In recent years, ocular biometers based on swept-source optical coherence tomography(SS-OCT)technology have emerged in ophthalmic practice. Compared with the earlier ocular biometers such as the partially coherent interference(PCI)based ones, the SS-OCT based devices have a higher signal-to-noise ratio, greater swept light wavelength, better tissue penetration, faster scanning speed, and better axial length(AL)detection rate for cataract patients. This review aims to summarize the advances of a widely used SS-OCT based device-IOL Master 700 in cataract.