Methods and systems am disclosed in which an optical diagnosis of an eye's optical image quality is performed using a simulated retinal image. An objective measurement of a total wave aberration is obtained, and residual aberrations are computed by subtracting a sphero-cylindrical correction from the total wave aberration. The simulated retinal image is computed by computing a point-spread function from the residual aberrations and convolving the computed point-spread function with an acuity chart. The optical diagnosis includes at least one of: determining excess aberrations, ranking optics of the eye into optical grades, selecting the eye for high-definition eyeglasses, identifying amblyopia or macular diseases, or choosing an objective refraction for vision correction.