A method, a system and a computer program for determining an eyeglass prescription for an eye are disclosed. Initially, information about a measurement indicative of the refractive properties of the eye is received. Subsequently, a mathematical representation of wavefront aberrations of the eye is determined from the measurement. The mathematical representation includes a multitude of polynomials, each polynomial having an azimuthal order and a radial order. Further, the mathematical representation includes at least a first polynomial group having a common radial order, wherein the common radial order is higher than two. The eyeglass prescription is determined based on a merit function, wherein each polynomial of the first polynomial group that is used in the merit function has an azimuthal order of −2, 0, or 2, respectively.