ABSTRACT-Reactive oxygen species (ROS) are products of normal cellular metabolism and are known to act as second messengers. Physiological conditions, ROS participate in maintenance of cellular 'redox homeostasis' in order to protect cells against oxidative stress through various redox-regulatory mechanisms. Oxidative stress resulting from enhances free-radical formation and/or a defect in antioxidant defences has been implicated in the pathogenesis of diabetes and its associated complications. Diabetes mellitus comprises a group of metabolic disorders that share the common phenotype of hyperglycemia, association with the biochemical alteration of glucose and lipid peroxidation. Increase level of oxidative stress along with deranging different metabolisms; one of the Long term complications of diabetes mellitus is diabetic retinopathy, which is a leading cause of acquired blindness. Many of the recent landmarks in scientific research have shown that in human beings, oxidative stress has been implicated in the progression of major health problems by inactivating the metabolic enzymes and damaging important cellular components, oxidizing the nucleic acids, leading to cardiovascular diseases, eye disorders, joint disorders, neurological diseases (Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis), atherosclerosis, lung and kidney disorders, liver and pancreatic diseases, cancer, ageing, disease of the reproductive system including the male and female infertility etc. In this review we have the importance of endogenous antioxidant defense systems, the intense medical management; these strategies include dietary measures (antioxidants) their relationship to several pathophysiological processes and their possible therapeutic implications in vivo condition.