Objective: To investigate the disparity between the set value of the capsulorhexis ring diameter in ophthalmic surgical navigation systems and the actual capsulorhexis ring diameter projected onto the lens surface. Methods: It was a cross-sectional study. Based on the Gullstrand eye model, the theoretical diameter of the capsulorhexis ring projected onto the lens plane through the cornea was calculated using the law of refraction in the Callisto Eye System. When the anterior chamber depth (ACD) ranged from 2.0 to 4.0 mm and the corneal curvature ranged from 40.00 to 48.00 D, the capsulorhexis ring diameters were calculated after projecting capsulorhexis rings with set diameters of 5.5 mm and 6.0 mm onto the lens plane. Additionally, 40 patients (40 eyes) aged 40 to 85 years who underwent cataract phacoemulsification combined with intraocular lens implantation at the Sixth People's Hospital of Shanghai Jiao Tong University School of Medicine were selected to validate the theoretical calculations. Among them, 15 were male, and 25 were female, and they were divided into three groups based on the ACD: group A (13 eyes) with ACD0.05), but the differences compared to the set values were statistically significant (all P<0.001). Conclusion: The capsulorhexis ring diameter projected onto the lens surface by the Callisto Eye system was reduced by 7.33% to 10.48% compared to the set value, and the degree of reduction increased with the increase of ACD and corneal curvature.