A method for determining an optimal eyeglass lenses design for a viewer (1) comprising the successive steps of: showing the viewer (1) a stereoscopic scene including optical effects of a first lens design;—introducing a relative movement between the viewer (1) and the shown stereoscopic scene, said scene being shown with optical effects of the first lens design; expressing the viewer's opinion; showing the viewer (1) a stereoscopic scene including optical effects of a modified lens design; introducing a relative movement between the viewer (1) and the shown stereoscopic scene, said scene being shown with the modified lens optical effects; expressing again the viewer's opinion; repeating the three last steps up to viewer's satisfaction. A system for customizing vision correction suitable to implement said method. Related computer program for dynamically calculating a stereoscopic image. Related computer program for actuating an electro-active component.