AIM: Diabetic patients suffer from severe dry eye after cataract surgery, and the aim of this study was to investigate the effect of 2.2 mm and 3.0 mm clear corneal incisions on dry eye after phacoemulsification in patients with type 2 diabetes mellitus (T2DM). METHODS: Clinical data of 104 patients with T2DM who underwent phacoemulsification in the Department of Ophthalmology of The People's Hospital of Yingshang from January 2022 to November 2023 were retrospectively collected. The patients were categorized into 2.2 mm and 3.0 mm groups according to the surgical incision, and their preoperative and postoperative Ocular surface disease index (OSDI), Schirmer I test (SIt), and Fluorescein breakup time (FBUT), as well as anxiety and depression levels, were analyzed. RESULTS: Before surgery, mild anxiety and depression were present in both groups. At 7 days and 1 month postoperatively, OSDI was significantly higher and SIt and FBUT were substantially lower in both groups, but the above indexes were milder in the 2.2 mm group. Meanwhile, the psychological status of both groups significantly improved at 1 month after surgery, and the improvement was more significant in the 2.2 mm group. At 3 months postoperatively, the dry eye of the two groups was relieved, and the psychological status was also improved. CONCLUSION: Compared with 3.0 mm, a 2.2 mm clear corneal incision effectively reduced dry eye after phacoemulsification in T2DM patients.