Purpose <p>We compared the efficacy of the Active Sentry and ozil handpiece, and evaluate the frequency of active surge mitigation (ASM) in the Active Sentry handpiece in cataract surgery according to nucleosclerosis grade.</p> Methods <p>600 eyes of 415 patients who underwent cataract surgery was retrospectively enrolled. Intraoperative parameters included phacoemulsification time (seconds), cumulative dissipated energy (CDE), and balanced salt solution (BSS) use (ml). Clinical measurements were made preoperatively and postoperatively, including the corneal endothelial cell (CEC) count in the Active Sentry (N = 300) and ozil handpiece group (N = 300). ASM activations were collected within the Active Sentry handpiece group. Nucleosclerosis was graded using the Lens Opacities Classification System III.</p> Results <p>ASM (times), phacoemulsification time, CDE, and BSS volume (ml) significantly increased with increasing nucleosclerosis grades and in patients with zonule weakness, poor mydriasis, and pseudoexfoliation syndrome in the Active Sentry handpiece group, respectively (<i>p</i> &lt; 0.05). Phacoemulsification time, CDE, and BSS volume of the Active Sentry handpiece group were significantly lower than the Ozil handpiece group (<i>p</i> &lt; 0.05). Phacoemulsification time, CDE, and CEC loss of Active Sentry group were significantly lower than the Ozil handpiece group in nucleosclerosis grade 5 and 6 (<i>p</i> &lt; 0.05). BSS volumes of the Active Sentry handpiece group were significantly lower than the Ozil handpiece group across all nucleosclerosis grade (<i>p</i> &lt; 0.05).</p> Conclusion <p>Because of the fast-reacting ASM, phacoemulsification time, CDE, and BSS volume were saved in the Active Sentry handpiece rather than in the Ozil handpiece. Therefore, ASM in the Active Sentry handpiece helps the surgeon perform safer cataract surgery in higher nucleosclerosis grade, zonule weakness, poor mydriasis, and pseudoexfoliation syndrome.</p>