Phacoemulsification with intraocular-lens implantation is the current surgical treatment of choice for cataract extraction. To prevent complications during surgery, there should be adequate pupillary dilation for better visualization of the posterior chamber. The objective of this study is to compare mean total loss of mydriasis with topical ketorolac tromethamine 0.5% and nepafenac 0.1% during phacoemulsification. The study design is randomized controlled trial and it was carried out in Department of Ophthalmology, Shaikh Zayed Hospital Lahore. The duration for this process is six months (August 2019 to January 2020). A total of 100 patients were selected from Ophthalmology Outdoor of Shaikh Zayed Hospital Lahore. The patients were randomly divided into two groups by lottery method, 50 patients in group A (Nepafenac 0.1%) and 50 patients in group B (Ketorolac tromethamine 0.5%). Five minutes later, tropicamide 0.5%, 1 drop every 15 minutes for 4 doses were instilled in both treatment groups. The two groups were compared with diameters of pupil was measured at different stages of cataract surgery and the mean values were compared across the two groups. The mean age of the patients in group A was 55.6±5.6 years and in group B was 54.6±5.7 years. The mean pupil diameter before surgery in group A was 7.9±0.4 and in group B was 8.0±0.5. The mean pupil diameter after surgery in group A was 6.4±0.6 and in group B was 5.7±0.5. The mean total loss of mydriasis in group A was 1.4±0.6 and in group B was 2.1±0.4. It is concluded from this study that Topical nepafenac has been shown to be a more effective inhibitor of miosis during phacoemulsification and provides a more stable mydriatic effect throughout the surgical procedure compared to topical ketorolac.