Progressive addition eyeglass lens and method for manufacturing the same
AssigneesCartesian Optics B.V., Georgius Bruls
InventorsGeorgius Jozephus Cyrillus Ludovicus Bruls, Nikolas Martin Scholz
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Abstract
The present invention relates to a progressive addition lens and to a method for manufacturing the same. A lens comprises a rear surface intended to face an eye of the user and a front surface opposite to the rear surface. The present invention is particularly related to defining the rear surface of the lens. The present invention shows that it is possible to enhance image quality by using rotational symmetry in combination with a predefined progression curve to thereby avoid astigmatic imaging and also substantially reducing the effects of spherical aberration, coma, curvature of field and distortion.
Claims20
A method for manufacturing a progressive addition eyeglass lens, comprising:
- providing a predefined progression curve describing a desired optical power of the lens as a function of a viewing angle at which a user looks through the lens, wherein the lens comprises a rear surface intended to face an eye of the user and a front surface opposite to the rear surface;
- constructing front and rear vertex lines for the lens corresponding to the front and rear surfaces of the lens, respectively, by translating the progression curve into corresponding longitudinal curvatures for the front and back lens surface, wherein the vertex lines extend from a start point corresponding to a distance viewing area of the lens to an end point corresponding to a reading area of the lens;
- rotating the constructed rear vertex line around a first axis of rotation to construct a main rear surface;
- rotating the constructed front vertex line around a second axis of rotation to construct a main front surface, wherein the first and second axis of rotation are parallel to a line of sight, said line of sight corresponding to a line extending from an intended position of a user's eye relative to the eyeglass lens to a distant point when said user's eye is looking straight ahead;
- defining a cut-out region in the main rear surface and the main front surface thereby defining a lens to be manufactured;
- and
- manufacturing a lens in correspondence with the defined lens to be manufactured;
- wherein subjecting the defined lens to be manufactured to a differential torical deformation, and in that said manufacturing a lens in correspondence with the defined lens to be manufactured comprises manufacturing the lens to have a shape that corresponds to the deformed lens to be manufactured, wherein by using the differential torical deformation, optical power contour lines of the progressive addition eyeglass lens can be made to approximate horizontal lines, wherein subjecting the defined lens to be manufactured to a differential torical deformation causes the torical deformation to increase or decrease from a top of an initially rotationally symmetric progressive addition eyeglass lens to a bottom of said lens.
A progressive addition eyeglass lens having a rear surface intended to face the eye of a user and a front surface opposite to the rear surface;
- wherein the lens is manufactured in correspondence with a lens to be manufactured, said lens to be manufactured having been defined by defining a cut-out region in the main rear surface and the main front surface, wherein the main rear and front surface comprise a surface of revolution created by rotating a rear and front vertex line around a first and second axis of rotation, respectively, wherein the first and second axis of rotation are parallel to a line of sight, said line of sight corresponding to a line extending from an intended position of a user's eye relative to the eyeglass lens to a distant point when said user's eye is looking straight ahead, said rear and front vertex line corresponding to a translation of a progression curve into corresponding longitudinal curvatures for the rear and front lens surface;
- wherein the lens to be manufactured has been subjected to a differential torical deformation such that optical power contour lines of the progressive addition eyeglass lens approximate horizontal lines, wherein as a result of subjecting the defined lens to be manufactured to a differential torical deformation, the torical deformation increases or decreases from a top of an initially rotationally symmetric progressive addition eyeglass lens to a bottom of said lens.
Dependencies are inferred from the claim text.