A computer-implemented method for determining wave-front aberration data of a to-be-tested optical system comprising the steps of: a) providing a wave-front sensing image of light received from the tested optical system; b) providing a model representative of the optical system with at least an optical parameter representative of said model c) optimizing a set of wave-front coefficient data and said at least optical parameter of said model according to a merit function wherein the calculation of said merit function comprises the steps of: - generating a wave-front sensing modeled image of light received from said model by means of said at least optical parameter and said set of wave-front coefficient data; - calculating a criteria based on shape parameter data of the wave-front sensing image and shape parameter data of the wave-front sensing modeled image, so as to obtain wave-front aberration data of the tested optical system, wherein: - -said wave-front sensing image comprises an array of sensed focus light spots and; - said wave-front sensing modeled image comprises an array of modeled focus light spots, - the calculation of the criteria comprises the step of calculating a difference at least between a shape parameter of the sensed focus light spots and of the modeled focus light spots, - said model is an eye model comprising n reflective layers, n>1, and - generating the wave front sensing modeled image comprises: - obtaining a wave-front sensing image of light received from each illuminated reflective layer of said eye model and; - generating a wave-front sensing composite modeled image from the wave-front sensing images of the n reflective layers. a) providing a wave-front sensing image of light received from the tested optical system; b) providing a model representative of the optical system with at least an optical parameter representative of said model c) optimizing a set of wave-front coefficient data and said at least optical parameter of said model according to a merit function wherein the calculation of said merit function comprises the steps of: - generating a wave-front sensing modeled image of light received from said model by means of said at least optical parameter and said set of wave-front coefficient data; - calculating a criteria based on shape parameter data of the wave-front sensing image and shape parameter data of the wave-front sensing modeled image, so as to obtain wave-front aberration data of the tested optical system, wherein: - -said wave-front sensing image comprises an array of sensed focus light spots and; - said wave-front sensing modeled image comprises an array of modeled focus light spots, - the calculation of the criteria comprises the step of calculating a difference at least between a shape parameter of the sensed focus light spots and of the modeled focus light spots, - said model is an eye model comprising n reflective layers, n>1, and - generating the wave front sensing modeled image comprises: - obtaining a wave-front sensing image of light received from each illuminated reflective layer of said eye model and; - generating a wave-front sensing composite modeled image from the wave-front sensing images of the n reflective layers. - generating a wave-front sensing modeled image of light received from said model by means of said at least optical parameter and said set of wave-front coefficient data; - calculating a criteria based on shape parameter data of the wave-front sensing image and shape parameter data of the wave-front sensing modeled image, so as to obtain wave-front aberration data of the tested optical system, wherein: - -said wave-front sensing image comprises an array of sensed focus light spots and; - -said wave-front sensing image comprises an array of sensed focus light spots and; - said wave-front sensing modeled image comprises an array of modeled focus light spots, - the calculation of the criteria comprises the step of calculating a difference at least between a shape parameter of the sensed focus light spots and of the modeled focus light spots, - said model is an eye model comprising n reflective layers, n>1, and - generating the wave front sensing modeled image comprises: - obtaining a wave-front sensing image of light received from each illuminated reflective layer of said eye model and; - generating a wave-front sensing composite modeled image from the wave-front sensing images of the n reflective layers. - obtaining a wave-front sensing image of light received from each illuminated reflective layer of said eye model and; - generating a wave-front sensing composite modeled image from the wave-front sensing images of the n reflective layers.