Background: Diabetes mellitus is one of the major health issues affecting people across nations. The complications of diabetes mellitus affect vital organs of human body, among which eyes are more susceptible to diabetic complications like primary open angle glaucoma. Increased IOP is one of the complications faced by diabetics. Aim: to compare the intraocular pressure in diabetes mellitus and non diabetic’s individuals. Material and methods: This prospective observational study was done the Department of Ophthalmology, Nalanda Medical College and Hospital, Patna, Bihar, India, for 1 year. all the Patients having diabetes mellitus on treatment and Non diabetic individuals was included in this study. Two groups were formed which includes Group A constituting diabetes mellitus patients and Group B constitutes Non diabetic individuals. Detailed history of diabetes mellitus patient was taken regarding duration of diabetes, treatment, fasting, post prandial blood sugar levels and HbA1c was recorded. Intra ocular pressure was compared between Group A and Group B, to correlate intra ocular pressure in relation to duration of diabetes mellitus and different stages of diabetic retinopathy. Diabetic retinopathy changes were classified according to the ETDRS classification. Results: 140 patients were included in our study. 60 patients had Type 2 diabetes mellitus (all were non insulin dependent) and 10 patients had Type 1 diabetes mellitus, and 70 patients were Non-diabetics subjects. Mean age of non diabetics was 53.7±12.1 years and that of diabetics 58.12±11.63 years (p valve 0.43) statistically not significant. In those 70 diabetic patients 50 were male and 20 were female. Mean age of male subjects was 57.96±10.3 years and that of female was 58.09±11.32 years in diabetic group which was no statistically significant (p value 0.47). The mean intra-ocular pressure higher (16.89±2.39mmHg) in diabetic patients as compared with (13.93±2.86mmHg) in non-diabetic, p value < 0.0001 which is statistically significant. Conclusion: This study shows significantly higher intraocular pressures in patients with Type 2 diabetes. This would suggest that diabetics should be monitored regularly for intraocular pressure to detect an early onset of glaucoma in susceptible patients.