Abstract Aim: The aim of the present study was to compare the intraocular pressure in diabetes mellitus and non diabetic’s individuals. Methods: This prospective observational study was done the Department of ophthalmology in Jawahar Lal Nehru Medical College and Hospital, Bhagalpur, Bihar, India, for 1 years. This research involved all diabetic and non-diabetic patients with diabetes mellitus who were on care. Patients with diabetes mellitus were divided into Group A, while non-diabetic people were taken into Group B. A comprehensive history of the patient's diabetes mellitus was taken, including the length of the condition, medication, fasting, postprandial blood sugar levels, and HbA1c. Intraocular pressure was compared between Groups A and B to see whether there was a correlation between intraocular pressure and diabetes mellitus duration and different stages of diabetic retinopathy. Results: 150 patients were included in our study. Mean age of non diabetics was 52.6±11.9 years and that of diabetics 56.19±11.93 years (p valve 0.37) statistically not significant. In those 75 diabetic patients 53 were male and 22 were female. Mean age of male subjects was 58.16±11.3 years and that of female was 57.79±11.82 years in diabetic group which was no statistically significant (p value 0.38). The mean intra-ocular pressure higher (17.09±2.59mmHg) in diabetic patients as compared with (14.03±2.76mmHg) in nondiabetic, p value < 0.0001 which is statistically significant. The mean intra ocular pressure was (17.18±2.63mmHg) in diabetic patients with duration greater than 10 years as compared with (17.08±3.37mmHg) in diabetic patients with duration less than 10 years, p value > 0.05 which is not significant. The mean intra-ocular pressure (18.52±2.87 mmHg) higher in diabetic patients with HbA1c value >6.5% as compared (17.17±1.63 mmHg) with diabetic patients with HbA1c value <6.5%, p value < 0.0005 which is statistically significant. Conclusion: Diabetes mellitus is a risk factor for IOP. The rise in IOP is prevented by strict glycemic regulation. IOP was shown to be more likely in patients with impaired glycemic function. Diabetic patients should have their IOP tested on a daily basis to reduce the burden of glaucoma-related ocular morbidity.