CN-117321480-B - Spectacle lens and method for manufacturing spectacle lens

CN117321480BCN 117321480 BCN117321480 BCN 117321480BCN-117321480-B

Abstract

A spectacle lens having an inverse prism gradient of a sign different from that of an additional prism gradient on a progressive addition belt, the inverse prism gradient having an absolute value greater than 0.014 times the absolute value of the additional prism gradient on the progressive addition belt, at least in a distal region of the additional prism curve expressed as a function of the vertical direction coordinates of the spectacle lens, added with an internal prism which bends light in the direction of the wearer's nose.

Inventors

MATSUOKA SHOHEI

Assignees

豪雅镜片泰国有限公司

Dates

Publication Date: 20260505
Application Date: 20220324
Priority Date: 20210607

Claims (6)

1. An eyeglass lens having an inner prism for bending light in a direction toward a nose side of a wearer, At least in the distal region of the additional prism curve, expressed as a function of the coordinates in the vertical direction of the spectacle lens, the spectacle lens has an inverse prism gradient of a sign different from the additional prism gradient on the progressive zone, The absolute value of the inverse prism gradient is greater than 0.014 times the absolute value of the additional prism gradient on the progressive addition belt, on the principal meridian of the spectacle lens and on the umbilical point shifted to the wearer's nose by the internal prism.
2. The ophthalmic lens of claim 1, wherein the inverse prism gradient has an absolute value of less than 0.00625 delta/mm.
3. The spectacle lens according to claim 2, wherein the inverse prism gradient has an absolute value of less than 0.00625 Δ/mm both in the principal meridian of the spectacle lens and in the umbilical point shifted to the nose of the wearer by the internal prism.
4. A spectacle lens according to any one of claims 1 to 3, wherein the amount of added internal prisms varies according to viewing distance.
5. The spectacle lens according to any one of claims 1 to 3, wherein a difference between a maximum value and a minimum value of the amount of the added internal prism is 0.25 Δ or more.
6. A method of manufacturing an ophthalmic lens to which an internal prism for bending light toward a nose side of a wearer is added, the method comprising: A prism design step of designing the spectacle lens to have an inverse prism gradient of a sign different from that of the additional prism gradient on the progressive zone at least in a distal side region of the additional prism curve expressed as a function of coordinates in a vertical direction of the spectacle lens, In the prism design step, the absolute value of the inverse prism gradient is designed to be greater than 0.014 times the absolute value of the additional prism gradient on the progressive addition belt, on the principal meridian of the spectacle lens and on the umbilical point shifted to the wearer's nose by the inner prism.

Description

Spectacle lens and method for manufacturing spectacle lens Technical Field The present invention relates to an eyeglass lens and a method for manufacturing an eyeglass lens. Background It is known to add an internal prism in an amount corresponding to the diopter scale of the viewing distance, which bends the light toward the nose of the wearer, thereby supporting the reduction in convergence due to aging and reducing fatigue. Further, it is known that when an inner prism is added according to a viewing distance, astigmatism occurs due to distortion of a lens surface, and therefore, for example, in patent document 1, in order to reduce aberration, it is proposed to replace an additional prism curve with a smooth monotonically increasing curve. [ Prior Art literature ] [ Patent literature ] Patent document 1 Japanese patent application laid-open No. 2018-97283. Disclosure of Invention [ Problem to be solved by the invention ] Embodiments of the present invention aim to provide a technique that enables light to an inner prism that bends towards the nose of a wearer to reduce third order aberrations in the added additional spectacle lenses depending on viewing distance. [ Solution to the problem ] The first aspect of the invention is: an eyeglass lens having an inner prism for bending light in a direction toward a nose side of a wearer, At least in the distal region of the additional prism curve, expressed as a function of the coordinates in the vertical direction of the spectacle lens, the spectacle lens has an inverse prism gradient of a sign different from the additional prism gradient on the progressive zone, The absolute value of the inverse prism gradient is greater than 0.014 times the absolute value of the additional prism gradient on the progressive band. The second aspect of the invention is: The spectacle lens according to the first aspect, wherein the absolute value of the inverse prism gradient is greater than 0.014 times the absolute value of the additional prism gradient on the progressive addition belt, both on the principal meridian of the spectacle lens and on the umbilical point which is shifted to the nose of the wearer by the inner prism. A third aspect of the invention is: The ophthalmic lens of the first or second aspect, wherein the inverse prism gradient has an absolute value of less than 0.00625 delta/mm. A fourth aspect of the invention is: the spectacle lens according to the third aspect, wherein the absolute value of the inverse prism gradient is less than 0.00625 Δ/mm both on the principal meridian of the spectacle lens and on the umbilical point through the internal prism to the nasal side of the wearer. A fifth aspect of the invention is: The eyeglass lens according to any one of the first to fourth aspects, wherein an amount of the added inner prism varies according to the viewing distance. A sixth aspect of the invention is: the spectacle lens according to any one of the first to fifth aspects, wherein a difference between a maximum value and a minimum value of the amount of the added internal prism is 0.25 Δ or more. The seventh aspect of the present invention is: A method of manufacturing an ophthalmic lens to which an internal prism for bending light toward a nose side of a wearer is added, the method comprising: A prism design step of designing the spectacle lens to have an inverse prism gradient of a sign different from that of the additional prism gradient on the progressive zone at least in a distal side region of the additional prism curve expressed as a function of coordinates in a vertical direction of the spectacle lens, In the prism design step, the absolute value of the inverse prism gradient is designed to be greater than 0.014 times the absolute value of the additional prism gradient on the progressive band. [ Effect of the invention ] According to the embodiment of the present invention, the inner prism bending light toward the nose side of the wearer can reduce third order aberration in the added additional eyeglass lens according to the viewing distance. Drawings Fig. 1 (a) is an example of a power distribution diagram and an aberration distribution diagram without an internal prism, and fig. 1 (b) is an example of a power distribution diagram and an aberration distribution diagram with an internal prism. Fig. 2 (a) is a graph showing an example of an additional prism curve expressed as a function of coordinates in the vertical direction of the eyeglass lens, and fig. 2 (b) is a graph showing an example of a change in the sag Z around the principal meridian. Fig. 3 (a) is a graph showing an example of an additional prism curve, fig. 3 (b) is a graph showing an example of a gradient of the additional prism curve (first order differential of the additional prism curve), and fig. 3 (c) is a graph showing an example of a curvature of the additional prism curve (second order differential of the additional prism curve). Fig. 4 (a) is a diagram showing an example of