Abstract: The study explored the methods of determining the diameter of clear optic of intraocular lenses by analyzing the design principles and influencing factors of clear optic. Measure and compare the clear optic diameters of intraocular lenses from -10.0 D to 36.0 D respectively. The measurement results of the two methods have good consistency and can be used in the measurement of clear optic. But considering the accuracy and convenience of actual measurement, profile projector measurement principle is more suitable for conventional mass production testing. The Schlieren technique method can provide more useful information in product development and feature description stage, and can be used as an auxiliary verification method for clear optic diameter measurement.