AIM: To investigate the effects of intraocular lens (IOL) implantation on visual field (VF) in patients with glaucoma and comorbid cataracts (G&C) with different disease severities. METHODS: Totally 56 eyes of 50 patients with primary G&C were included. All patients were divided into three groups based on the severity of the VF defect: the mild, moderate, and severe stage. Phacoemulsification was performed for cataract removal combined with IOL implantation. Visual acuity (VA) and VF tests were performed for all enrolled patients, up to 3mo after surgery. Changes in VF threshold and global VF index in various groups were also recorded before and after surgery. The mean light sensitivity (MS) values and the changes following surgery (DMS) were compared between the three groups. Advanced Glaucoma Intervention Study (AGIS) scoring was analyzed on all VF results for analysis of changes in VF before and after surgery. RESULTS: Following surgery, the MS values of the three groups of G&C increased significantly, while the AGIS scores decreased statistically in all groups. The DMS values for the three zones in moderate and severe stage but not mild stage were statistically different between zones. The DMS value was significantly higher in zone I than those in zone II and III (zone I>zone II>zone III; P<0.05). The DMS was significantly higher in zone I than that in zone III in moderate stage patients (zone I>zone II>zone III; P<0.01), while the DMS values in the severe stage patients was significantly higher in zone I than those in zone II and III (zone I>zone II>zone III; P<0.01). CONCLUSION: The mean VF sensitivity of glaucoma patients increased significantly after cataract removal and la implantation. Variations in the severity and distribution of characteristics of VF defects result in differences in postoperative VF improvements after cataract surgery. The magnitude of increase in VF sensitivity is associated with VF defect characteristic in glaucoma.