Abstract： AIM:To evaluate the convenience and accuracy of a novel smartphone-assisted"any-point two-step method"for finding the target axial position in cataract phacoemulsification combined with intraocular lens(IOL)implantation.METHODS:Prospective observational study.A total of 62 cases(62 eyes)of patients with age-related cataracts who underwent cataract phacoemulsification combined with IOL implantation in our hospital from October 2021 to April 2022 were selected.They were randomly divided into two groups:31 cases(31 eyes)in the control group were applied with the"traditional two-step method"using slit lamp to mark the target axial position of the IOL,and 31 cases(31 eyes)in the experimental group were applied with the smartphone-assisted"two-step method"to mark the target axial position of the IOL.The Callisto eye navigation system was used as a standard reference,and the deviation of the reference marking point(deviation-1),the deviation of the target axial marking point(deviation-total),and the deviation of the angle from the reference marking point to the target axial marking point(deviation-2)were calculated and recorded as the preoperative axial marking time.RESULTS:Both deviation-1 and deviation-total values were lower in the experimental group than those in the control group(1.06°±1.39° vs 2.48°±2.23°,1.77°±1.54° vs 2.81 °±1.58°,all P＜0.01),but there was no significant difference in the deviation-2 values between the two groups(1.35°±1.40° vs 1.48°±1.79°,P＞0.05).The preoperative axial marking took shorter time in the experimental group than in the control group(1.77±1.70 min vs2.88±3.20 min,P＜0.01).CONCLUSION:The smartphone-assisted"any-point two-step method"for finding the target axial position in cataract phacoemulsification combined with IOL implantation is simple,time-saving,and accurate compared with the"traditional two-step method".