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 OAT_ｚ-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 OAT_ｚgroup 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