To study the effects of anti-oxidant on tear film parameters in patients with diabetes mellitus, a total of 100 patients of diabetes mellitus with defective Schirmer test and tear film break-up time were enrolled in this study and they were given vitamin C (1000 mg/day) and vitamin E (400 IU/day) for 30 days. Schirmer test and tear break-up, time were re-examined after 1 month. There was significant improvement in values for Schirmer test (p < 0.001) and tear break-up time. Oxidative stress has an influence on how diabetes mellitus affects various systems of body. This study clearly depicted im- portant roles of vitamins C and E in improving the well-being of the ocular surface.