Spectacle lens, spectacle lens designing method, spectacle lens manufacturing method, and spectacle
A spectacle lens in which a region with a specific optical function has a high degree of freedom, and that has a better appearance and a better field of view compared to those achieved when lenses are joined at their cross sections. A spectacle lens and a technique associated therewith, the spectacle lens including a first lens and a second lens that are arranged overlapping each other in an optical axis direction, wherein the second lens has an opening, and the first lens covers the opening.
1. A spectacle lens comprising
a first lens and a second lens that are arranged overlapping each other in an optical axis direction, wherein:
the second lens has an opening,
the first lens covers the opening,
the spectacle lens is a multifocal spectacle lens, and
the multifocal spectacle lens includes a near portion corresponding to at least one near distance at the opening portion, and a distance portion corresponding to a distance farther than the near distance at a portion other than the opening and in which the second lens and the first lens overlap each other.
2. The spectacle lens according to claim 1 ,
wherein the distance portion corresponds to one distance farther than the near distance.
3. The spectacle lens according to claim 1 ,
wherein the thickness of the second lens decreases toward an edge of the opening.
4. The spectacle lens according to claim 1 ,
wherein a ratio of an area of the first lens in a front view relative to an area of the spectacle lens in a front view as viewed from a direction of the optical axis direction in which the first lens is disposed is 0.60 or more.
5. The spectacle lens according to claim 1 ,
wherein, when a direction of an object that a wearer is looking at in the optical axis direction is an object side, and a direction opposite thereto is an eyeball side,
the first lens is disposed on the object side, and the second lens is disposed on the eyeball side.
6. The spectacle lens according to claim 1 ,
wherein, when a direction of an object that a wearer is looking at in the optical axis direction is an object side, and a direction opposite thereto is an eyeball side,
an eyeball-side surface of the first lens and an object-side surface of the second lens are both a spherical surface or a toroidal surface, and
a curvature of the eyeball-side surface of the first lens and a curvature of the object-side surface of the second lens are equal.
7. The spectacle lens according to claim 1 ,
wherein the first lens and the second lens are joined to each other.
8. A spectacle in which the spectacle lens according to claim 1 is fitted into a frame in a state in which the spectacle lens is cut into a predetermined shape.
9. The spectacle lens according to claim 1 , wherein
when an optical axis direction is a Z-axis direction, and a Z-coordinate of an eyeball-side surface is a sag value, a ratio of an absolute value of an increase/decrease amount in mm of the sag value relative to a distance in mm in any direction perpendicular to the Z axis is 5.00 or less in the second lens.
10. The spectacle lens according to claim 1 , wherein
a thickness decrease ratio that is a thickness decrease amount in mm/a distance in mm in a direction extending toward an opening center or a gravity center, when a thickness decreases toward an edge of the opening is 1.00 or less in the second lens.
11. A spectacle lens manufacturing method comprising:
a lens obtaining step of obtaining, based on a prescription of a wearer, a first lens and a second lens that have been processed into predetermined shapes and that each have two main surfaces;
an opening forming step of forming, based on information relating to the wearer, an opening at a predetermined position of the second lens; and
after the lens obtaining step and after the opening forming step, a joining step of joining the first lens and the second lens to each other so as to be arranged in an optical axis direction, wherein:
the spectacle lens is a multifocal spectacle lens, and
the multifocal spectacle lens includes a near portion corresponding to at least one near distance at the opening portion, and a distance portion corresponding to a distance farther than the near distance at a portion other than the opening and in which the second lens and the first lens overlap each other.
12. The spectacle lens manufacturing method according to claim 9 ,
wherein the distance portion corresponds to one distance farther than the near distance.
13. The spectacle lens manufacturing method according to claim 11 ,
wherein, in the opening forming step, the thickness of the second lens is decreased toward an edge of the opening.
14. The spectacle lens manufacturing method according to claim 11 ,
wherein, in the joining step, a ratio of an area of the first lens in a front view relative to an area of the spectacle lens in a front view as viewed from a direction of the optical axis direction in which the first lens is disposed is set to 0.60 or more.
15. The spectacle lens manufacturing method according to claim 11 ,
wherein, when a direction of an object that a wearer is looking at in the optical axis direction is an object side, and a direction opposite thereto is an eyeball side,
in the joining step, the first lens is disposed on the object side, and the second lens is disposed on the eyeball side.
16. The spectacle lens manufacturing method according to claim 11 ,
wherein, when a direction of an object that a wearer is looking at in the optical axis direction is an object side, and a direction opposite thereto is an eyeball side,
an eyeball-side surface of the first lens and an object-side surface of the second lens are both processed into a spherical surface or a toroidal surface, and
a curvature of the eyeball-side surface of the first lens and a curvature of the object-side surface of the second lens are made equal.
17. The spectacle lens manufacturing method according to claim 11 ,
wherein, in the lens obtaining step, the first lens is obtained by processing an unformed surface of a semi-finished lens, and the second lens is obtained by processing both surfaces of a semi-finished lens.
18. A spectacle lens designing method comprising:
a lens designing step of designing a first lens and a second lens that have been processed into predetermined shapes and that each have two main surfaces so as to satisfy a prescription of a wearer when the first lens and the second lens are arranged overlapping each other in an optical axis direction; and
an opening setting step of setting, based on information relating to the wearer, an opening at a predetermined position of the second lens, wherein:
the spectacle lens is a multifocal spectacle lens, and
the multifocal spectacle lens includes a near portion corresponding to at least one near distance at the opening portion, and a distance portion corresponding to a distance farther than the near distance at a portion other than the opening and in which the second lens and the first lens overlap each other.
19. The spectacle lens designing method according to claim 18 ,
wherein the distance portion corresponds to one distance farther than the near distance.
20. The spectacle lens designing method according to claim 18 ,
wherein, in the opening setting step, the thickness of the second lens is decreased toward an edge of the opening.
21. The spectacle lens designing method according to claim 18 ,
wherein, when a direction of an object that a wearer is looking at in the optical axis direction is an object side, and a direction opposite thereto is an eyeball side,
an eyeball-side surface of the first lens and an object-side surface of the second lens are both designed in a spherical surface or a toroidal surface, and
a curvature of the eyeball-side surface of the first lens and a curvature of the object-side surface of the second lens are made equal.