Spectacle lens, spectacle lens design method, spectacle lens manufacturing method, and glasses

Abstract

To provide a spectacle lens which has a highly flexible region with a specific optical function, and offers good appearance and a good field of view compared with a spectacle lens fabricated by joining cross-sections of lenses together.SOLUTION: A spectacle lens consisting of a first lens and a second lens stacked in an optical axis direction and associated techniques are provided, where the second lens has an opening and the first lens covers the opening.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a spectacle lens, a method for designing a spectacle lens, a method for manufacturing a spectacle lens, and glasses. [Background technology]

[0002] Patent Document 1 discloses a bifocal lens in which a near-vision lens is placed on the object-side surface of a distance-vision lens, toward the lower nose side. The near-vision lens (the so-called near-vision portion, small lens) has a first lower side whose height (thickness) changes almost smoothly and is connected to the surface of the distance-vision lens, and a second side having a step with respect to the surface of the distance-vision lens.

[0003] Patent Document 2 discloses the following: A transparent adhesive is applied to the inner surface side of an optical glass lens having an outer surface curve, to provide a cushioning resin layer on the inner surface of the optical lens. A transparent synthetic resin plate is adhered onto this cushioning resin layer. This results in a see-through lens block made of a synthetic resin layer in which the transparent synthetic resin plate is bonded and integrated with a glass layer with the cushioning resin layer sandwiched therebetween. A glass-resin laminated lens for spectacles with a power (d) suitable for correcting the wearer's refractive malvision is produced by applying a curved surface polishing process to the synthetic resin layer of the lens block.

[0004] Non-Patent Document 1 discloses spectacles (Franklin lenses) in which, when the spectacle lenses are worn and viewed from the front, a distance lens is arranged above the spectacle lenses and a near lens is arranged below the spectacle lenses. Specifically, the document discloses bifocal spectacles in which a total of four lenses are made, each of which is a single-focus lens, a distance lens for the right eye, a distance lens for the left eye, and a near lens for the right eye and a near lens for the left eye, and each of these lenses is cut in half and fixed in a frame. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-191295 A [Patent Document 2] Patent No. 3884945 [Non-patent literature]

[0006] [Non-Patent Document 1] https: / / www.tokaiopt.info / corporate / technology / t08 / Summary of the Invention [Problem to be solved by the invention]

[0007] In both Patent Document 1 and Patent Document 2, a small bead needs to be formed in order to realize a near portion for viewing objects at a close distance. In both Patent Document 1 and Patent Document 2, the small bead protrudes from the object-side surface. In both Patent Document 1 and Patent Document 2, to form the small bead, it is necessary to cut out the parts other than the small bead, or to prepare a mold with the small bead formed in it and form the object-side surface.

[0008] In Non-Patent Document 1, a distance lens and a near lens are bonded together at their respective cross sections. Since the lenses are bonded together at their cross sections, there are bonded parts in the direction of travel of the light beam (the optical axis direction and the front-rear direction described below). This makes the bonded parts conspicuous and mars the appearance. As a result, objects cannot be seen well at the bonded parts, and the wearing comfort is reduced.

[0009] In both Patent Document 1 and Patent Document 2, a semi-finished lens, which is a semi-finished product, is usually prepared. In a semi-finished lens, for example, a small bead is formed in advance on the object side surface, the shape of the object side surface is in a finished state, and the eyeball side surface is in an unprocessed state (a flat plate (plato) or a concave surface having a predetermined curvature). Finally, the unprocessed eyeball side surface is processed to realize a shape that satisfies the prescription of the eyeglass lens wearer.

[0010] In both Patent Document 1 and Patent Document 2, it is necessary to prepare a semi-finished lens with a small lens in addition to a semi-finished lens for a general single focal length lens without a small lens. This leads to an increase in the inventory of semi-finished lenses.

[0011] In a semi-finished lens with small beads, the small beads are already formed, so it goes without saying that the position of the small beads on the semi-finished lens cannot be changed.

[0012] On the other hand, when the spectacle lens is fitted into a spectacle frame (hereinafter also simply referred to as a "frame"), the position in the frame through which the line of sight passes when the wearer looks at an object at a predetermined distance away changes according to the predetermined distance (whether infinity or a finite distance, or a specific value if the distance is finite). The predetermined distance is appropriately set according to the expected usage situation of the spectacle lens (e.g., whether it is for desk work or outdoor work). The position of the near portion (e.g., a conventional small lens) through which the line of sight passes when looking at an object closer than the predetermined distance changes according to the wearer's characteristics (e.g., the position of the line of sight in near vision) and the usage situation of the spectacle lens.

[0013] Depending on the shape of the frame in which the eyeglass lenses are fitted, it may be difficult to lay out the position of the small beads with existing semi-finished lenses. In response to this, it may be possible to prepare semi-finished lenses with large diameter small beads, thereby increasing the degree of freedom in the position of the small beads within the frame.

[0014] However, in that case, in addition to the already large inventory of semi-finished lenses with small lenses, a large-diameter semi-finished lens with a small lens would have to be prepared separately, leading to a further increase in inventory. Even if only large-diameter semi-finished lenses with small lenses were prepared, it would still be the same as preparing two types of semi-finished lenses, including a semi-finished lens for a general prime lens without a small lens, and an increase in inventory would be unavoidable.

[0015] As mentioned above, in both Patent Document 1 and Patent Document 2, to form the small ball, it is necessary to cut out the parts other than the small ball, or to prepare a die on which the small ball is formed, and then form the object side surface. Therefore, there is no freedom in the position of the small ball. Even if a semi-finished lens with a large diameter small ball is prepared, the freedom in the position of the small ball is low compared to when the position of the small ball can be freely set.

[0016] Not limited to the near vision area in a bifocal lens, when it is desired to form an area with a specific optical function inside the outer edge of a spectacle lens, it is meaningful to increase the degree of freedom regarding the position of the area.

[0017] In one embodiment of the present invention, an objective is to provide a spectacle lens that has a high degree of freedom in the area having a specific optical function, has a good appearance and provides a good field of vision compared to a case where lenses are bonded together at their cross sections. In particular, an objective is to realize a multifocal spectacle lens that has a high degree of freedom in the near area and is compatible with multiple distances without the need for conventional small lenses.

[0018] In one embodiment of the present invention, an object is to suppress an increase in the number of types of semi-finished lenses that accompanies the formation of small beads, and to increase the degree of freedom of a region having a specific optical function, particularly, to increase the degree of freedom of a near portion. [Means for solving the problem]

[0019] The first aspect of the present invention is A spectacle lens in which a first lens and a second lens are arranged side by side in an optical axis direction and overlap each other, the second lens has an aperture; The first lens is a spectacle lens that covers the opening.

[0020] A second aspect of the present invention is The spectacle lens is a multifocal spectacle lens, The multifocal eyeglass lens is the eyeglass lens described in the first aspect, which has a near portion corresponding to at least one near distance in the opening portion, and has a distance portion corresponding to a distance farther than the near distance in a portion other than the opening where the second lens and the first lens overlap.

[0021] A third aspect of the present invention is In the spectacle lens according to the second aspect, the distance portion corresponds to a distance farther than the near distance.

[0022] A fourth aspect of the present invention is In the spectacle lens according to any one of the first to third aspects, the second lens has a thickness that decreases toward the edge of the opening.

[0023] A fifth aspect of the present invention is The eyeglass lens according to any one of the first to fourth aspects, wherein a ratio of an area of ​​the first lens in a front view to an area of ​​the eyeglass lens in a front view from a direction in an optical axis direction in which the first lens is arranged is 0.60 or more.

[0024] A sixth aspect of the present invention is a method for producing a composition comprising the steps of: If the direction of the object that the wearer sees in the optical axis direction is the object side, and the opposite direction is the eyeball side, The spectacle lens according to any one of the first to fifth aspects, wherein the first lens is arranged on the object side, and the second lens is arranged on the eyeball side.

[0025] A seventh aspect of the present invention is If the direction of the object that the wearer sees in the optical axis direction is the object side, and the opposite direction is the eyeball side, an eyeball side surface of the first lens and an object side surface of the second lens are both spherical or toroidal surfaces, The spectacle lens according to any one of the first to sixth aspects, wherein the curvature of the eyeball side surface of the first lens is equal to the curvature of the object side surface of the second lens.

[0026] An eighth aspect of the present invention is a method for producing a composition comprising the steps of: The spectacle lens according to any one of the first to seventh aspects, wherein the first lens and the second lens are cemented together.

[0027] A ninth aspect of the present invention is a method for producing a composition comprising the steps of: a lens obtaining step of obtaining a first lens and a second lens, each having two main surfaces, which are processed into a predetermined shape based on a prescription of a wearer; an aperture forming step of forming an aperture at a predetermined position of the second lens based on information related to a wearer; a bonding step of bonding the first lens and the second lens in a line in an optical axis direction after the lens obtaining step and the opening forming step; The method for manufacturing a spectacle lens includes the steps of:

[0028] A tenth aspect of the present invention is a method for producing a composition comprising the steps of: The spectacle lens is a multifocal spectacle lens, A method for manufacturing a spectacle lens according to a ninth aspect, wherein the multifocal spectacle lens has a near portion corresponding to at least one near distance in the opening portion, and a distance portion corresponding to a distance farther than the near distance in a portion other than the opening where the second lens and the first lens overlap.

[0029] An eleventh aspect of the present invention is a method for producing a composition comprising the steps of: A tenth aspect of the present invention relates to a method for manufacturing a spectacle lens, and the distance portion corresponds to one distance that is farther than the near distance.

[0030] A twelfth aspect of the present invention is a method for producing a composition comprising the steps of: The method for manufacturing a spectacle lens according to any one of the 9th to 11th aspects, wherein in the opening forming step, a thickness of the second lens is reduced toward an edge of the opening.

[0031] A thirteenth aspect of the present invention is a method for producing a composition comprising the steps of: The method for manufacturing a spectacle lens according to any one of the 9th to 12th aspects, wherein in the bonding step, a ratio of an area of ​​the first lens in a front view from a direction in an optical axis direction in which the first lens is arranged to an area of ​​the spectacle lens in a front view is 0.60 or more.

[0032] A fourteenth aspect of the present invention is a method for producing a composition comprising the steps of: If the direction of the object that the wearer sees in the optical axis direction is the object side, and the opposite direction is the eyeball side, The method for manufacturing a spectacle lens according to any one of the 9th to 13th aspects, wherein in the bonding step, the first lens is disposed on the object side, and the second lens is disposed on the eyeball side.

[0033] A fifteenth aspect of the present invention is a method for producing a composition comprising the steps of: If the direction of the object that the wearer sees in the optical axis direction is the object side, and the opposite direction is the eyeball side, The eyeball side surface of the first lens and the object side surface of the second lens are both processed into a spherical or toroidal surface, The method for manufacturing a spectacle lens according to any one of the 9th to 14th aspects, wherein the curvature of the eyeball side surface of the first lens and the curvature of the object side surface of the second lens are made equal to each other.

[0034] A sixteenth aspect of the present invention is a method for producing a composition comprising the steps of: The method for manufacturing a spectacle lens according to any one of the 9th to 15th aspects, wherein in the lens obtaining step, an unformed surface of a semi-finished lens is processed to obtain the first lens, and both surfaces of the semi-finished lens are processed to obtain the second lens.

[0035] A seventeenth aspect of the present invention is a method for producing a composition comprising the steps of: a lens designing step of designing a first lens and a second lens, each having two main surfaces and processed into a predetermined shape, so that the first lens and the second lens satisfy the prescription of a wearer when the first lens and the second lens are overlapped side by side in an optical axis direction; an aperture setting step of setting an aperture at a predetermined position of the second lens based on information related to a wearer; The present invention relates to a method for designing a spectacle lens,

[0036] An eighteenth aspect of the present invention is a method for producing a composition comprising the steps of: The spectacle lens is a multifocal spectacle lens, A method for designing a spectacle lens according to a seventeenth aspect, wherein the multifocal spectacle lens has a near portion corresponding to at least one near distance in the opening portion, and has a distance portion corresponding to a distance farther than the near distance in a portion other than the opening where the second lens and the first lens overlap.

[0037] A nineteenth aspect of the present invention is a method for producing a composition comprising the steps of: The method for designing a spectacle lens according to an eighteenth aspect, wherein the distance portion corresponds to one distance farther than the near distance.

[0038] A twentieth aspect of the present invention provides a method for producing a composition comprising the steps of: The method for designing a spectacle lens according to any one of the seventeenth to nineteenth aspects, wherein in the opening setting step, a thickness of the second lens is reduced toward an edge of the opening.

[0039] A twenty-first aspect of the present invention is a method for producing a composition comprising the steps of: If the direction of the object that the wearer sees in the optical axis direction is the object side, and the opposite direction is the eyeball side, The eyeball side surface of the first lens and the object side surface of the second lens are both designed to be spherical or toroidal, The method for designing a spectacle lens according to any one of the seventeenth to twentieth aspects, wherein the curvature of the eyeball side surface of the first lens and the curvature of the object side surface of the second lens are made equal to each other.

[0040] A twenty-second aspect of the present invention is a method for producing a composition comprising the steps of: A pair of spectacles in which the spectacle lens according to any one of the first to eighth aspects is cut into a predetermined shape and fitted into a frame.

[0041] Other aspects of the present invention that can be combined with the above aspects are as follows.

[0042] The shape of the opening when viewed from the front is not limited, and may be a perfect circle or an ellipse (collectively, a circle). In the case of an ellipse, the horizontal direction when worn may be the long axis, and the vertical direction when worn may be the short axis, or vice versa. The opening may be disposed within the area of ​​the first lens, or the circle may be in contact with the outer edge of the first lens, or may be disposed in a shape in which a part of the circle is cut off by the outer edge of the first lens. The opening may be in a shape surrounded by a convex curve. For example, the outer periphery of the opening may have an arc with a radius of curvature (or an approximate radius of curvature) of 5 mm or more.

[0043] The size of the opening may be, for example, an opening with an inscribed circle diameter (diameter in the case of a perfect circle) of about 5 to 25 mm when viewed from the front. If the size is within this range, it will be larger than the diameter of a human pupil when mydriasis is present, and the second lens will function effectively.

[0044] The first lens may be a so-called plus lens, and in that case the second lens may be a minus lens.

[0045] It is preferable that the thickness of the second lens decreases toward the edge of the opening. If a step exists, the height of the step in the optical axis direction is 0.50 mm or less (preferably 0.30 mm or less, and more preferably 0.10 mm or less). More preferably, the thickness of the second lens gradually decreases toward the opening, and the position where the thickness becomes zero corresponds to the edge of the opening. In this case, at the edge of the opening, the eyeball side surface of the second lens and the eyeball side surface of the first lens are smoothly connected.

[0046] When the optical axis direction is the Z-axis direction and the Z coordinate of the surface on the eyeball side is the sag value (the lens center is the origin), it is preferable to suppress the ratio (ratio 1) of the absolute value of the increase or decrease in the sag value (unit: mm) to the distance (unit: mm) in any direction perpendicular to the Z-axis to a maximum of 5.00 or less (preferably 3.00 or less, more preferably 1.00 or less). For example, when the horizontal direction during wearing is the X-direction and the up-down direction is the Y-direction, the arbitrary direction perpendicular to the Z-axis is the X-direction or the Y-direction. It is preferable to keep the ratio 1 within the above range in both the X-direction and the Y-direction.

[0047] The above-mentioned provisions regarding the step may be applied not only to the locations corresponding to the openings, but also to the entire object-side surface and the entire eyeball-side surface of the multifocal spectacle lens.

[0048] It is preferable that the thickness reduction ratio (amount of thickness reduction (unit: mm) / distance (unit: mm) in the direction toward the center of the opening (or the center of gravity if it is difficult to determine the center)) (ratio 2) when the thickness decreases toward the edge of the opening is 1.00 or less (preferably 0.50 or less, and more preferably 0.30 or less).

[0049] The area of ​​the front view of the multifocal eyeglass lens from the direction of the optical axis in which the first lens is located (unit: cm 2 ) relative to the area of ​​the first lens in front view (unit: cm 2 ) (ratio 3) is preferably 0.60 or more (preferably 0.70 or more, more preferably 0.80 or more, even more preferably 0.90 or more, and particularly preferably 1.00). When it is less than 1.00, the outer edge of the first lens may cross within the area of ​​the spectacle lens.

[0050] It is preferable that the lens substrates of the first lens and the second lens are made of the same type of material.

[0051] The base curve of the object-side surface of the first lens that provides the near power may be determined by the distance power (spherical power S). Effect of the Invention

[0052] In one embodiment of the present invention, it is possible to provide a spectacle lens that has a high degree of freedom in the area having a specific optical function, and has a good appearance and a good field of vision compared to a case in which lenses are bonded together at their cross sections. In particular, it is possible to realize a multifocal spectacle lens that has a high degree of freedom in the near vision area and is compatible with multiple distances without the need for a conventional small lens.

[0053] In one embodiment of the present invention, it is possible to suppress an increase in the number of types of semi-finished lenses that accompanies the formation of small beads, and to increase the degree of freedom of a region having a specific optical function, particularly, the degree of freedom of a near portion. [Brief description of the drawings]

[0054] [Figure 1] FIG. 1 is a schematic diagram of a bifocal lens in Example 1, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, (d) is a perspective view, and (e) is a cross-sectional view taken along line AA in the figure. [Diagram 2] FIG. 2 is a schematic diagram of a bifocal lens in Example 2, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, (d) is a perspective view, and (e) is a cross-sectional view taken along line AA in the figure. [Diagram 3] FIG. 3 is a schematic diagram of a bifocal lens in Example 3, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, (d) is a perspective view, and (e) is a cross-sectional view taken along line AA in the figure. [Figure 4] FIG. 4 is a schematic diagram of a first lens in Example 3, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, and (d) is a perspective view. [Diagram 5] FIG. 5 is a schematic diagram of a second lens in Example 3, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, and (d) is a perspective view. [Figure 6] FIG. 6 is a schematic diagram of a bifocal lens in Example 4, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, (d) is a perspective view, and (e) is a cross-sectional view taken along line AA in the figure. [Figure 7] FIG. 7 is a schematic diagram of a bifocal lens in Example 5, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, (d) is a perspective view, and (e) is a cross-sectional view taken along line AA in the figure. [Figure 8] FIG. 8 is a schematic diagram of a bifocal lens in Example 6, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, (d) is a perspective view, and (e) is a cross-sectional view taken along line AA in the figure. [Figure 9] FIG. 9 is a schematic diagram of a first lens in Example 6, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, and (d) is a perspective view. [Figure 10] FIG. 10 is a schematic diagram of a second lens in Example 6, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, and (d) is a perspective view. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0055] Hereinafter, one embodiment of the present invention will be described. In this specification, the symbol "to" indicates a value greater than or equal to a given value and less than or equal to a given value.

[0056] <Eyeglass lenses> The spectacle lenses mentioned in this specification have an object-side surface and an eyeball-side surface. The "object-side surface" refers to the surface that is located on the object side when a wearer wears spectacles equipped with the spectacle lenses, and the "eyeball-side surface" refers to the opposite surface, that is, the surface that is located on the eyeball side when a wearer wears spectacles equipped with the spectacle lenses. This relationship also applies to the lens substrate that is the basis of the spectacle lenses. In other words, the lens substrate also has an object-side surface and an eyeball-side surface.

[0057] One embodiment of the present invention is a multifocal eyeglass lens. In this specification, "multifocal" includes not only two-focal (so-called bifocal) lenses, but also three-focal (so-called trifocal) lenses. The number of focal points is not limited as long as it is two or more. As an example, a bifocal lens will be given below. A method for realizing a trifocal lens will be described later.

[0058] A bifocal lens comprises a distance portion having a power set for an object at a predetermined distance from the wearer, and a near portion having a power set for an object at a near distance closer than the predetermined distance.

[0059] The distance portion is not particularly limited as long as it is an area for viewing a distance farther than a near distance. For example, it may be an area for viewing infinity or a predetermined distance (about 1 m). Examples of spectacle lenses with such an area include intermediate-near lenses that correspond to object distances of intermediate distances (1 m to 40 cm) to near distances (40 cm to 10 cm) and near-near lenses that correspond within the near distances.

[0060] In a multifocal eyeglass lens according to an embodiment of the present invention, a first lens and a second lens are arranged side by side in the optical axis direction and overlap each other. In this specification, the "optical axis direction" corresponds to the direction of the normal at the center of the object side surface and the eyeball side surface of the multifocal eyeglass lens. The optical axis direction is also the thickness direction of the eyeglass lens, and is the front-back direction as seen by a passing wearer. In other words, in one embodiment of the present invention, the arrangement of the first lens and the arrangement of the second lens are in a front-back relationship with each other.

[0061] The "center" described in the above paragraph is also referred to as the "lens center." The "lens center" refers to the geometric center, optical center, or centering center of a spectacle lens. In this specification, the centering center is exemplified. In this specification, the case where the center passes through the lens center when the wearer looks straight ahead is exemplified.

[0062] Just as a normal eyeglass lens has two main surfaces, the first lens has two main surfaces (e.g., Figs. 4 and 9 below), and the lens center can be defined. The second lens also has two main surfaces (e.g., Figs. 5 and 10 below), and the lens center can be defined.

[0063] The second lens has an aperture extending through the two major surfaces. 。

[0064] The first lens covers the opening. In this specification, "covering the opening" refers to a state in which the opening is completely covered by the first lens when viewed relative to the opening, that is, when the multifocal eyeglass lens is viewed from the front from the direction in which the first lens is arranged along the optical axis. "Covering the opening" can also be rephrased as a state in which a lid is placed on the opening.

[0065] For example, in Fig. 3 shown later, reference numeral 1 denotes a first lens, reference numeral 2 denotes a second lens, and reference numeral 3 denotes an aperture. In the bifocal lens indicated by reference numeral 10, the first lens 1 covers the aperture 3 of the second lens 2. Hereinafter, for the sake of convenience, the reference numerals will be omitted.

[0066] In this specification, the term "front view" refers to the state when the eyeglass lenses or eyeglasses are viewed from the front to the rear in the optical axis direction. The term "overlapping portion of the first lens and the second lens" refers to the portion where both lenses overlap when viewed from the front.

[0067] The shape of the opening seen from the front is not limited, and may be a perfect circle, an ellipse (collectively called a circle), or an approximately semicircular shape (lower side arc-shaped, upper side horizontal line-shaped) like the small beads of conventional bifocal lenses. In the case of an ellipse, the horizontal direction when worn may be the long axis, and the vertical direction when worn may be the short axis, or vice versa. The opening may be disposed within the area of ​​the first lens, or the circle may be in contact with the outer edge of the first lens, or a part of the circle may be cut off by the outer edge of the first lens. The opening may be a shape surrounded by a convex curve. For example, the outer periphery of the opening may have an arc with a radius of curvature (or an approximate radius of curvature) of 5 mm or more.

[0068] The size of the opening is not limited, but may be, for example, a diameter of the inscribed circle of about 5 to 25 mm in a front view. In this range, the diameter is equal to or larger than the diameter of a human pupil when dilated, and the second lens functions effectively.

[0069] There is no limitation on the manner in which the first lens and the second lens overlap. For example, the two lenses may be bonded together after an optical film such as a polarizing film or a photochromic film is interposed between the two lenses. In this case, the optical film may be interposed including the aperture, or it may not be interposed. Even if the optical film is interposed including the aperture, it is preferable to form a hard coat film on both sides of the multifocal eyeglass lens in this state.

[0070] Alternatively, the positional relationship between the two lenses may be fixed by attaching adhesive tape or the like to the side surfaces of the two lenses while leaving a small gap between them. This gap is preferably 1.0 mm or less in the front-to-rear direction (preferably 0.5 mm or less, more preferably 0.3 mm or less, and particularly preferably 0.1 mm or less). Of course, the two lenses may be directly bonded together without any gap. In other words, it is preferable that the first lens and the second lens are aligned in the optical axis direction and have at least partially overlapping surfaces. This example will be explained below. The bonding in this paragraph and the previous paragraph is also called "bonding".

[0071] There is no limitation on the manner of bonding, and both lenses may be bonded together using an adhesive or the like. In this case, both lenses may be bonded together entirely, or only the peripheries of both lenses may be bonded together. Both lenses may be bonded together by applying a photocurable resin between the two lenses, or both lenses may be bonded together using a thermosetting resin or a thermoplastic resin.

[0072] There is no limitation as to which of the first lens and the second lens is on the front side. However, if the second lens having an opening is arranged at the rear and the first lens is arranged at the front so as to cover the opening, no step is generated in the front part corresponding to the opening on the object side surface, which has a large influence on the appearance. In other words, it is preferable that the eyeball side surface of the first lens and the object side surface of the second lens are at least partially bonded or adhered to each other to form one eyeglass lens. Therefore, in this specification, the above example of this paragraph will be mainly described.

[0073] In a multifocal eyeglass lens according to one embodiment of the present invention, the aperture portion is a near portion corresponding to at least one near distance (one near distance in the case of a bifocal lens, and two near distances in the case of a trifocal lens).

[0074] That is, when the multifocal eyeglass lens is worn, the visual axis for an object at a near distance passes through the aperture. The near visual point, which is the intersection of the eyeball side surface of the multifocal eyeglass lens and the visual axis for an object at a near distance, is located within the aperture. The near visual point may be aligned with the center of the aperture (or the center of gravity if it is difficult to determine the center).

[0075] In the multifocal eyeglass lens, the portion where the first lens and the second lens overlap other than the aperture is a distance portion corresponding to a distance farther than a near distance.

[0076] The direction of refraction of the light beam passing through the aperture without coming into contact with the second lens is affected only by the surface shape of the first lens. In other words, the power of the near portion of the multifocal eyeglass lens (near power) is determined only by the first lens.

[0077] This means that by setting the position, size, shape in front view, etc. of the opening of the second lens (hereinafter also referred to as "position, etc."), a near vision portion with an arbitrary position, etc. can be formed. This is also called "high degree of freedom of the near vision portion." In addition, there is no need to join the lenses together at the cross section as in Non-Patent Document 1, and it is sufficient to overlap both lenses in the front-to-back direction.

[0078] As a result, in one embodiment of the present invention, a multifocal eyeglass lens can be provided that does not require the use of conventional small beads, has a good appearance, provides a good field of vision, and has a high degree of freedom in the near area, compared to lenses that are cemented together at their cross sections.

[0079] The distance portion of one embodiment of the present invention is constituted by the portion where the first lens and the second lens overlap. The power set in the distance portion is not limited as long as it can accommodate a distance longer than the near distance (i.e., the above-mentioned predetermined distance). In the case of a bifocal lens, this power corresponds to the distance power (spherical power) and is constant in the portion where the second lens and the first lens overlap. In this specification, the distance power refers to the power for visually recognizing an object at the above-mentioned predetermined distance (including infinity).

[0080] On the other hand, the power does not have to be one value throughout the distance portion. For example, the power may be set so that the power continues to decrease from the near power as it moves away from the near portion. In this case, the prescription (spherical power S) may be realized at the distance visual point. However, if the power is one value throughout the distance portion, distortion and blurring are reduced, which is preferable.

[0081] The method for realizing the distance portion is as follows: As described above, the first lens realizes the near power. The second lens may adopt a shape that reduces the near power provided by the first lens in the portion other than the aperture.

[0082] Specifically, the shape of the surface of the second lens (in this example, the outermost surface of the multifocal eyeglass lens on the eyeball side) facing the surface where the second lens and the first lens overlap (hereinafter, the cemented surface) may be a shape that reduces the power from the near power to a constant power when combined with the shape of the surface of the first lens facing the cemented surface (in this example, the outermost surface of the multifocal eyeglass lens on the object side). If this shape is reflected in the parts other than the opening, the power will be one value across the distance portion.

[0083] When the first lens is viewed alone, the refractive power (for convenience of explanation, hereinafter, the term "power") provided by the shapes of the two main surfaces is positive, and when the second lens is viewed alone, the power is negative. In other words, the first lens may be a so-called plus lens, and in that case, the second lens may be a minus lens.

[0084] In one embodiment of the present invention, the near portion is realized by the first lens alone, while the far portion is realized by overlapping the first lens and the second lens. In other words, in one embodiment of the present invention, the near portion is realized by the shapes of the two main surfaces of the first lens alone, while the far portion is realized by one main surface of the first lens (the object side surface of the first lens when cemented) and one main surface of the second lens (the eyeball side surface of the second lens when cemented).

[0085] For ease of explanation, the expressions "the object side surface of the first lens", "the eyeball side surface of the first lens", "the object side surface of the second lens", and "the eyeball side surface of the second lens" are used; however, these expressions are based on the assumption that the lenses are cemented together.

[0086] The near power is set by adding a certain power to the distance power. In this specification, this power is called the addition power. The addition power is a term usually used in progressive power lenses, but for the sake of convenience, the term addition power is used here.

[0087] In one embodiment of the present invention, the near power of the near portion realized by the first lens alone is reduced by an amount of addition power (in other words, a negative addition power is given) to set the distance power by combining the first lens with the second lens.

[0088] It is preferable that the thickness of the second lens decreases toward the edge of the opening. With this configuration, when the first lens is placed in front and the second lens is placed in the rear and the two lenses are cemented together, there is almost no step caused by the opening on the surface on the eyeball side. Even if a step exists, it is preferable that the height of the step in the optical axis direction is 0.50 mm or less (preferably 0.30 mm or less, and more preferably 0.10 mm or less). More preferably, the thickness of the second lens gradually decreases toward the opening, and the position where the thickness becomes zero corresponds to the edge of the opening. In this case, at the edge of the opening, the eyeball side surface of the second lens and the eyeball side surface of the first lens are smoothly connected.

[0089] Expressing the provision on the step in another way, when the optical axis direction is the Z axis direction and the Z coordinate of the surface on the eyeball side is the sag value (the origin is the lens center), it is preferable to suppress the ratio of the absolute value of the increase or decrease in the sag value (unit: mm) to the distance (unit: mm) in any direction perpendicular to the Z axis (hereinafter, ratio 1) to a maximum of 5.00 or less (preferably 3.00 or less, more preferably 1.00 or less). For example, when the horizontal direction during wearing is the X direction and the up-down direction is the Y direction, the arbitrary direction perpendicular to the Z axis is the X direction or the Y direction. It is preferable to keep the above ratio 1 within the above range in both the X direction and the Y direction.

[0090] The above-mentioned provisions regarding the step may be applied not only to the locations corresponding to the openings, but also to the entire object-side surface and the entire eyeball-side surface of the multifocal spectacle lens.

[0091] It is preferable that the thickness reduction ratio (amount of thickness reduction (unit: mm) / distance (unit: mm) in the direction toward the center of the opening (or the center of gravity if it is difficult to determine the center)) (hereinafter, ratio 2) when the thickness decreases toward the edge of the opening is 1.00 or less (preferably 0.50 or less, and more preferably 0.30 or less). The smaller the ratio 2, the sharper the edge becomes, forming a so-called knife-edge shape, and the less likely a step will occur.

[0092] The area of ​​the front view of the multifocal eyeglass lens from the direction of the optical axis in which the first lens is located (unit: cm 2 ) relative to the area of ​​the first lens in front view (unit: cm 2 ) (hereinafter, ratio 3) is small, the thickness of the multifocal eyeglass lens near the aperture can be set small. On the other hand, if ratio 3 is too small, the distance portion cannot be sufficiently secured. If importance is placed on securing the distance portion, it is preferable that the ratio is 0.60 or more (preferably 0.70 or more, more preferably 0.80 or more, even more preferably 0.90 or more, and particularly preferably 1.00). If it is less than 1.00, the outer edge of the first lens may cross within the area of ​​the eyeglass lens.

[0093] Furthermore, when the edge of the opening is knife-edge shaped, the boundary (bonding surface) with the first lens is not along the optical axis direction, but is rather shaped along the object side surface or eyeball side surface of the multifocal eyeglass lens. This allows the first lens and the second lens to be bonded smoothly, and the bonded boundary becomes less noticeable, compared to when the bonded part is along the optical axis direction as in Non-Patent Document 1. Even if the bonded boundary is visible, it is possible to make it invisible by forming a hard coat film.

[0094] In addition, the larger the ratio 3, the closer the boundary between the first lens and the second lens in the front view is to the periphery of the multifocal eyeglass lens. This contributes to a better appearance and a better field of view than when the boundary is closer to the center of the lens. From this point of view, the preferable range of the ratio 3 is significant.

[0095] The boundary (cemented surface) of the first lens and the second lens, i.e., the surface of the first lens facing the eyeball and the surface of the second lens facing the object in a multifocal eyeglass lens, are preferably both spherical or toroidal surfaces, and the curvatures of both surfaces are preferably equal. If the boundary of the cemented surface is a spherical or toroidal surface, it is easier to process and is advantageous in terms of manufacturing. The equal curvatures mean that the difference between the radii of curvature of both lenses is ±5% or less (preferably ±1% or less).

[0096] The shape of the object side surface (outermost surface) and the eyeball side surface (outermost surface) of the multifocal eyeglass lens, which face the cemented surface, may be spherical or toroidal, or may be aspherical (for example, rotationally symmetric aspherical).

[0097] There are no limitations on the material of the lens substrate of the first lens and the second lens. The types of materials may be different from each other. For example, the refractive indexes of both lens substrates may be different. However, if the types of materials are different, it will be necessary to increase the number of types of semi-finished lenses accordingly, so from the perspective of inventory of semi-finished lenses, it is best to use the same type of lens substrate for both lenses.

[0098] The technical scope of the present invention is not limited to the above-described embodiments, but includes forms in which various modifications and improvements are made within the scope in which specific effects can be obtained by the constituent elements of the invention and their combinations.

[0099] The present invention is not limited to the near vision portion of a bifocal lens, but can also be applied to a case where a region having a specific optical function is to be formed inside the outer edge of a spectacle lens. For example, a film having an optical function may be formed only on the opening.

[0100] A single-focus lens may also be obtained by bonding the first lens and the second lens. As described later in the section "Method of Manufacturing Spectacle Lenses," even if a semi-finished lens is not suitable for producing a single-focus lens having a specified diopter, the first lens and the second lens can be prepared by utilizing the semi-finished lens, and ultimately a single-focus lens that satisfies the prescription can be produced.

[0101] A trifocal lens may be obtained. In that case, it is preferable to prepare a third lens. The third lens overlaps (for example, cements) with the first lens and the second lens in the optical axis direction to form a multifocal eyeglass lens.

[0102] As an example, as described in the embodiment of the present invention, the first lens is located at the outermost surface on the object side, the second lens is located behind the first lens, and the third lens has another aperture that is concentric with the aperture of the second lens in the multifocal spectacle lens.

[0103] The other opening does not have to be completely the same shape as the opening of the second lens. For example, assume that the opening of the third lens is smaller than the opening of the second lens. In this case, in the multifocal eyeglass lens, the power of the part corresponding to the opening of the third lens, the power of the part between the opening of the third lens and the opening of the second lens, and the power of the part other than the opening of the second lens can be set. That is, in this case, the multifocal eyeglass lens becomes a trifocal lens. By applying this principle, four-focal and five-focal eyeglass lenses can also be realized.

[0104] <Glasses> The technical idea of ​​the present invention is also reflected in eyeglasses in which a first lens and a second lens are overlapped side by side in the optical axis direction, the second lens has an opening, and the first lens is a eyeglass lens that covers the opening, with the periphery cut based on a predetermined frame shape, and the eyeglasses are fitted into a frame. There are no limitations on the type, shape, etc. of the frame, and the frame may be full-rim, half-rim, under-rim, or rimless.

[0105] <Method of manufacturing eyeglass lenses> The present invention can also be applied to a manufacturing method of a spectacle lens. Specifically, the following aspects can be mentioned. In the following, the contents that overlap with the contents described in <Spectacle Lens> will be omitted as appropriate. "A lens obtaining step of obtaining a first lens and a second lens each having two main surfaces, the first lens and the second lens being processed into a predetermined shape based on a prescription of a wearer; an aperture forming step of forming an aperture at a predetermined position of the second lens based on information related to the wearer; a bonding step of bonding the first lens and the second lens in such a manner that they are aligned in the optical axis direction; A method for manufacturing a spectacle lens.

[0106] In the lens obtaining step, the first lens and the second lens are obtained. There is no limitation on the obtaining means. For example, the first lens and the second lens may be prepared in advance in a state in which no surface shape processing is required other than forming the aperture.

[0107] For example, a semi-finished lens may be prepared in advance, in which the distance power is provided when the object side surface of the first lens and the eyeball side surface of the second lens are combined, and the near power is provided by the two main surfaces of the first lens. The near power and the distance power can be freely set by combining the semi-finished lenses.

[0108] Specifically, the distance power can be freely set by combining the object side surface of the semi-finished lens used in the first lens with the eyeball side surface of the semi-finished lens used in the second lens. The near power can be freely set by the two main surfaces of the semi-finished lens used in the first lens.

[0109] The base curve of the object-side surface of the first lens that provides the near power may be determined by the distance power (spherical power S). To repeat, in one embodiment of the present invention, a negative addition power is given to the near power of the near portion realized by the first lens alone, and the distance power is set. Therefore, a semi-finished lens having a base curve that can correspond to the predetermined distance power and the predetermined addition power to be set as the object-side surface may be selected for the first lens.

[0110] The surfaces to be cemented (the eyeball side surface of the semi-finished lens used in the first lens and the object side surface of the semi-finished lens used in the second lens) should be processed so that their shapes match, and the shape is preferably spherical or toroidal.

[0111] If the shapes of both sides match, a certain level of bonding strength can be ensured when the two sides are overlapped without using adhesive. On the other hand, when considering the strength of multifocal eyeglass lenses, it is better to use adhesive. Also, even if the shapes of both sides do not match completely, it is possible to fill the gap between the two sides with adhesive. The use of adhesive makes it possible to tolerate differences in the shapes of the two sides.

[0112] On the other hand, according to the technical concept of the present invention, there is room to reduce the number of types of semi-finished lenses, as described below. In one embodiment of the present invention, this advantage may be utilized. This content will be described below along with an example of one embodiment of the present invention described in <Spectacle Lenses>.

[0113] The first lens is disposed in front of the second lens and covers the opening of the second lens. The overlapping portion of the first lens and the second lens in front view is the distance portion. The distance power in the distance portion is determined by the shape of the object side surface of the first lens and the shape of the eyeball side surface of the second lens. The near power in the near portion is determined by the portion of the first lens that overlaps with the opening of the second lens.

[0114] Therefore, a semi-finished lens in which the object side surface of the two main surfaces of the first lens is preformed may be used. Considering that the near vision power is exerted only by the first lens, it is possible to use a semi-finished lens (without a small lens) for an existing single vision lens. There is no need to unnecessarily increase the types of semi-finished lenses for the first lens according to one embodiment of the present invention.

[0115] The unformed surface of the semi-finished lens for the first lens, which faces the formed surface, is processed to be the bonding surface with the second lens. There is no limitation on the shape of the unformed surface, and it may be a flat plate (plato). However, in order to reduce the amount of processing, it is preferable to use a semi-finished lens having an unformed surface with a shape close to the shape of the planned bonding surface.

[0116] As described above in <Spectacle Lenses>, it is advantageous in terms of manufacturing to make the shape of the unformed surfaces after processing such that the eyeball side surface of the first lens and the object side surface of the second lens are both spherical or toroidal. In this case, it is preferable to make the curvature of the eyeball side surface of the first lens equal to the curvature of the object side surface of the second lens.

[0117] If the thickness of the second lens decreases toward the edge of the opening, the object side surface of the second lens is formed in accordance with the manner in which the thickness decreases. It is preferable to form the eyeball side surface of the first lens in accordance with the manner in which the thickness decreases.

[0118] The two main surfaces of the second lens may be processed together. The eyeball side surface of the second lens may be processed into a shape that exhibits distance power when overlapped with the object side surface of the first lens. If the thickness of the second lens decreases toward the edge of the opening, the object side surface of the second lens may be processed into a shape that matches the manner of the decrease.

[0119] In the manufacture of the second lens, a semi-finished lens having a shape close to the shape that exerts the distance power on one main surface may be used, or a flat plate with both main surfaces that are not processed may be used. In most cases, the second lens is processed to provide an opening. Therefore, even if a semi-finished lens is used, the shape of the two main surfaces of the semi-finished lens must be changed.

[0120] However, in other words, this means that there is a possibility that the second lens can be manufactured using a remaining semi-finished lens or a defective semi-finished lens whose formed surface deviates from the expected shape. In other words, it means that there is a possibility that the second lens can be manufactured using the same type of semi-finished lens as that used for the first lens.

[0121] Furthermore, to reiterate, the position of the opening etc. can be set arbitrarily in accordance with information related to the wearer, and openings in different positions etc. can be formed in one type of semi-finished lens.

[0122] The high degree of freedom in selecting the semi-finished lens for the second lens, and further the high degree of freedom in setting the position of the aperture, etc., as explained in <Spectacle lenses>, can lead to the elimination of inventory of semi-finished lenses.

[0123] As described in <Spectacle Lenses>, the surface of the first lens facing the eye may be processed so that the first lens has a positive power when viewed alone, or the first lens may be processed to be a plus lens. In that case, both surfaces of the second lens may be processed so that the second lens has a negative power when viewed alone, or the second lens may be processed to be a minus lens.

[0124] In one embodiment of the present invention, regarding the cylindrical power and cylindrical axis of the prescription, a semi-finished lens corresponding to the cylindrical power and cylindrical axis may be prepared in advance. However, in terms of reducing the types of semi-finished lenses, it is preferable to realize the cylindrical power and the cylindrical axis by processing the surface of the second lens on the eyeball side.

[0125] In the aperture forming step, an aperture is formed at a predetermined position of the second lens based on information related to the wearer. When the multifocal spectacle lens is worn, the visual axis for an object at a near distance passes through the aperture.

[0126] The information related to the wearer is a wearer parameter including a prescription. The contents of the prescription include a spherical power S, a cylindrical power C, a cylindrical axis Ax, and an add power ADD. For example, even if the add power ADD is the same between wearer α and wearer β, if the spherical power S and the cylindrical power C are different, the position of the opening in the multifocal spectacle lens for wearer α will differ from the position of the opening in the multifocal spectacle lens for wearer β. The size of the opening may be determined according to the wearer's request.

[0127] Examples of wearer parameters other than the prescription include the amount of inset when the wearer views near objects, the position of the near visual point, and the like.

[0128] The processing to make the edge of the opening into a knife edge shape may be performed during the opening forming step. During the opening forming step, the processing step for the object side surface of the second lens and the processing step for the eyeball side surface of the second lens may be performed together. In other words, for at least the second lens, the process of obtaining the second lens having two main surfaces each processed into a predetermined shape based on the prescription of the wearer and the process of forming the opening may be performed simultaneously. Apart from these processes, a processing step (i.e., a process of obtaining the first lens) may be performed on the eyeball side surface of the first lens so that the curvature is equal to that of the object side surface of the second lens.

[0129] In the bonding step, when the first lens is disposed on the object side and the second lens is disposed on the eyeball side, the surface of the first lens on the object side may be the already formed surface of the semi-finished lens as it is. On the other hand, in the opposite arrangement to that of the embodiment of the present invention, that is, when the second lens is disposed on the object side and the first lens is disposed on the eyeball side, the surface of the first lens on the eyeball side may be the already formed surface of the semi-finished lens as it is. In other words, in the lens obtaining step, only the unformed surface of the semi-finished lens may be processed to obtain the first lens, and both surfaces of the semi-finished lens may be processed to obtain the second lens.

[0130] In the bonding process, after the lens obtaining process and the opening forming process, the first lens and the second lens are bonded together in the optical axis direction. That is, the first lens and the second lens are placed in a desired relative position determined in advance so that they overlap at least partially, and then bonded together. At that time, as described in the previous paragraph, both lenses are bonded together so that the visual axis passes through the opening of the second lens during near vision. There is no limitation on the type of adhesive used in bonding, but if a material with a refractive index close to that of the material of the first lens and / or the second lens is used, the adhesive and the bonded surface of both lenses will not be noticeable.

[0131] The first lens and the second lens can be sufficiently processed by a known lens processing machine.

[0132] In one embodiment of the present invention, it is possible to suppress an increase in the number of types of semi-finished lenses that accompanies the formation of small beads, and to increase the degree of freedom of a region having a specific optical function, particularly, the degree of freedom of a near portion.

[0133] <Design method of eyeglass lenses> The present invention can also be applied to a method for designing eyeglass lenses. Specifically, the following aspects can be mentioned. Below, the contents that overlap with those described in <Eyeglass Lenses> and <Eyeglass Lens Manufacturing Method> will be omitted as appropriate. "A lens design process for designing a first lens and a second lens, each having two main surfaces processed into a predetermined shape, so that the first lens and the second lens satisfy the prescription of the wearer when overlapped side by side in the optical axis direction; an aperture setting step of setting an aperture at a predetermined position of the second lens based on information related to the wearer; A method for designing a spectacle lens comprising the steps of:

[0134] In the lens design process, the content of the lens acquisition process described in <Spectacle lens manufacturing method> can be adopted. In other words, the distance power in the distance portion can be determined by the shape of the object side surface of the two main surfaces of the first lens and the shape of the eyeball side surface of the two main surfaces of the second lens. At the same time, the near power in the near portion can be determined by the portion of the first lens that overlaps with the opening of the second lens.

[0135] In the aperture setting step, the contents of the aperture forming step described in <Method of manufacturing eyeglass lenses> can be adopted.

[0136] In one embodiment of the present invention, it is possible to suppress an increase in the number of types of semi-finished lenses that accompanies the formation of small beads, and to increase the degree of freedom of a region having a specific optical function, particularly, the degree of freedom of a near portion. EXAMPLES

[0137] The present invention will be described in detail below with reference to examples. The present invention is not limited to the following examples. This example shows that the near portion, i.e., the aperture, can be set at any position when the eyeglass lens is viewed from the front.

[0138] (Examples 1 to 3) The bifocal lenses according to Examples 1 to 3 were fabricated by placing the first lens in front and the second lens in the rear and cementing the two lenses together. The parameters of the bifocal lenses other than the position of the opening, which is the through hole in the second lens, are as follows: Base curve BC: 6.00D (diopter) Spherical power S:-1.00D Cylinder degree C: -2.00D Astigmatism axis Ax: 180 degrees Addition ADD:+1.00D Bifocal lens diameter: 70mm Front view shape of opening: perfect circle Aperture diameter: 24mm

[0139] The first lens was bonded to the object side of the second lens with an adhesive, leaving no gap between them. There was no difference in height between the object side and the eye side of the bifocal lens, and even if there was a difference in height, it was no more than 0.10 mm.

[0140] When the first lens was made, the applicant used a conventional semi-finished lens for a single-focus lens (BC 6.00 as described above). When the second lens was made, the applicant used a conventional semi-finished lens for a single-focus lens that had a shape close to the planned shape of the eyeball side surface of the bifocal lens. In other words, no new type of semi-finished lens was made for this example.

[0141] FIG. 1 is a schematic diagram of a bifocal lens in Example 1, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, (d) is a perspective view, and (e) is a cross-sectional view taken along line AA in the figure.

[0142] Hereinafter, in the schematic diagram of the bifocal lens, the first lens is made transparent and only the outline is shown, and the second lens is shown in gray. Note that the white dot in the upper center of the bifocal lens in the front view is a reflected image created by the function of the CAD software, and does not constitute the lens of the present invention.

[0143] Also, a section line AA is drawn on the first lens in the figure. This section line AA passes through the geometric center of the bifocal lens and the center of the aperture. Originally, since the geometric center of the bifocal lens and the center of the aperture coincide in Example 1, it is not necessary to draw the section line AA, but the section line AA is drawn to match Examples 2 and 3.

[0144] In Example 1, the center of the aperture was set so as to pass through the center of the second lens and to be located in the normal direction of the object-side surface of the second lens before the aperture was formed. In other words, the lens center of the bifocal lens and the center of the aperture were aligned.

[0145] FIG. 2 is a schematic diagram of a bifocal lens in Example 2, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, (d) is a perspective view, and (e) is a cross-sectional view taken along line AA in the figure.

[0146] In Example 2, the center of the opening was set to be located on a straight line that passed through the center of the second lens and was tilted 5 degrees downward and 5 degrees to the right (towards the nose of the wearer) from the normal direction of the object-side surface of the second lens.

[0147] FIG. 3 is a schematic diagram of a bifocal lens in Example 3, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, (d) is a perspective view, and (e) is a cross-sectional view taken along line AA in the figure. FIG. 4 is a schematic diagram of a first lens in Example 3, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, and (d) is a perspective view. FIG. 5 is a schematic diagram of a second lens in Example 3, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, and (d) is a perspective view.

[0148] In Example 3, the center of the opening was set to be located on a straight line that passed through the center of the second lens and was tilted 10 degrees downward and 10 degrees to the right (towards the nose of the wearer) from the normal direction of the object-side surface of the second lens.

[0149] (Examples 4 to 6) Bifocal lenses were produced according to Examples 4 to 6. The same parameters as those of Examples 1 to 3 were used, except that the addition power ADD of the bifocal lenses according to Examples 1 to 3 was changed from +1.00D to +3.50D.

[0150] In addition, in Examples 1 to 3, the ratio (ratio 3) of the area of ​​the first lens in a front view to the area of ​​the eyeglass lens in a front view from the direction in the optical axis direction in which the first lens is arranged was set to 1.00, but it was set to 0.60 or more and less than 1.00 in Examples 4 to 6. Incidentally, the eyeglass lens (particularly the first lens) may be intentionally made thicker to set ratio 3 to 1.00.

[0151] FIG. 6 is a schematic diagram of a bifocal lens in Example 4, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, (d) is a perspective view, and (e) is a cross-sectional view taken along line AA in the figure.

[0152] In Example 4, the center of the aperture was set so as to pass through the center of the second lens and to be located in the normal direction of the object-side surface of the second lens before the aperture was formed. In other words, the lens center of the bifocal lens and the center of the aperture were aligned.

[0153] FIG. 7 is a schematic diagram of a bifocal lens in Example 5, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, (d) is a perspective view, and (e) is a cross-sectional view taken along line AA in the figure.

[0154] In Example 5, the center of the opening was set to be located on a straight line that passed through the center of the second lens and was tilted 5 degrees downward and 5 degrees to the right (towards the nose of the wearer) from the normal direction of the object-side surface of the second lens.

[0155] FIG. 8 is a schematic diagram of a bifocal lens in Example 6, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, (d) is a perspective view, and (e) is a cross-sectional view taken along line AA in the figure. FIG. 9 is a schematic diagram of a first lens in Example 6, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, and (d) is a perspective view. FIG. 10 is a schematic diagram of a second lens in Example 6, where (a) is a front view, (b) is a side view as seen from the Y direction in the figure, (c) is a side view as seen from the X direction in the figure, and (d) is a perspective view.

[0156] In Example 6, the center of the opening was set to be located on a straight line that passed through the center of the second lens and was tilted 10 degrees downward and 10 degrees to the right (towards the nose of the wearer) from the normal direction of the object-side surface of the second lens.

[0157] As shown by Examples 1 to 6, it was possible to produce bifocal lenses that have a high degree of freedom in the near area, and that have a good appearance and provide a good field of view compared to lenses that are cemented together at their cross sections, even without the use of the conventional small beads. [Explanation of symbols]

[0158] 1...1st lens 2...Second lens 3…Aperture 10...Bifocal lens

Claims

1. A spectacle lens in which a first lens and a second lens are aligned and overlapped in an optical axis direction to satisfy a wearer's prescription, When the direction of an object viewed by the wearer in the optical axis direction is defined as the object side, and the opposite direction is defined as the eyeball side, The second lens disposed on the eyeball side has an opening, A spectacle lens, the first lens being disposed on the object side and covering the aperture.

2. The spectacle lens is a multifocal spectacle lens, The multifocal eyeglass lens according to claim 1, wherein the aperture portion has a near portion corresponding to at least one near distance, and the multifocal eyeglass lens has a distance portion corresponding to a distance farther than the near distance in a portion other than the aperture where the second lens and the first lens overlap.

3. The eyeglass lens according to claim 2 , wherein the distance portion corresponds to a distance farther than the near distance.

4. The eyeglass lens according to any one of claims 1 to 3, wherein the second lens has a thickness that decreases toward an edge of the opening.

5. The eyeglass lens according to any one of claims 1 to 4, wherein a ratio of an area of ​​the first lens in a front view to an area of ​​the eyeglass lens in a front view from a direction in which the first lens is arranged along an optical axis is 0.60 or more.

6. an eyeball side surface of the first lens and an object side surface of the second lens are both spherical or toroidal surfaces, 6. The eyeglass lens according to claim 1, wherein the curvature of the eyeball side surface of the first lens is equal to the curvature of the object side surface of the second lens.

7. The eyeglass lens according to any one of claims 1 to 6, wherein the first lens and the second lens are cemented together.

8. The second lens is a spectacle lens described in any one of claims 1 to 7, wherein, when the optical axis direction is the Z-axis direction and the Z coordinate of the surface on the eyeball side is the sag value, the ratio of the absolute value of the increase / decrease in sag value (unit: mm) to the distance (unit: mm) in any direction perpendicular to the Z axis is 5.00 or less.

9. The second lens is a eyeglass lens described in any one of claims 1 to 8, wherein the thickness reduction rate when the thickness decreases toward the edge of the opening (amount of thickness reduction (unit: mm)) / (distance toward the center of the opening or the center of gravity of the opening (unit: mm)) is 1.00 or less.

10. a lens obtaining step of obtaining a first lens and a second lens, each having two main surfaces, which are processed into a predetermined shape based on a prescription of a wearer; an aperture forming step of forming an aperture at a predetermined position of the second lens based on information related to a wearer; a bonding step of bonding the first lens and the second lens so as to be aligned in an optical axis direction after the lens obtaining step and the opening forming step; A method for manufacturing a spectacle lens comprising the steps of:

11. The spectacle lens is a multifocal spectacle lens, The method for manufacturing eyeglass lenses according to claim 10, wherein the multifocal eyeglass lens has a near portion corresponding to at least one near distance in the opening portion, and a distance portion corresponding to a distance farther than the near distance in a portion other than the opening where the second lens and the first lens overlap.

12. The method for manufacturing a spectacle lens according to claim 11 , wherein the distance portion corresponds to one distance farther than the near distance.

13. The method for manufacturing a spectacle lens according to any one of claims 10 to 12, wherein in the opening forming step, a thickness of the second lens is reduced toward an edge of the opening.

14. The method for manufacturing a eyeglass lens according to any one of claims 10 to 13, wherein in the bonding step, a ratio of an area of ​​the first lens in a front view to an area of ​​the eyeglass lens in a front view from a direction in which the first lens is arranged along an optical axis direction is 0.60 or more.

15. If the direction of the object that the wearer sees in the optical axis direction is the object side, and the opposite direction is the eyeball side, The method for manufacturing a spectacle lens according to any one of claims 10 to 14, wherein in the bonding step, the first lens is disposed on the object side, and the second lens is disposed on the eyeball side.

16. If the direction of the object that the wearer sees in the optical axis direction is the object side, and the opposite direction is the eyeball side, The eyeball side surface of the first lens and the object side surface of the second lens are both processed into a spherical surface or a toroidal surface, The method for manufacturing a spectacle lens according to any one of claims 10 to 15, wherein 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 to each other.

17. The method for manufacturing a spectacle lens according to any one of claims 10 to 16, wherein in the lens obtaining step, an unformed surface of a semi-finished lens is processed to obtain the first lens, and both surfaces of the semi-finished lens are processed to obtain the second lens.

18. a lens designing step of designing a first lens and a second lens, each having two main surfaces and processed into a predetermined shape, so that the first lens and the second lens satisfy the prescription of a wearer when the first lens and the second lens are overlapped side by side in an optical axis direction; an aperture setting step of setting an aperture at a predetermined position of the second lens based on information related to a wearer; A method for designing a spectacle lens comprising the steps of:

19. The spectacle lens is a multifocal spectacle lens, 20. The method for designing eyeglass lenses according to claim 18, wherein the multifocal eyeglass lens has a near portion corresponding to at least one near distance in the opening portion, and has a distance portion corresponding to a distance farther than the near distance in a portion other than the opening where the second lens and the first lens overlap.

20. The method for designing a spectacle lens according to claim 19 , wherein the distance portion corresponds to one distance farther than the near distance.

21. The method for designing a spectacle lens according to any one of claims 18 to 20, wherein in the aperture setting step, a thickness of the second lens is reduced toward an edge of the aperture.

22. If the direction of the object that the wearer sees in the optical axis direction is the object side, and the opposite direction is the eyeball side, The eyeball side surface of the first lens and the object side surface of the second lens are both designed to be spherical or toroidal, 22. The method for designing eyeglass lenses according to claim 18, wherein 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.

23. A pair of spectacles comprising the spectacle lens according to any one of claims 1 to 9, cut into a predetermined shape and fitted into a frame.

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