Abstract:Calculating the intraocular lens(IOL)power in eyes with prior corneal refractive surgery(LASIK/PRK)is still a challenging task for all cataract ophthalmologists. The accuracy of the IOL power calculating is lower than virgin eyes, because the three generation formulae and traditional corneal instruments which measure central corneal radius of curvature in the paracentral 2.5-3.2mm zone are incorrect after myopic refractive surgery. There are three main sources of error in IOL calculation after refractive surgery: the radius measurement error, the keratometer index error and the IOL formula error. The purpose of the present paper is to describe the different available techniques to improve the accuracy of the IOL power calculation after refractive procedures.