Abstract:AIM: To evaluate changes in visual acuity and accommodation function following femtosecond laser-assisted in situ keratomileusis (FS-LASIK) combined with monovision in patients aged over 40y. METHODS: This prospective, non-randomized cohort study included patients who were divided into an FS-LASIK binocular group (full correction) and an FS-LASIK monovision group. The binocular group consisted of Group 1 (15 patients) with simple myopia and Group 2 (12 patients) with myopia and presbyopia. The monovision group (Group 3) included 13 patients with myopia and presbyopia. Parameters assessed included the uncorrected distance visual acuity (UCVA), the uncorrected near visual acuity (UNVA), contrast sensitivity (CS), binocular cross-cylinder (BCC), accommodative amplitude (AMP), positive relative accommodation (PRA), negative relative accommodation (NRA), and accommodative facility (AF). Patient satisfaction was evaluated at 3mo postoperatively. RESULTS: A total of 40 patients (80 eyes) were enrolled (mean age 43.63±3.666y; 12 males). At 3mo after FS-LASIK, UCVA improved significantly in all patients (P<0.001), while UNVA remained comparable to preoperative levels (P>0.05). BCC in Group 3 decreased by 0.30±0.43 compared to preoperative levels, showing a statistically significant difference (P=0.037). The AMP in Group 3 showed an increasing trend with greater improvement in the nondominant eye than in the dominant eye (P>0.05). Patient satisfaction was high in all groups. CONCLUSION: FS-LASIK combined with monovision is an effective treatment for patients aged over 40y with myopia and presbyopia, which not only improves visual acuity but also achieves high patient satisfaction and improves postoperative BCC.