This study on cataract surgery without preoperative topical mydriatics: in patients with type-2 diabetes mellitus was undertaken in the department of ophthalmology, in a tertiary care centre.The study was performed in 61 patients. The duration of diabetes mellitus in each patient was noted. Preoperative examination was done 3 days before the scheduled phacoemulsification procedure. The BP and the pulse was recorded of each patient. After dilatation of pupil (tropicamide 0.8% and phenylephrine hydrochloride 5%) patient was taken to the operation theater for the measurement of the pupillary size. The BP and the pulse was measured again. A surgical caliper was used to measure the size of pupil.No topical mydriatics were used on the day of the surgery. The BP and pulse of the patient was recorded again .All surgeries were performed by a single surgeon. The horizontal diameter of pupil was measured under operating microscope with caliper. The intensity of the microscope light was keptconstant throughout the procedure. 90 sec after injection of 1% lignocaine in the anterior chamber horizontal diameter of pupil was measured again and noted.