PURPOSE: To compare ocular higher order aberrations induced by corneal refractive therapy (CRT, Paragon Vision) to those produced by LASIK for patients with comparable levels of myopia. METHODS: A retrospective chart review of 11 patients who used CRT lenses and 12 patients who underwent LASIK for correction of low to moderate myopia was performed. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, and optical higher order aberrations were recorded before and 1 month after treatment for each patient. RESULTS: The CRT group consisted of 11 patients (4 men, 7 women) with a mean age of 29.1 +/- 5.2 years (range: 23 to 40 years), and the LASIK group consisted of 12 patients (3 men, 9 women) with a mean age of 39.2 +/- 12.0 years (range: 23 to 60 years). Manifest refraction decreased statistically significantly from -2.81 +/- 1.05 diopters (D) at baseline to -0.77 +/- 0.64 D following CRT treatment at 1 month (P<.0001) and from -3.11 +/- 1.21 D at baseline to -0.43 +/- 0.27 D at 1 month after LASIK (P<.0001). Both CRT and LASIK exhibited no significant changes in total higher order aberrations for 4-mm pupils but induced statistically significant increases in total higher order aberrations for 6-mm pupils. Corneal refractive therapy and LASIK both exhibited statistically similar factors of change for total higher order aberrations and coma-like higher order aberrations for 6-mm pupils. Corneal refractive therapy demonstrated a statistically significant greater factor of increase in spherical-like higher order aberrations for 6-mm pupils (P=.01). CONCLUSIONS: Contact lens corneal refractive therapy and LASIK can effectively correct myopia, but both increase higher order aberrations for 6-mm pupils to a similar degree. However, spherical-like aberrations were statistically significantly greater after CRT than after LASIK. [. 1 Refract Surg. 2010;26:348-355.] doi:10.3928/1081597X-20100218-03