive in control group regarding the pattern standard deviation but the sensitivity of FDP started to change in other subgroups . While by comparing the results to control, it was obvious that there is high sensitivity with significant value in both SAP and FDP but this sensitivity was higher in FDP in almost all the subgroups of diabetes.