A method, a computer program, and an apparatus for determining a refractive value of a person's eye are disclosed along with a method for producing an ophthalmic lens for the person. A visual stimulus is displayed to the person, which includes a plurality of concentric radial lines, each radial line having a different angular value. A reaction by the person to the visual stimulus is recorded and the refractive value of the eye of the person is determined by evaluating the reaction of the person. Each radial line is projected at a particular defocus plane to the eye of the person, whereby a particular dioptric power is provided to the eye of the person. A recording of the reaction by the person to the visual stimulus indicates that a particular radial line at a particular angular value has an appearance of maximum sharpness to the eye of the person.