Abstract:To compare the visual effects of optimized aspheric transition zone Laser keratomileusis (OATz-LASIK ) versus conventional Laser in situ keratomileusis (con. LASIK). METHODS: In a prospective study 44 patients (88 eyes) underwent OATz-LASIK and 50 patients (92 eyes) received conventional LASIK surgery. Visual acuity,refractions、contrast sensitivity (CS), glare sensitivity (GS), and increment of Q-value after surgery were studied. RESULTS: All of operations on 94 cases were successful without severe complication after 3 months' follow-up. There was no significant difference in term of postoperative refractions between the two groups ( -test). The uncorrected visual acuity (UCVA), CS, GS, and increment of Q-value of OATzgroup were significantly better compared to the tradition group 3 months after the surgery ( <0.05). CONCLUSION: OATz- LASIK is a more effective procedure to improve visual quality compared to conventional LASIK