A keratometer for intra-surgery measurements mounted under a surgical microscope includes a Placido ring illuminating a patient's eye； a video camera； a beamsplitter directing a Purkinje image of the Placido ring to the video camera； a fixation light directing a beam for patient eye fixation, fixation confirmation or creating a red reflex effect to enhance IOL imaging and cataract visualization； a processor configured to determine the refractive characteristics and keratometer parameters of the patient's eye and to execute a digital image enhancement method to outline IOL features to help IOL alignment； and a digital display displaying the keratometer parameters and surgical guidance information for a surgeon.
