Diabetic retinopathy is one of the common complications of diabetes. Unfortunately, in many cases the patient is not aware any symptoms until it is too late for effective treatment. Through analysis of evoked potential response of the optical nerve and optical brain centre will pave a way for early diagnosis of diabetic retinopathy and prognosis during the treatment process. In this paper, we present a method to classify diabetic retinopathy subjects from changes in visual evoked potential spectral components.