The IOLmaster represents the best technology for measurements to be used in lens calculations to select the proper lens power for implantation during cataract surgery. To obtain highly precise measurement data, the IOLMaster uses Partial Coherence Interferometry (PCI) technology which is laser technology. In the past, axial measurements of the eye were obtained utilizing ultrasound technolgy which uses sound waves to make the measurements. Lasers offer a whole level of increased accuracy for taking the axial measurements of the eye which are critical in selecting the lens power of the implants used in cataract surgery. Ultrasound technology is still used if the cataract is too dense for laser measurement, but in those cases the technicians at Liva Eye center perform ultrasound using a special technique called immersion ultrasound which increases the accuracy over standard contact ultrasound.