In one aspect, the invention features a method for determining an eyeglass prescription for an eye. The method includes obtaining a measurement of a wavefront indicative of the refractive properties of the eye, establishing an optimization space corresponding to a plurality of possible prescriptions for the eye, determining a value for a merit function for each of the possible prescriptions in the optimization space, where the merit function value corresponds to a visual function of the eye when corrected using the corresponding possible prescription, generating a representation of the merit function values, and outputting the representation to an eye care professional.