Although the names sound similar, wavefront guided LASIK is different from wavefront optimized LASIK. The two versions of LASIK differ in how the optics of the eye are measured prior to surgery, measurements which are then used to program the excimer laser. With wavefront guided LASIK, a high resolution infrared laser beam is shined into the eye and the laser is measured as it passes back out of the eye to asses optics in three dimensions. This information is used to program the laser to customize the surgery to the individual eye being treated. With wavefront guided LASIK, the treatment is based on a refraction, the “which is better, one or two?” test. After the refraction is completed, this information is used to program the laser. The edges of the laser treatment are tapered using non-customized wavefront principles to improve overall optical quality. Edward Manche, MD, Director of the Byers Eye Institute’s Cornea and Refractive Surgery Center at Stanford University Medical School recently completed a head to head comparison study of wavefront guided LASIK versus wavefront optimized LASIK. Both eyes of 100 patients underwent surgery in the study. One eye had wavefront guided LASIK using the VISX S4IR laser and the other eye had wavefront optimized LASIK using the Alcon Allegretto Eye-Q laser. Both forms of LASIK yielded excellent outcomes. 97% of patients in both groups achieved 20/25 vision. Both groups showed very similar levels of accuracy.The wavefront guided group of eyes, however, showed better contrast resolution performance, which is considered one metric of visual quality. In the end, both platforms performed very well but there was an advantage to the VISX wavefront guided LASIK over the Alcon Allegretto Eye-Q laser.