Based on the eye model of Kooijman, the effects of the reflection losses and nonnormal incidence of laser on the human eye’s visual quality after refractive procedure on a cornea were analyzed by comparing the J. R. Jimenez’s theory and Munnerlyn’s. The reflection losses and nonormal incidence on the anterior cornea lead to the under-correction of the post-surgery eye. With the 6 mm diameter of the optical zone, when the refractive error of the eye before surgery is -9D, the under-correction is only -0.6D. The corneal asphericity after refractive surgery increases for myopia. With the increase of the refractive error before refractive surgery, the asphericity of the anterior cornea changes from negative to positive, which leads to the increase of the spherical aberration. There is no large difference between the asphericities obtained by Munnerlyn’s theory and Jimenez’s. The diameter of the optical zone has little effect on the post-surgery p-value.