Method for designing a spectacle lens and spectacle lens

A method for designing and making a spectacle lens for a user, the spectacle lens including a first lens element and at least one second lens element, the first lens element having a front surface and a back surface that comprises a first back surface region and a second back surface region, the at least one second lens element comprising a front surface and a back surface, the second back surface region of the first lens element and the front surface of the second lens element being contiguous, a front surface of the spectacle lens being formed by the front surface of the first lens element and a back surface of the spectacle lens being formed in a base region by the first back surface region of the first lens element and in an achromatic region by the back surface of the at least one second lens element, the method comprising the steps of:

• first establishing a first material of the first lens element and a second material of the at least one second lens element;
• ascertaining at least one first transition point between the base region and the achromatic region on the back surface of the spectacle lens, a first cross-sectional plane of the spectacle lens extending through the at least one first transition point;
• first determining a wedge edge angle between the back surface of the at least one second lens element and the front surface of the at least one second lens element at the at least one first transition point in the first cross-sectional plane and determining a kink angle between a tangent of the first back surface region in the first cross-sectional plane at the at least one first transition point and a tangent of the back surface of the at least one second lens element in the first cross-sectional plane at the at least one first transition point, in such a way that a prismatic power of the spectacle lens in the base region at the at least one first transition point corresponds for the user to a prismatic power of the spectacle lens in the achromatic region at the at least one first transition point;
• second establishing a first radius of curvature of the back surface of the at least one second lens element in the first cross-sectional plane at the transition point;
• second determining a second radius of curvature of the front surface of the at least one second lens element of the at least one second back surface region of the first lens element in the first cross-sectional plane at the transition point, in such a way that a spherical power and an astigmatic power of the spectacle lens in the base region at the transition point correspond for a user of the spectacle lens to a spherical power and an astigmatic power of the spectacle lens in the achromatic region at the transition point;
• manufacturing the first lens element;
• manufacturing the at least one second lens element;
• and,
• connecting the first lens element and the at least one second lens element.

A computer program product having program code which is configured to carry out a method for designing a spectacle lens for a user when the computer program product is run on a data-processing device, the spectacle lens including a first lens element and at least one second lens element, the first lens element having a front surface and a back surface that comprises a first back surface region and a second back surface region, the at least one second lens element comprising a front surface and a back surface, the second back surface region of the first lens element and the front surface of the second lens element being contiguous, a front surface of the spectacle lens being formed by the front surface of the first lens element and a back surface of the spectacle lens being formed in a base region by the first back surface region of the first lens element and in an achromatic region by the back surface of the at least one second lens element, the computer program product comprising performing said method by carrying out the following steps:

• first establishing a first material of the first lens element and a second material of the at least one second lens element;
• ascertaining at least one first transition point between the base region and the achromatic region on the back surface of the spectacle lens, a first cross-sectional plane of the spectacle lens extending through the at least one first transition point;
• first determining a wedge edge angle between the back surface of the at least one second lens element and the front surface of the at least one second lens element at the at least one first transition point in the first cross-sectional plane and determining a kink angle between a tangent of the first back surface region in the first cross-sectional plane at the at least one first transition point and a tangent of the back surface of the at least one second lens element in the first cross-sectional plane at the at least one first transition point, in such a way that a prismatic power of the spectacle lens in the base region at the at least one first transition point corresponds for the user to a prismatic power of the spectacle lens in the achromatic region at the at least one first transition point;
• second establishing a first radius of curvature of the back surface of the at least one second lens element in the first cross-sectional plane at the transition point;
• and,
• second determining a second radius of curvature of the front surface of the at least one second lens element of the at least one second back surface region of the first lens element in the first cross-sectional plane at the transition point, in such a way that a spherical power and an astigmatic power of the spectacle lens in the base region at the transition point correspond for a user of the spectacle lens to a spherical power and an astigmatic power of the spectacle lens in the achromatic region at the transition point.

A spectacle lens comprising a first lens element and a second lens element, the first lens element being formed from a first material and the second lens element being formed from a second material, the first material and the second material interacting at least partially achromatically, the first lens element having a front surface and a back surface that comprises a first back surface region and a second back surface region, the at least one second lens element comprising a front surface and a back surface, the second back surface region of the first lens element and the front surface of the second lens element being contiguous, a front surface of the spectacle lens being formed only by the front surface of the first lens element and a back surface of the spectacle lens being formed in a base region by the first back surface region of the first lens element and in an achromatic region by the back surface of the at least one second lens element, the first back surface region of the first lens element having a first tangent at at least one first transition point between the base region and the achromatic region in a first cross-sectional plane of the spectacle lens, the back surface of the at least one second element having a second tangent at the at least one first transition point in the first cross-sectional plane, wherein the first tangent and the second tangent intersect one another at a kink angle in the first cross-sectional plane, the magnitude of the kink angle being less than 90°.

A spectacle lens comprising a first lens element and a second lens element, the first lens element being formed from a first material and the second lens element being formed from a second material, the first material and the second material interacting at least partially achromatically, the first lens element having a front surface and a back surface that comprises a first back surface region and a second back surface region, the at least one second lens element comprising a front surface and a back surface, the second back surface region of the first lens element and the front surface of the second lens element being contiguous, a front surface of the spectacle lens being formed by the front surface of the first lens element and a back surface of the spectacle lens being formed in a base region by the first back surface region of the first lens element and in an achromatic region by the back surface of the at least one second lens element, the first back surface region of the first lens element having a first tangent at at least one first transition point between the base region and the achromatic region in a first cross-sectional plane of the spectacle lens, the back surface of the at least one second element having a second tangent at the at least one first transition point in the first cross-sectional plane, wherein the first tangent and the second tangent intersect one another at a kink angle in the first cross-sectional plane, the magnitude of the kink angle being less than 90°;

• wherein the spectacle lens has two transition points in the first cross-sectional plane, the respective first tangent of the first back surface region and the respective second tangent of the back surface of the at least one second lens element intersecting one another at each of the two transition points.

A spectacle lens comprising a first lens element and a second lens element, the first lens element being formed from a first material and the second lens element being formed from a second material, the first material and the second material interacting at least partially achromatically, the first lens element having a front surface and a back surface that comprises a first back surface region and a second back surface region, the at least one second lens element comprising a front surface and a back surface, the second back surface region of the first lens element and the front surface of the second lens element being contiguous, a front surface of the spectacle lens being formed only by the front surface of the first lens element and a back surface of the spectacle lens being formed in a base region by the first back surface region of the first lens element and in an achromatic region by the back surface of the at least one second lens element, the first back surface region of the first lens element having a first tangent at at least one first transition point between the base region and the achromatic region in a first cross-sectional plane of the spectacle lens, the back surface of the at least one second element having a second tangent at the at least one first transition point in the first cross-sectional plane, wherein the first tangent and the second tangent intersect one another at a kink angle in the first cross-sectional plane, the magnitude of the kink angle being less than 90°;

• wherein the achromatic region extends in the first cross-sectional plane from the at least one first transition point to an edge of the spectacle lens.

A spectacles comprising:

• a frame;
• a first and a second spectacle lens;
• the first and/or the second spectacle lens being a spectacle lens including:
• a first lens element and a second lens element, the first lens element being formed from a first material and the second lens element being formed from a second material, the first material and the second material interacting at least partially achromatically, the first lens element having a front surface and a back surface that comprises a first back surface region and a second back surface region, the at least one second lens element comprising a front surface and a back surface, the second back surface region of the first lens element and the front surface of the second lens element being contiguous, a front surface of the spectacle lens being formed only by the front surface of the first lens element and a back surface of the spectacle lens being formed in a base region by the first back surface region of the first lens element and in an achromatic region by the back surface of the at least one second lens element, the first back surface region of the first lens element having a first tangent at at least one first transition point between the base region and the achromatic region in a first cross-sectional plane of the spectacle lens, the back surface of the at least one second element having a second tangent at the at least one first transition point in the first cross-sectional plane, wherein the first tangent and the second tangent intersect one another at a kink angle in the first cross-sectional plane, the magnitude of the kink angle being less than 90°;
• the cross-sectional plane or each cross-sectional plane of the respective spectacle lens containing a boxed centre of the respective spectacle lens and extending as a normal to a plane of the spectacle plane of the spectacles;
• and,
• the plane of the spectacle plane containing the vertical centerlines of the box of the first and second spectacle lenses.