Progressive power lenses

Abstract

A progressive-addition lens is provided, comprising: a near portion having a refractive power for near observation; a distance portion having a refractive power for viewing objects farther away than near observation; and an intermediate portion having a progressive effect in which the refractive power gradually changes between the distance portion and the near portion. The progressive-addition lens is characterized in that it comprises a prismatic effect adjustment area, which makes the degree of image deformation caused by unnecessary prismatic effect caused by the progressive effect approach the degree of image deformation when wearing a reference single-focus lens corresponding to the progressive-addition lens or when wearing the lens with the naked eye.

Description

[0001] This application is a divisional application of the invention patent application with an international application date of June 28, 2019, application number 201980043196.3, and invention name “Design method, manufacturing method, design system and progressive refractive power lens”. Technical Field

[0002] The present invention relates to progressive-power lenses. It should be noted that the disclosure of Japanese Patent Application No. 2018-123739, which serves as the basis for the claim of priority, is incorporated herein by reference. Background Art

[0003] Among spectacle lenses, there are known spectacle lenses that have a portion whose diopter continuously changes. Such spectacle lenses are also called progressive-power lenses.

[0004] Examples include so-called progressive addition lenses having a distance portion and a near portion, and aspherical single-focal lenses whose power changes as the distance from a predetermined distance zone is exceeded.

[0005] For example, in progressive addition lenses, a curve called the principal fixation line is set as a reference line when the diopter changes continuously from the distance vision area to the near vision area.

[0006] The principal gaze line is the line formed by the portion of the lens through which the wearer's line of sight passes most frequently when the wearer wears the lenses and moves their gaze from the vertical direction (upward) to the ground (downward), or vice versa. This principal gaze line is the foundation for lens design. The shape of progressive-power lenses is designed so that the change in power from the distance to near vision zone along this principal gaze line corresponds to the power change specified in the prescription information.

[0007] Patent Document 1 discloses technology related to a progressive-power lens having an object-side surface (external, convex surface) and an eyeball-side surface (inner, concave surface). Specifically, the technology is described as controlling the refractive power at a distance reference point on the outer surface, where distance power is measured, and the refractive power at a near reference point on the outer surface, where near power is measured, to satisfy a predetermined relationship. This control reduces the difference in near and far magnification at a location unique to progressive-power lenses, thereby minimizing distortion perceived by the wearer.

[0008] Patent Document 2 discloses that an external prismatic effect occurs along the line of sight, which is considered to be the wearer's convergence. Furthermore, a progressive-power lens is provided with an internal prism shape that at least partially offsets this external prismatic effect along the line of sight, extending from the distance portion to the near portion. This internal prismatic effect can mitigate the increased convergence caused by the external prismatic effect along the line of sight.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: International Publication No. 03 / 100505 Pamphlet

[0012] Patent Document 2: International Publication No. 2016 / 104811 Pamphlet Summary of the Invention

[0013] Technical problem to be solved by the invention

[0014] The present inventors focused on the following technical problems unique to progressive-power lenses.

[0015] (Deformation in the depth direction)

[0016] Figure 1 This diagram schematically illustrates the position of a target object plane 20 as viewed from the sky (vertically upward) toward the ground (vertically downward) as seen by the wearer through conventional progressive-power lenses, namely, the right-eye lens 10R and the left-eye lens 10L, and the spectacle lens 10. Hereinafter, the target object plane 20 as seen is also referred to as the "viewing plane 20."

[0017] In the case of a conventional progressive-power lens, assume a state A in which a wearer visually sees an object at a position O that is a finite distance in front of the wearer and on the wearer's median plane.

[0018] Figure 2 This is a schematic explanatory diagram showing a state A in which the viewing surface 20 as viewed through a progressive-power lens is positioned closer to the front in the depth direction relative to the actual target object surface 22, when the wearer visually sees an object at a finite distance in front of the wearer at a location O on the wearer's median plane. Hereinafter, the actual target object surface 22 is also referred to as the "actual surface 22."

[0019] like Figure 2 As shown, the position of the surface 20 in the depth direction is seen to be located near the front side relative to the position of the actual surface 22 in the depth direction.

[0020] On the other hand, assume a state B in which an object at a portion P that is at the same vertical height as the portion O and located to the side of the portion O in the horizontal direction is visually observed in a plane parallel to the frontal plane and including the portion O. In state B, the position of the viewing surface 20 in the depth direction as seen through the eyeglass lens 10 is as follows: Figure 1 As shown, contrary to the previous example, the depth direction relative to the actual surface 22 is located on the depth side.

[0021] Specifically, with progressive-power lenses, the depth-direction position varies due to the difference in left and right eye convergence during binocular observation. Furthermore, the depth-direction position of the frontal portion O often differs from the depth-direction position of the lateral portion P. This can result in depth-direction image distortion. Eliminating this image distortion can provide a comfortable wearing experience.

[0022] (Difference in eye position in the up and down directions)

[0023] Figure 3 The diagram shows a vertical difference in eye position between the right eye R and the left eye L when observing a close and sideward object through the right eye lens 10R and the left eye lens 10L, which are conventional progressive-power lenses, when viewed horizontally.

[0024] like Figure 3 As shown, when a person wearing eyeglasses and gazing at a single point experiences a vertical difference in gaze direction between the two eyes, the wearer is forced to shift their eyes vertically to different left and right eye positions in order to achieve the same observation with both eyes. It should be noted that in this specification, gaze direction refers to the gaze direction of the eyeball, specifically the direction the right or left eye is facing.

[0025] The human eye generally has a low tolerance for differences in vertical prismatic effects, which can easily lead to discomfort even when the wearer can maintain consistent vision. Furthermore, if the degree of prismatic effect exceeds the wearer's tolerance, the image may be perceived as double vision. Eliminating vertical eye position differences can suppress this image perception, resulting in a more comfortable wear experience.

[0026] Therefore, an object of one embodiment of the present invention is to provide a technology that reduces the influence of unnecessary prismatic effect caused by progressive effect and achieves a comfortable wearing feeling.

[0027] Technical solutions to solve problems

[0028] As a method for solving the technical problems unique to progressive-power lenses, it is effective to make the state when wearing progressive-power lenses close to the state when wearing single-vision lenses or a state equivalent to the naked eye (described later).

[0029] On the other hand, according to this method, for example, a progressive refractive power lens is designed so that the state of an object located to the side at a limited distance (hereinafter referred to as "state B, progressive lateral observation state B") observed through a progressive refractive power lens is close to the state of observation through a single-vision lens or the state equivalent to that of the naked eye (hereinafter referred to as "state D, reference lateral observation state D").

[0030] However, in this case, if we only focus on the difference between the progressive lateral viewing state B and the reference lateral viewing state D, it becomes a state in which the elements caused by the unnecessary prismatic effect caused by the progressive action and the elements caused by the necessary prismatic effect caused by the added power for supporting the accommodation force in the progressive action, as listed in the column of the technical problem of the present invention, are mixed. The "elements caused by the necessary prismatic effect" can be listed, for example, as the amount of convergence required when viewing through a lens with an added power for supporting the accommodation force. The amount of convergence indicates the degree to which the left and right eyes deviate inward when viewing an object at a close distance. In this specification, the amount of convergence is also referred to as the amount of inward deviation. It should be noted that the "amount of inward deviation" in this specification sometimes indicates the degree of inward deviation of a single eye, and sometimes indicates the degree of inward deviation of both eyes.

[0031] If the elements caused by unnecessary prismatic effects due to gradual action and the elements caused by necessary prismatic effects are mixed, it is difficult to solve the technical problem of selecting and reducing the influence of unnecessary prismatic effects due to gradual action.

[0032] Therefore, the inventors focused on the difference V between the state when the wearer visually sees an object at a limited distance in front and at a position O on the wearer's median plane while wearing progressive refractive power lenses (state A described later, progressive front viewing state A) and the progressive side viewing state B just now.

[0033] One of the characteristics of this approach is that the convergence angle and eye position difference between the left and right eyes caused by the prism effect caused by the progressive effect of the progressive refractive power lens in the progressive frontal viewing state A are not eliminated, but accepted.

[0034] In the frontal viewing state at a limited distance, both the right and left eyes experience esotropia. Therefore, the depth-direction distortion and vertical eye position difference in the progressive frontal viewing state A already include the fundamental elements of esotropia. Furthermore, by focusing on the difference between the frontal and side viewing states, the fundamental elements of esotropia can be subtracted. In other words, both progressive addition lenses for the right and left eyes consider the left and right eye convergence angles and eye position differences when the line of sight passes through the principal fixation line. As a result, the difference between the difference V and the difference W primarily reflects the elements of unwanted prismatic effects caused by the progressive effect. This allows for the study of the elements of unwanted prismatic effects caused by the progressive effect.

[0035] Similarly, in the case of single-vision lenses or a state equivalent to that seen with the naked eye, attention was paid to the difference W between the reference front viewing state C and the reference side viewing state D. A method was devised to design a progressive-power lens so that this difference V approaches the difference W, thereby making the state when wearing the progressive-power lens closer to that when wearing a single-vision lens or a state equivalent to that seen with the naked eye.

[0036] Based on the above viewpoints, the following method is implemented.

[0037] A first aspect of the present invention is a method for designing a progressive-power lens, wherein the surface shape of the progressive-power lens is adjusted so that the difference V approaches the difference W.

[0038] The difference V is the difference between state A and state B when the progressive refractive power lens is worn, where state A is the state when the wearer visually sees an object at a limited distance in front of the wearer and at a position O on the wearer's median plane, and state B is the state when the wearer visually sees an object at a position P in a plane parallel to the front plane and containing the position O, at the same height in the vertical direction as the position O and located to the side of the position O in the horizontal direction.

[0039] The difference W is the difference between state C and state D when wearing a reference single-focus lens corresponding to a progressive refractive power lens or when viewed with the naked eye. State C is the state when visually viewing an object at position O, and state D is the state when visually viewing an object at position P.

[0040] A second aspect of the present invention is the aspect as described in the first aspect, wherein

[0041] The difference V is the difference between the angle difference VA between the right eye sight direction and the left eye sight direction in state A and the angle difference VB between the right eye sight direction and the left eye sight direction in state B.

[0042] The difference W is the difference between the angle difference WC between the right eye sight direction and the left eye sight direction in state C and the angle difference WD between the right eye sight direction and the left eye sight direction in state D.

[0043] By adjusting the surface shape of the progressive-power lens to vary the angle difference VB in state B, the difference V is restricted to a predetermined allowable range of the distance difference W.

[0044] A third aspect of the present invention is the aspect as described in the second aspect, wherein

[0045] Assuming that the center of rotation of the unified eye and the progressive power lens for the unified eye are set on the wearer's median plane and in the middle of the right eye and the left eye,

[0046] The angle difference VA is the difference between the angle difference VAR between the right eye sight direction and the unifying eye sight direction and the angle difference VAL between the left eye sight direction and the unifying eye sight direction in state A.

[0047] The angle difference VB is the difference between the angle difference VBR between the right eye sight direction and the unified eye sight direction and the angle difference VBL between the left eye sight direction and the unified eye sight direction in state B.

[0048] The angle difference WC is the difference between the angle difference WCR between the right eye sight direction and the unifying eye sight direction in state C and the angle difference WCL between the left eye sight direction and the unifying eye sight direction.

[0049] The angle difference WD is the difference between the angle difference WDR between the right eye sight line direction and the integrated eye sight line direction in state D and the angle difference WDL between the left eye sight line direction and the integrated eye sight line direction.

[0050] A fourth aspect of the present invention is the aspect as described in the third aspect, wherein

[0051] The correction amount of the progressive addition lens for the right eye and the correction amount of the progressive addition lens for the left eye when adjusting the surface shape of the progressive addition lens are proportionally allocated based on at least any one of the ratio of the angle difference VAR to the angle difference VAL, the ratio of the angle difference VBR to the angle difference VBL, the ratio of the angle difference WCR to the angle difference WCL, and the ratio of the angle difference WDR to the angle difference WDL.

[0052] A fifth aspect of the present invention is the aspect as described in the third or fourth aspect, wherein

[0053] The average of the spherical equivalent power of the progressive addition lens for the right eye and the spherical equivalent power of the progressive addition lens for the left eye is used as the spherical equivalent power of the progressive addition lens for the combined eye.

[0054] A sixth aspect of the present invention is the aspect as described in any one of the second to fifth aspects, wherein

[0055] The predetermined permissible range of the distance difference W is within 50% of the difference W.

[0056] A seventh aspect of the present invention is a method for manufacturing a progressive-power lens, comprising:

[0057] A design step of the method for designing a progressive-power lens according to any one of the first to sixth steps is performed, and a processing step of obtaining the progressive-power lens after the design step is performed.

[0058] An eighth aspect of the present invention is a system for designing a progressive-power lens, comprising a software module for adjusting the surface shape of the progressive-power lens so that the difference V approaches the difference W.

[0059] The difference V is the difference between state A and state B when the progressive refractive power lens is worn, where state A is the state when the wearer visually sees an object at a limited distance in front of the wearer and at a position O on the wearer's median plane, and state B is the state when the wearer visually sees an object at a position P in a plane parallel to the front plane and containing the position O, at the same height in the vertical direction as the position O and located to the side of the position O in the horizontal direction.

[0060] The difference W is the difference between state C and state D when wearing a reference single-focus lens corresponding to a progressive refractive power lens or when viewed with the naked eye. State C is the state when visually viewing an object at position O, and state D is the state when visually viewing an object at position P.

[0061] A ninth aspect of the present invention is a progressive-power lens comprising:

[0062] A near portion having a refractive power for near viewing; a distance portion having a refractive power for viewing an object farther than near viewing; and an intermediate portion having a progressive effect in which the refractive power gradually changes between the distance portion and the near portion;

[0063] The lens is provided with a prism action adjustment area which makes the degree of image deformation caused by the unnecessary prism action due to the progressive action close to the degree of image deformation when a reference single-focus lens corresponding to the progressive refractive power lens is worn or when the naked eye is worn.

[0064] A tenth aspect of the present invention is the aspect as described in the ninth aspect, wherein

[0065] The prismatic action adjustment region includes a region on the side that is deviated from the main viewing line in the horizontal direction.

[0066] An eleventh aspect of the present invention is the aspect as described in the ninth or tenth aspect, wherein

[0067] At least one of the following two conditions is met:

[0068] [Condition 1]

[0069] In a diagram plotted with the horizontal direction of the lens as the horizontal axis and the surface prism difference in the vertical direction normalized by the addition as the vertical axis, the difference between the maximum and minimum values of the surface prism difference in the vertical direction at a predetermined portion α on a predetermined horizontal cross-section in the near portion is 0.2 [prism diopters / diopters] or more;

[0070] [Condition 2]

[0071] In a drawing with the horizontal direction of the lens as the horizontal axis and the surface prism difference in the horizontal direction after normalization of the addition as the vertical axis, at the position x=0 within a specified portion γ on a specified horizontal cross-section in the near portion, the absolute value of the surface prism difference in the horizontal direction is greater than 0.25 [prism diopter / diopter], and the position x=0 within the specified portion γ is located directly below the prism reference point or directly below the midpoint of the two alignment reference marks of the progressive refractive power lens.

[0072] A twelfth aspect of the present invention is the aspect as described in the eleventh aspect, wherein

[0073] The position of the horizontal cross section is specified to be the position where the addition degree reaches 85% to 100%.

[0074] It is preferable to adjust the surface shape of the progressive-power lens so as to change only the angle difference VB in the state B, thereby limiting the difference V to a predetermined allowable range of the distance difference W.

[0075] Preferably, the spherical equivalent of a progressive addition lens is used as the spherical equivalent of a single-focus lens for reference.

[0076] Preferably, the area for adjusting the prism effect includes the area on the side that deviates from the main sight line in the horizontal direction. More preferably, the area including the area on the side that deviates from the main sight line in the horizontal direction and the area including the near part is used as the prism effect adjustment area.

[0077] The progressive-power lens may be replaced with a pair of progressive-power lenses consisting of a progressive-power lens for the right eye and a progressive-power lens for the left eye.

[0078] Preferably, [Condition 1] and [Condition 2] are satisfied.

[0079] It should be noted that it is also preferable to satisfy the following conditions.

[0080] [Condition 3]

[0081] The plot of the progressive-addition lens with the line of sight direction (tanθ) as the horizontal axis and the depth direction position information (unit: diopter) as the vertical axis does not intersect with the plot when wearing a reference single-focal lens corresponding to the progressive-addition lens or when wearing the naked eye.

[0082] Effects of the Invention

[0083] According to one embodiment of the present invention, it is possible to provide a technology for reducing the influence of unnecessary prismatic effect caused by progressive effect and achieving a comfortable wearing feeling. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] Figure 1 This is a schematic diagram showing the position of the target object surface as seen by the wearer through the right eye lens and left eye lens, which are existing progressive-power lenses, and the progressive-power lenses, when looking from the sky direction (vertically upward) toward the ground direction (vertically downward) of the sky.

[0085] Figure 2 This is a further schematic diagram showing a situation in which, when the wearer visually sees an object at a limited distance in front of the wearer and at a position O on the wearer's median plane, the position of the viewing surface in the depth direction as seen through an existing progressive refractive power lens is located near the front side relative to the depth direction of the actual target object surface in state A.

[0086] Figure 3 The diagram shows a vertical difference in eye position between the right eye and the left eye when observing a close and sideways object through the right eye lens and the left eye lens, which are conventional progressive-power lenses, when viewed from the horizontal direction.

[0087] Figure 4A 1 is a diagram showing the direction of sight lines of both eyes in a progressive frontal viewing state A when looking from vertically above to vertically below using a design method according to one embodiment of the present invention.

[0088] Figure 4B This diagram shows the direction of sight lines of both eyes in a progressive sideways viewing state B when viewing vertically downward from vertically above using the design method of one embodiment of the present invention.

[0089] Figure 4C This is a diagram showing the direction of sight lines of both eyes when looking vertically downward from vertically above, with reference to the front viewing state C, when the design method of one embodiment of the present invention is adopted.

[0090] Figure 4D This is a diagram showing the direction of sight lines of both eyes with reference to a side observation state D when looking vertically downward from vertically above when the design method of one embodiment of the present invention is adopted.

[0091] Figure 5 This is a diagram showing an example of a target object plane.

[0092] Figure 6This is a schematic diagram showing the position of the target object surface seen by the wearer through a progressive-power lens, i.e., a right-eye lens and a left-eye lens, and the progressive-power lens, when viewed vertically downward from vertically above, using a design method according to one embodiment of the present invention.

[0093] Figure 7 This diagram shows a situation in which there is no vertical difference in eye position between the right eye and the left eye when observing an object at a close distance and to the side through a progressive refractive power lens designed using one embodiment of the present invention when viewed from a horizontal direction.

[0094] Figure 8A This diagram shows the directions of the sight lines of the integrated eye and both eyes in a progressive frontal viewing state A when viewing vertically downward from vertically above using a design method according to one embodiment of the present invention.

[0095] Figure 8B This diagram shows the directions of the sight lines of the integrated eye and both eyes in a progressive lateral observation state B when viewing vertically downward from vertically above using a design method according to one embodiment of the present invention.

[0096] Figure 8C This is a diagram showing the directions of the sight lines of the integrated eye and both eyes when looking vertically downward from vertically above, with reference to the frontal viewing state C when the design method of one embodiment of the present invention is adopted.

[0097] Figure 8D This is a diagram showing the directions of the sight lines of the integrated eye and both eyes when looking vertically downward from vertically above, with reference to the side observation state D when the design method of one embodiment of the present invention is adopted.

[0098] Figure 9 The diagram shows a surface average power distribution diagram (left diagram) and a surface astigmatism distribution diagram (right diagram) illustrating a basic design of a progressive-power lens for combined eye use employed in a design method according to one embodiment of the present invention.

[0099] Figure 10 This is a schematic diagram showing the position of the target object surface as seen by the wearer of progressive-power lenses, namely, a right-eye lens, a left-eye lens, and a combined-eye lens, as well as progressive-power lenses, when viewed vertically downward from vertically above.

[0100] Figure 11 This is a diagram illustrating an example of a system for implementing a method for designing a progressive-power lens according to one embodiment of the present invention.

[0101] Figure 12This is a structural diagram showing the device configuration of a design device in a system for implementing a method for designing a progressive-power lens according to one embodiment of the present invention.

[0102] Figure 13 This is a diagram showing the flow of a method for designing a progressive-power lens according to one embodiment of the present invention.

[0103] Figure 14 This is a diagram showing an example of the surface astigmatism distribution of the right-eye lens and the left-eye lens initially designed while inwardly deviating from the surface astigmatism distribution of the integrated ophthalmic lens.

[0104] Figure 15 This is a diagram showing an example of changes in the surface average power distribution and surface astigmatism distribution on the lens surface before and after adjustment when the left-eye lens and the right-eye lens are progressive-power lenses.

[0105] Figure 16 1 and 2 are diagrams for explaining an example of a right-eye lens 300 in a pair of spectacle lenses according to each embodiment.

[0106] Figure 17 1 and 2 are diagrams for explaining a method of calculating a difference value distribution from the prism refractive power distributions on the lens surfaces of the right-eye lens 300 and the left-eye lens 400 .

[0107] Figure 18 (a) shows the distribution of the difference in the vertical direction of the line of sight between the two eyes when the reference lens is used when making a pair of eyeglass lenses, the lens of Example 1, and the existing lens is installed, that is, the eye position difference in the vertical direction, wherein the horizontal axis represents the horizontal component of the above line of sight direction, and the vertical axis represents the vertical component of the above line of sight direction. Figure 18 (b) is a graph showing changes in the viewing position in the depth direction of the target object plane 22, i.e., deformation in the depth direction. The vertical axis represents depth direction position information [diopter], and the horizontal axis represents the horizontal line of sight direction [tanθ].

[0108] Figure 19 (a) is a description Figure 18 The horizontal axis in (b) is a diagram showing the horizontal viewing direction. Figure 19 (b) is an explanation Figure 18 The vertical axis in (b) is a graph of position information in the depth direction.

[0109] Figure 20 This is a graph showing changes in horizontal surface prism differences in the lens of Example 1 and conventional lenses, where the vertical axis represents horizontal surface prism differences [prism diopter / diopter], and the horizontal axis represents the x-coordinate [mm] at y=-14mm.

[0110] Figure 21(a) shows the distribution of the difference in the vertical direction of the line of sight between the two eyes, that is, the difference in the eye position in the up-down direction, when the reference lens is used when making a pair of eyeglass lenses, the lens of Example 2, and the existing lens is installed. The horizontal axis shows the horizontal component of the line of sight direction, and the vertical axis shows the vertical component of the line of sight direction. Figure 21 (b) is a graph showing changes in the viewing position of the target object plane 22 in the depth direction, that is, deformation in the depth direction, where the vertical axis represents depth direction position information [diopter] and the horizontal axis represents the horizontal line of sight direction [tanθ].

[0111] Figure 22 This is a graph showing the changes in the surface prism difference in the vertical direction in the lens of Example 3 and the existing lens. The vertical axis represents the surface prism difference in the vertical direction [prism diopter / diopter], and the horizontal axis represents the x coordinate [mm] at y = -14 mm. DETAILED DESCRIPTION

[0112] Hereinafter, one embodiment of the present invention will be described. The following description is for illustrative purposes only, and the present invention is not limited to the exemplified embodiment.

[0113] In this specification, the vertical direction is referred to as the Y direction, the horizontal direction is referred to as the X direction, and the direction perpendicular to the two directions is referred to as the Z direction. The Z direction is the frontal viewing direction and is also perpendicular to the median plane and the frontal plane.

[0114] It should be noted that the direction of the line of sight in each state A, B, C, and D can be determined through simulation using ray tracing. Furthermore, the position along the lens where the line of sight passes can also be determined using ray tracing. Known ray tracing methods can be employed, and therefore detailed description will be omitted.

[0115] [Method for Designing Progressive-Power Lenses According to One Embodiment of the Present Invention]

[0116] The specific structure of the method for designing a progressive-power lens according to one embodiment of the present invention is as follows.

[0117] "A method for designing a progressive-power lens, wherein the surface shape of the progressive-power lens is adjusted so that the difference V approaches the difference W.

[0118] The difference V is the difference between a state A and a state B when the progressive refractive power lens is worn, wherein the state A is a state when the wearer visually sees an object at a portion O on the median plane of the wearer at a limited distance in front of the wearer, and the state B is a state when the wearer visually sees an object at a portion P on a plane parallel to the frontal plane and containing the portion O at the same vertical height as the portion O and located to the side of the portion O in the horizontal direction.

[0119] The difference W is the difference between a state C when wearing a reference single-focus lens corresponding to a progressive-power lens or when wearing the lens with the naked eye, and a state D when visually observing an object at the portion O and visually observing an object at the portion P.

[0120] A progressive-power lens has a distance portion, a near portion, and an intermediate portion as regions. The refractive power gradually changes from the distance portion to the near portion. The distance portion has a portion of the refractive power for observing distant objects arranged on the upper portion of the lens, that is, it has refractive power for distant observation. The near portion has a portion of the refractive power for observing near objects arranged on the lower portion of the lens, that is, it has refractive power for near observation. The intermediate portion is arranged between the distance portion and the near portion.

[0121] The distance portion is not particularly limited, as long as it is an area for observing distances farther than the near distance. For example, it can be an area for observing a predetermined distance (4m to 1m) rather than infinity. Examples of spectacle lenses with such an area include intermediate-near lenses corresponding to object distances from intermediate distances (1m to 40cm) to near distances (40cm to 10cm), and near-near lenses corresponding to distances within this range.

[0122] One embodiment of the present invention utilizes progressive-power lenses when worn. Specifically, binocular vision is achieved by wearing a pair of progressive-power lenses, consisting of a right-eye progressive-power lens and a left-eye progressive-power lens. A pair of progressive-power lenses is simply referred to as a lens pair or a spectacle lens pair. Furthermore, the right-eye progressive-power lens is also simply referred to as a right-eye lens, and the left-eye progressive-power lens is also simply referred to as a left-eye lens.

[0123] Figure 4A 1 is a diagram showing the direction of sight lines of both eyes in a progressive frontal viewing state A when looking from vertically above to vertically below using a design method according to one embodiment of the present invention.

[0124] State A refers to the state in which the wearer visually sees an object at a finite distance in front of them and located at a location O on the wearer's median plane. State A is also referred to as progressive frontal view state A. The median plane is the plane that divides the body of an animal that is bilaterally symmetrical and parallel to the middle of the body into two parts.

[0125] Figure 5 This is a diagram showing an example of a target object plane.

[0126] The specific value of the limited distance is not particularly limited. For example, it can be appropriately set within the range of 4m to 10cm. Figure 5Thus, a target object plane is appropriately set so that the distance from the wearer is long when above and short when below, and a part O and a part P described later are set on the target object plane. In this specification, as an example, a case where the distance from the part O to the wearer is 40 cm is described.

[0127] The target object plane preferably has a portion whose distance from the progressive-power lens 10 continuously decreases as it is located downward in the vertical direction.

[0128] Figure 4B This diagram shows the direction of sight lines of both eyes in a progressive sideways viewing state B when viewing vertically downward from vertically above using the design method of one embodiment of the present invention.

[0129] State B refers to the state in which an object is visually viewed at part P, which is at the same vertical height as part O and located horizontally to the side of part O, within a plane parallel to the cranial plane and containing part O. State B is also referred to as progressive lateral observation state B. The cranial plane is a plane perpendicular to the median plane, dividing the human body into ventral and dorsal sides, and is a plane parallel to the horizontal direction.

[0130] Then, the difference V between the front viewing state A and the side viewing state B when the progressive-power lens is worn is obtained.

[0131] The difference V and the difference W described later are not particularly limited as long as they are parameters that can express the difference in state, and an example thereof is the eye position difference.

[0132] Figure 4C This is a diagram showing the direction of sight lines of both eyes when looking vertically downward from vertically above, with reference to the front viewing state C, when the design method of one embodiment of the present invention is adopted.

[0133] Figure 4D This is a diagram showing the direction of sight lines of both eyes with reference to a side observation state D when looking vertically downward from vertically above when the design method of one embodiment of the present invention is adopted.

[0134] On the other hand, grasp the state C when visually seeing an object at position O (refer to the front observation state C) when wearing a reference single-focus lens corresponding to the progressive refractive power lens or when wearing the naked eye, and the state D when visually seeing an object at position P (refer to the side observation state D).

[0135] Regarding the reference single-focal lens, it is assumed that the reference single-focal lens for the right eye corresponds to the progressive-addition lens for the right eye, and the reference single-focal lens for the left eye corresponds to the progressive-addition lens for the left eye. The same applies to the reference single-focal lens hereinafter. In addition, the reference single-focal lens may be simply referred to as the reference lens.

[0136] The specific structure of the reference single-vision lens is not particularly limited, as long as it possesses the basic performance of a progressive-power lens, excluding the progressive component. Specifically, the lens has the same spherical power S, preferably an equivalent spherical power (S + C / 2) that takes into account the astigmatism C. The following example illustrates the case where the equivalent spherical power of a progressive-power lens is used in a reference single-vision lens.

[0137] Alternatively, the reference single-focus lens may be, for example, an aspheric lens for correcting astigmatism or an aspheric lens for reducing off-axis aberrations. However, since the reference single-focus lens serves as a reference object (target) for suppressing deformation of the image of the actual surface 22, it is preferred that the image deformation be minimal. Therefore, the reference single-focus lens is preferably a spherical lens. Furthermore, for the same reason, the reference single-focus lens preferably has a prism power Δ of zero. Δ is the unit of prism power, and refers to the offset of a 1cm ray of light in a direction perpendicular to the direction of travel of the ray of light when the ray of light travels for 1m.

[0138] Furthermore, the wearer's prescription data is recorded in the lens bag of the progressive-power lens. That is, if a lens bag is present, the wearer's prescription data can be used to identify the object as a progressive-power lens. Furthermore, progressive-power lenses typically come with a lens bag. Therefore, progressive-power lenses that come with a lens bag also reflect the technical concept of the present invention, and the same applies to the combination of a lens bag and progressive-power lenses.

[0139] The so-called "equivalent to the naked eye" includes the naked eye state, and also includes the case of wearing a lens with a spherical power of zero, so-called zero-power lens.

[0140] Then, the difference W between the front viewing state C and the side viewing state D when the reference single-vision lens is worn or when the naked eye is worn is obtained.

[0141] Then, the progressive-power lens is designed so that the difference V when the progressive-power lens is worn approaches the difference W when a reference single-vision lens is worn or when the lens is worn with the naked eye.

[0142] The specific design method is not particularly limited. For example, the prismatic effect can be adjusted by adjusting the curvature of the lens surface within an acceptable range while also adjusting the gradient of the lens surface, thereby bringing the difference V closer to the difference W. More specifically, multiple adjustment points can be set on the lens, and the prism effect at each adjustment point can be varied in the vertical and horizontal directions to bring the difference V closer to the difference W.

[0143] The area for adjusting the prism effect is preferably mainly an area on the progressive-power lens that does not include the main gaze line. For example, the area for adjusting the prism effect preferably includes an area laterally offset from the main gaze line in the horizontal direction.

[0144] It should be noted that the principal gaze line refers to the line formed by the portion of a spectacle lens through which the line of sight passes. Furthermore, in one embodiment of the present invention, for ease of explanation, the principal gaze line in a progressive-power lens is defined as the line connecting the distance power measurement point and the near power measurement point. Furthermore, this definition is also practically applicable when determining the position of the principal gaze line in actual lenses.

[0145] However, of course, in one embodiment of the present invention, the focus is on the difference V between the state (described later as state A, progressive frontal viewing state A) when the wearer visually sees an object at a finite distance in front of them and located on the wearer's median plane, and the progressive lateral viewing state B. This focus itself is not limited to the shape of the principal gaze line (either straight or curved). First, given that the shape of the principal gaze line varies depending on the wearer, the shape and position of the principal gaze line itself as a component of the spectacle lens of one embodiment of the present invention does not need to be uniquely defined.

[0146] When the lateral portion horizontally offset from the principal gaze line is used as the prismatic effect adjustment area, the prismatic effect can be adjusted without affecting the spherical power S, cylindrical power C at the distance reference point, and the addition power at the near reference point provided as prescription information for the progressive-power lens. Furthermore, it is also preferable to use the area including the near portion as the prismatic effect adjustment area. Furthermore, it is also preferable to use the area horizontally offset from the principal gaze line and including the near portion as the prismatic effect adjustment area.

[0147] Figure 6 This is a schematic diagram showing the position of the target object surface seen by the wearer through a progressive addition lens, i.e., a right-eye lens and a left-eye lens, and a progressive addition lens designed using one embodiment of the present invention, when viewed vertically downward from vertically above.

[0148] Figure 7 This figure shows a situation in which no vertical eye position difference occurs in the right eye R and the left eye L when observing an object at a close distance and to the side using a progressive refractive power lens designed using one embodiment of the present invention when viewed from a horizontal direction.

[0149] Regarding the technical issues (deformation in the depth direction), Figure 6As shown, in the progressive frontal viewing state A of an object at observation location O, a depth offset occurs between the actual surface and the perceived surface. However, as described in the technical solution section, one embodiment of the present invention does not consider the left and right eye convergence angles and eye position difference in the progressive frontal viewing state A. Therefore, this offset is itself a predicted offset. On the other hand, in the progressive side viewing state B, the depth offset in the progressive frontal viewing state A is maintained. In other words, the depth offset disappears or nearly disappears between frontal and side views.

[0150] Regarding the problem described in the technical question column (upper and lower eye level difference), Figure 7 As shown, when the design method of one embodiment of the present invention is adopted, the difference V is brought close to the difference W, so that the vertical eye position difference in the side view disappears or almost disappears.

[0151] As a result, one embodiment of the present invention can reduce the effects of unnecessary prismatic effects caused by the progressive effect, resulting in a comfortable fit. In particular, a comfortable fit can be achieved during intermediate vision (when looking through the intermediate portion of the progressive-power lens) and near vision (when looking through the near portion).

[0152] [Details of the method for designing a progressive-power lens according to one embodiment of the present invention]

[0153] Hereinafter, further specific examples, preferred examples, and modified examples of one embodiment of the present invention will be described.

[0154] The difference V is the difference between the angle difference VA between the right eye sight direction and the left eye sight direction in state A and the angle difference VB between the right eye sight direction and the left eye sight direction in state B.

[0155] The difference W is the difference between the angle difference WC between the right eye sight direction and the left eye sight direction in state C and the angle difference WD between the right eye sight direction and the left eye sight direction in state D.

[0156] The angle differences VA, VB, WC, and WD are essentially eye level differences that combine the horizontal and vertical vector components generated by the prism effect of the surface shape of the progressive-power lens. Alternatively, the vertical eye level difference can be set using only the vertical vector component of each of the angle differences VA, VB, VC, and VD. Conversely, the horizontal eye level difference can also be set using only the horizontal vector component.

[0157] From the perspective of the vertical eye level difference described in the technical problem, it is preferable that the vertical eye level difference be included in the eye level difference. In other words, it is preferable to set the eye level difference by combining the horizontal and vertical vector components, or to set the vertical eye level difference by using only the vertical vector component of each of the angle differences VA, VB, VC, and VD.

[0158] By using the eye position differences represented by the angle differences VA, VB, VC, and VD as the basis of the differences V and W, it is possible to directly grasp the solution of the technical problem (distortion in the depth direction) (eye position difference in the vertical direction), which is therefore preferred.

[0159] On top of this, the angle difference VB in the state B may be varied by adjusting the surface shape of the progressive-power lens, thereby limiting the difference V to within a predetermined allowable range of the distance difference W.

[0160] In addition, when the value of "difference" in this specification is negative, the absolute value is used as the value of the difference.

[0161] The predetermined allowable range may be, for example, within 50% of the difference W (0.5W≦V≦1.5W), more preferably within 40%, and even more preferably within 30%. The lower limit is not particularly limited, but may be, for example, 5% or 10%.

[0162] Assume that the eye position difference is used as the basis of the difference V and the difference W, and a comparison is made between the wearing of a progressive-power lens and the wearing of a reference single-vision lens or the naked eye.

[0163] It should be noted that the direction of sight can also be expressed, for example, by an inclination angle relative to the direction of frontal observation through the right-eye lens, the left-eye lens, the right-eye reference single-focus lens, the left-eye reference single-focus lens, and the integrated eye lens (described later), that is, the Z direction perpendicular to the median plane and the front plane.

[0164] As described in the technical proposal section, the progressive front view state A of the progressive addition lens when worn is acceptable in one embodiment of the present invention, even if (depthwise deformation) (vertical eye position difference) occurs. This means that the design of the progressive addition lens in state A does not need to be changed. Of course, design changes are not excluded within the scope of the present invention.

[0165] Furthermore, the reference front view state C and the reference side view state D, which refer to the state when the single-vision lens is worn or when the lens is viewed with the naked eye, are for reference only and do not require any design changes. Of course, design changes are not excluded within the scope of the present invention.

[0166] As a result, by changing only the angle difference VB in the progressive lateral viewing state B when the progressive-power lens is worn, the difference V can be limited to the prescribed allowable range of the distance difference W, significantly reducing work time. A specific benefit is that it facilitates design to meet the prescribed addition power ADD. Furthermore, the position of the portion O in the depth direction does not change due to adjustment of the lens surface shape. Therefore, it is easy to obtain an appropriate lens surface shape.

[0167] It is also preferable to use a cyclops eye and a progressive-power lens for the cyclops eye, which assumes that the rotation center is set on the median plane of the wearer and at a position between the right eye and the left eye.

[0168] Figure 8A This diagram shows the directions of the sight lines of the integrated eye and both eyes in a progressive frontal viewing state A when viewing vertically downward from vertically above using a design method according to one embodiment of the present invention.

[0169] Figure 8B This diagram shows the directions of the sight lines of the integrated eye and both eyes in a progressive lateral observation state B when viewing vertically downward from vertically above using a design method according to one embodiment of the present invention.

[0170] Figure 8C This is a diagram showing the directions of the sight lines of the integrated eye and both eyes when looking vertically downward from vertically above, with reference to the frontal viewing state C when the design method of one embodiment of the present invention is adopted.

[0171] Figure 8D This is a diagram showing the directions of the sight lines of the integrated eye and both eyes when looking vertically downward from vertically above, with reference to the side observation state D when the design method of one embodiment of the present invention is adopted.

[0172] Regarding the optical performance of the progressive addition lens for the combined eye, if the parameters (spherical power S, astigmatism C, equivalent spherical power (S+C / 2), prism power Δ, added power ADD, progressive zone length, internal deviation, etc.) are the same for the progressive addition lens for the right eye and the progressive addition lens for the left eye, the same values of the parameters may be used. In this case, it is also possible to design only one of the progressive addition lens for the right eye or the progressive addition lens for the left eye, and design the progressive addition lens for the other eye so that the distribution pattern of the designed progressive addition lens is bilaterally symmetrical.

[0173] For simplicity, the specific examples described in this specification adopt this situation, using the equivalent spherical power (S+C / 2). Furthermore, the average of the equivalent spherical powers of the right-eye lens and the left-eye lens is used as the parameter for the integrated ophthalmic lens. Furthermore, the astigmatism power C and the prismatic power Δ are set to zero. This is because, similar to the preference for setting the astigmatism power C and the prismatic power Δ to zero in the reference single-focus lens, even integrated ophthalmic lenses preferably have minimal image distortion.

[0174] It should be noted that if the parameters of the right-eye lens and the left-eye lens are different, the average value of the two parameters may be used. For example, the average value of the spherical equivalent power of the right-eye lens and the spherical equivalent power of the left-eye lens may be set as the spherical equivalent power of the integrated eye lens.

[0175] It should be noted that the method for determining the parameters of the integrated single-focal lens for the right eye and the reference single-focal lens for the left eye can be the same as the method for determining the parameters of the integrated lens in the progressive-power lens described above. For example, the average of the spherical equivalent power of the reference single-focal lens for the right eye and the spherical equivalent power of the reference single-focal lens for the left eye can be used.

[0176] Figure 9 The diagrams are a surface average power distribution diagram (left diagram) and a surface astigmatism distribution diagram (right diagram) showing a basic design of an integrated ophthalmic lens used in a design method according to one embodiment of the present invention.

[0177] Figure 9 The origin of each distribution graph shown represents the lens center 240, i.e., the prism measurement point. The vertical direction on the page represents the vertical direction of the lens surface, and the horizontal direction on the page represents the horizontal direction of the lens surface. The distribution graph is a 60 mm square. Contour lines for surface astigmatism and surface average power are drawn at 0.25 D (diopter) intervals. The content described in this paragraph also applies to the distribution graphs that appear later.

[0178] Figure 9 Shown are a distance reference point 220 and a near reference point 230. In addition, the positions of hidden markings 302, 304 in the eyeglass lens are also shown.

[0179] exist Figure 9 In the illustrated surface average power distribution, the power at the distance reference point 220 is set to the spherical power S included in the prescription information. The power at the near reference point 230 is set to the power obtained by adding the addition power ADD described in the prescription information to the spherical power S at the distance reference point 230.

[0180] In this specification, the surface average power distribution is a distribution of values obtained by multiplying the average value of the maximum curvature and the minimum curvature in each direction at each position on the lens surface by the refractive index of the lens material.

[0181] In this specification, the surface astigmatism distribution is the distribution of values obtained by multiplying the difference between the maximum curvature and the minimum curvature in each direction at each position on the lens surface by the refractive index of the lens material.

[0182] It should be noted that Figure 9 The two distribution diagrams shown are about the lens surface. Figure 9 In the surface average power distribution diagram shown, the surface average power for distance vision is set to +4.00D, the surface average power for near vision is set to +6.00D, and the added power ADD is set to 2.00D. It is assumed that both distribution diagrams are reflected on the object-side surface, i.e., the outer surface. The same applies to the following embodiments.

[0183] However, the specific examples in this specification are merely examples. The inner surface on the eyeball side can have a shape that reflects the distribution pattern, or both surfaces can be designed by assigning the progressive components that contribute to the distribution patterns to both surfaces. In this case, the inner surface on the eyeball side can have a spherical shape or an aspherical shape that reduces off-axis aberrations.

[0184] There are many advantages that can be gained by assuming a unified eye. These advantages are described below.

[0185] Both right- and left-eye lenses are designed with consideration given to the amount of inset. This amount of inset varies depending on the prescription's spherical power, cylindrical power, addition power, prismatic power, interpupillary distance, and other factors. Furthermore, by setting the inset, the principal line of sight shifts toward the nose. Consequently, the near reference point 230 also shifts horizontally to one side.

[0186] On the other hand, since the center of rotation of the unifying eye is set at the middle position between the right eye and the left eye, there is no need to add inset. Figure 9 As shown, if it is a unified ophthalmic lens, the main gaze line is consistent with the meridian.

[0187] It should be noted that the meridian is also a vertical line passing through the midpoint of the positions of the two hidden marks set on the progressive refractive power lens. In addition, the meridian is also the Y axis of the distribution graph.

[0188] That is, the average refractive power distribution diagram and the astigmatism distribution diagram of the integrated ophthalmic lens are simpler than those of the right-eye lens and the left-eye lens.

[0189] This is useful for making the difference V in the progressive-power lens close to the difference W in the reference single-focus lens or the naked eye. First, the average refractive power distribution diagram and astigmatism distribution diagram of the combined eye lens with a large head are changed. On this basis, the progressive-power lenses for the left and right eyes are designed taking into account the amount of inward deviation of the left and right eyes (for example, the following Figure 14 ), based on this design, it is sufficient to study whether the difference V is close to the difference W (advantage 1).

[0190] This (Advantage 1) is particularly important in the case of progressive-power lenses with different prescriptions for the left and right eyes. This is because, even in cases where the left and right prescriptions differ, the average refractive power profile and astigmatism profile of the large-head integrated ophthalmic lens can be first changed, and then, based on this, the progressive-power lenses for the left and right eyes can be designed to take into account the different prescriptions for the left and right eyes. Compared to designing each progressive-power lens for the left and right eyes with the difference in prescription and amount of inward deviation taken into account from the outset, this method of one embodiment of the present invention saves considerable effort.

[0191] Furthermore, since the average refractive power distribution diagram and astigmatism distribution diagram of the integrated lens are used as the main head, there is an advantage in being able to understand the difference between the integrated lens and the right eye lens (for example, eye position difference). Similarly, the difference between the integrated lens and the left eye lens can also be understood (Advantage 2).

[0192] Summarizing the above structure, we can get the following expression.

[0193] "The angle difference VA is Figure 8A The difference between the angle difference VAR between the right eye sight direction and the integrated eye sight direction and the angle difference VAL between the left eye sight direction and the integrated eye sight direction in the progressive frontal viewing state A shown in ,

[0194] The angle difference VB is Figure 8B The difference between the angle difference VBR between the right eye sight direction and the integrated eye sight direction and the angle difference VBL between the left eye sight direction and the integrated eye sight direction in the progressive side viewing state B shown in ,

[0195] The angle difference VC is Figure 8C The difference between the angle difference WCR between the right eye sight direction and the integrated eye sight direction and the angle difference WCL between the left eye sight direction and the integrated eye sight direction in the reference front viewing state C shown in ,

[0196] The angle difference WD is Figure 8D The difference between the angle difference WDR between the right eye sight direction and the integrated eye sight direction and the angle difference WDL between the left eye sight direction and the integrated eye sight direction in the reference side observation state D is shown in .

[0197] Figure 10 This is a schematic diagram showing the position of the target object surface seen by the wearer of progressive-power lenses, namely, right-eye lenses, left-eye lenses, and integrated eye lenses, when viewed vertically downward from vertically above, using a design method according to one embodiment of the present invention.

[0198] Regarding the deformation in the depth direction described in the technical problem column, the same is true when using the unified eye as when not using the unified eye. Figure 6 Likewise, the depth offset disappears or nearly disappears between frontal and side views.

[0199] Regarding the (upper and lower eye level difference) mentioned in the technical question column, the difference is also the same when using the unified eye and when not using the unified eye. Figure 7 Similarly, the vertical eye position difference when looking from the side disappears or almost disappears. Figure 7 The corresponding figure and Figure 7 The contents are the same, so they are omitted.

[0200] It should be noted that according to (Advantage 2), when adjusting the surface shape of the progressive-power lens, the correction amount for the right-eye lens and the correction amount for the left-eye lens vary according to the two differences. A specific example of this structure is expressed as follows.

[0201] "When adjusting the surface shape of the progressive-power lens, the correction amount of the progressive-power lens for the right eye and the correction amount of the progressive-power lens for the left eye are proportionally distributed based on at least any one of the ratio of the angle difference VAR to the angle difference VAL, the ratio of the angle difference VBR to the angle difference VBL, the ratio of the angle difference WCR to the angle difference WCL, and the ratio of the angle difference WDR to the angle difference WDL."

[0202] It should be noted that if only the angle difference VB in the progressive side viewing state B when the progressive-power lens is worn is varied, the difference V can be limited to a predetermined permissible range of the distance difference W. Based on this understanding, it is preferable to proportionally distribute the correction amount based on the ratio of the angle difference VBR to the angle difference VBL in each ratio. Furthermore, the correction amount may be proportionally distributed not strictly based on the ratio, but by applying some weighting.

[0203] Furthermore, according to (Advantage 2), for example, one embodiment of the present invention can be applied to both a right-eye lens and a left-eye lens.

[0204] get Figure 8AThe angle difference VAR between the right eye sight direction and the integrated eye sight direction in the progressive frontal viewing state A is shown, and Figure 8B The difference VR is the angular difference VBR between the right eye sight line direction and the integrated eye sight line direction in the progressive side viewing state B shown.

[0205] Similarly, we get Figure 8C The angle difference WCR between the right eye sight direction and the integrated eye sight direction in the reference front viewing state C is shown, and Figure 8D The difference WR shown is the angular difference WDR between the right eye sight line direction and the integrated eye sight line direction in the reference side viewing state D.

[0206] Then, the progressive-power lens is designed so that the difference VR approaches the difference WR. This reduces the influence of the unnecessary prismatic effect caused by the progressive effect on the right-eye lens.

[0207] By designing the progressive-power lens in exactly the same manner for the left-eye lens, the influence of the unnecessary prismatic effect caused by the progressive effect on the left-eye lens is reduced.

[0208] In this method, an aspect of the present invention is applied to each of the right-eye lens and the left-eye lens based on the angular difference with the integrated ophthalmic lens. This allows for more rigorous reduction of the effects of unwanted prismatic effects caused by the progressive effect. Consequently, a more comfortable wearing experience is achieved.

[0209] [Modification of the method for designing a progressive-power lens according to one embodiment of the present invention]

[0210] In one embodiment of the present invention, an example is given of grasping the difference V between the progressive front viewing state A and the progressive side viewing state B, grasping the difference W between the reference front viewing state C and the reference side viewing state D, and designing the lens surface shape in such a way that the difference V approaches the difference W.

[0211] If this is expressed as a mathematical formula, it is (A-B)-(C-D). Alternatively, this mathematical formula can be expressed as (A-C)-(B-D).

[0212] Specifically, the lens surface shape can be designed so that the difference V' approaches the difference V' by understanding the difference between the progressive frontal viewing state A and the reference frontal viewing state C, and the difference W' between the progressive lateral viewing state B and the reference frontal viewing state D. Furthermore, by varying the angular difference VB in the progressive lateral viewing state B, the difference W' can be limited to a predetermined permissible range of the distance difference V'. Preferred examples of this predetermined permissible range are the same as those described in [Details of the Method for Designing a Progressive-Power Lens According to One Aspect of the Present Invention].

[0213] However, even when this modification is adopted, as shown in the above-mentioned mathematical formula, the result does not change even when the difference V is brought closer to the difference W, and does not change even when the difference V is limited to a predetermined allowable range from the difference W. That is, the configurations described in [Method for Designing Progressive-Power Lenses According to One Aspect of the Present Invention] and [Details of the Method for Designing Progressive-Power Lenses According to One Aspect of the Present Invention] also include this modification.

[0214] It should be noted that, as in one embodiment of the present invention, by using a combination of the difference V between the progressive front view state A and the progressive side view state B, and the difference W between the reference front view state C and the reference side view state D, only the reference single-vision lens is reflected in the difference W. In other words, only the target value is reflected in the difference W. By making the difference V, which reflects only the progressive-power lens, close to this difference W, the effects of the present invention can be achieved. Therefore, it is preferable to use the difference V and the difference W.

[0215] It should be noted that it may be expressed as (A+D)-(B+C), but considering that only the target value is reflected in the difference W, it is preferable to consider it based on (A-B)-(C-D).

[0216] [A specific example (system) of a method for designing a progressive-power lens according to one embodiment of the present invention]

[0217] The following describes a specific example of applying the above-mentioned progressive-power lens design method to a system. This example illustrates the use of a unified eye. It should be noted that any overlap with the content described so far has been omitted. Furthermore, this example illustrates the design of a right-eye lens and a left-eye lens. Therefore, for ease of explanation, both lenses are sometimes referred to as a lens pair. Furthermore, a reference single-focus lens is sometimes referred to as a reference lens, and a unified eye lens is sometimes referred to as an integrated lens.

[0218] Figure 11 This is a diagram illustrating an example of a system for implementing a method for designing a progressive-power lens according to one embodiment of the present invention.

[0219] Figure 11 The illustrated system 50 includes a plurality of optical shop terminals and a lens pair design device (hereinafter also referred to as a design device or a computer device) 60 for progressive-power lenses. The following configuration is controlled by a control unit (not shown).

[0220] exist Figure 11 In the embodiment, the optical shop terminal exemplifies the optical shop terminal 52 and the optical shop terminal 54. The optical shop terminals 52 and 54 are Figure 11In the example shown, the lens processing device 56 is connected to the design device 60 via a WAN (Wide Area Network) or the Internet. The design device 60 is connected to the lens processing device 56, and the design information of the progressive-power lens designed by the design device 60 is transmitted to the lens processing device 56. The lens processing device 56 processes the lens surface based on the design information to produce the progressive-power lens.

[0221] Information for producing a progressive-power lens for a customer is input to the optical shop terminal 52 and transmitted via the WAN or the Internet to the design device 60. The design device 60 designs the progressive-power lens 10 using the transmitted information.

[0222] The information used to produce the progressive-power lens 10 includes at least prescription information about the eyes of a wearer who is scheduled to wear the progressive-power lens 10 , product information of the progressive-power lens, and frame information for wearing the progressive-power lens.

[0223] The prescription information includes, for example, the spherical power (also called average power) S at the distance reference point of the right-eye lens 10R and the left-eye lens 10L, the cylindrical power C at the distance reference point, the astigmatism axis Ax, the addition power ADD at the progressive refractive power lens, the prism power and base direction, the pupil distance PD, physiological characteristics related to the wearer's visual perception, the visual environment, and other information.

[0224] Product information includes information related to the lens design type, progressive zone length, lens diameter, lens wall thickness, etc. For example, in the case of progressive power lenses, the design type may be a lens that prioritizes distance vision, a lens that prioritizes near vision, or a lens that is hardware-designed or software-designed.

[0225] The frame information includes various information such as the shape and size of the frame sphere, the frame material, the position of the eye point, the frame forward tilt angle, the frame warp angle, and the distance between vertices.

[0226] Figure 12 This is a structural diagram showing the device configuration of a design device in a system for implementing a method for designing a progressive-power lens according to one embodiment of the present invention.

[0227] The design device 60 is constituted by a computer including a CPU 62, a ROM 64, a RAM 66, and a communication unit 68. The communication unit 68 is connected to the eyewear store terminals 52 and 54 via a WAN or the Internet.

[0228] Specifically, a computer executes a method for producing a progressive-power lens as a design device 60. An input operation unit 70, such as a mouse or keyboard, and a display 71 are connected to the design device 60. An operator inputs parameters or information via the input operation unit 70 based on an input screen displayed on the display 71, thereby enabling the design process described below to be executed.

[0229] The design device 60 calls a program stored in the ROM 64 and causes the CPU 62 to execute the program, thereby forming and validating a software module 72 .

[0230] The software module 72 includes an integrated lens design unit 72a, a target object plane setting unit 72b, a lens pair design unit 72c, a reference lens design unit 72d, a sight line calculation unit 72e, a determination unit 72f, a surface shape adjustment unit 72g, and a lens surface design unit 72h.

[0231] Integrated lens design department 72a design Figure 10 The integrated eye 12M and the integrated eye lens 10M shown are produced Figure 9 The surface average power distribution and surface astigmatism distribution of the integrated ophthalmic lens 10M are shown.

[0232] The target object plane setting unit 72 b is a portion that determines the finite distance when the wearer gazes at the target object plane 22 (actual plane 22 ) at a finite distance from the progressive-power lens 10 and sets the actual plane 22 .

[0233] The lens pair design unit 72c is a part that performs initial design of the right-eye lens and the left-eye lens based on the prescription information. As an example, the lens surface shape determined based on the prescription information is used as the initial design.

[0234] The reference lens designing unit 72d designs a reference single-focal lens. In this example, a reference point single-focal lens having the same spherical equivalent power (S+C / 2) as the single-focal lens and the progressive-power lens is designed.

[0235] It should be noted that when a lens with a spherical power of zero, i.e., a zero-power lens, is used instead of the reference single-focus lens, the reference lens design portion 72d may also be used. Furthermore, when the lens is viewed with the naked eye, the reference lens design portion 72d may not be used. Of course, even when the lens is viewed with the naked eye, the other components for obtaining the difference W are still used.

[0236] The sight line calculation unit 72e calculates the position O ( ) on the actual surface 22 that is viewed through the right-eye lens and the left-eye lens, which are the progressive-power lenses of the initial design. Figure 8A 、 Figure 8C ) and its lateral part P( Figure 8B 、 Figure 8D ) when viewing the image.

[0237] The sight line calculation unit 72e also calculates the Figure 10 The illustrated unifying eye 12M and the unifying lens 10M show the direction of the line of sight of the unifying eye 12M when the unifying eye 12M is looking at the portion O and the portion P to the side of the portion O on the actual surface 22 .

[0238] The sight line calculation unit 72e further calculates the sight line directions of the right eye 12R and the left eye 12L when the right eye 12R and the left eye 12L look at the portion O and the lateral portion P on the actual surface 22 through the reference single-vision lenses for the right eye and the left eye.

[0239] The determination unit 72f determines whether the difference V is close to the difference W. For example, the determination unit 72f determines whether the difference V is within a predetermined allowable range of the distance difference W.

[0240] When the determination result of the determination unit 72f is NG, the surface shape adjusting unit 72g adjusts the lens surface shapes of the initially designed right-eye lens and left-eye lens.

[0241] In this manner, the design device 60 adjusts the lens surface shape using the surface shape adjusting unit 72g and the sight line calculating unit 72e until the judging unit 72f obtains an OK judgment result.

[0242] The lens surface design unit 72h uses the lens surface shape for which the determination unit 72f has determined that it is OK, and specifically performs surface design on both sides of the lens surface.

[0243] It should be noted that one can appropriately choose whether to use an inner surface progressive refractive power lens that includes a progressive component with an addition power added to the lens surface on the eyeball side, an outer surface progressive refractive power lens that includes a progressive component with an addition power added to the lens surface on the side opposite to the eyeball side, or a two-sided progressive refractive power lens that distributes the progressive component to both the lens surface on the eyeball side and the lens surface on the side opposite to the eyeball side.

[0244] Figure 13 This is a diagram showing the flow of a method for designing a progressive-power lens according to one embodiment of the present invention.

[0245] First, the design device 60 receives an order for production of the progressive-power lens 10 from the optical shop terminals 52 and 54 (step S10). The order includes prescription information, product information, and frame information of the wearer who ordered the progressive-power lens 10.

[0246] The integrated lens design unit 72a uses the prescription information included in the received order and further uses the product information to assume the integrated eye 12M. Figure 9As shown, the unified eye lens 10M is designed for the unified eye 12M (step S12).

[0247] Next, the target object plane setting unit 72 b determines the finite distance and sets the target object plane 22 (actual plane 22 ) (step S14 ).

[0248] Figure 14 This is a diagram showing an example of the surface astigmatism distribution of the right-eye lens 210R and the left-eye lens 210L initially designed while inwardly deviating the surface astigmatism distribution of the combined ophthalmic lens.

[0249] Next, the lens pair design unit 72c performs initial design of progressive addition lenses for the right eye and the left eye (step S16). Figure 14 As shown, the lens pair design unit 72 c inwardly deflects the combined ophthalmic lens 10M to generate a surface average power distribution and a surface astigmatism distribution.

[0250] As needed, the lens pair design unit 72c corrects the surface average power distribution and surface astigmatism distribution of the initially designed right-eye and left-eye lenses based on the cylindrical power C and added power ADD of the right eye and left eye, and determines the lens surface shape that achieves the correction result.

[0251] Next, the sight line calculation unit 72e calculates the part P on the actual surface 22 that the sight line of the unified eye 12M reaches when the unified eye 12M observes a portion corresponding to a predetermined distance (e.g., 40 cm) from the wearer on the actual surface 22 through the unified eye lens 10M (step S18). It should be noted that the position coordinates of the part O can be determined at the stage where the predetermined distance is determined to be 40 cm. To reiterate, the part P is a part that is at the same vertical height as the part O and is located to the side of the part O in the horizontal direction.

[0252] Specifically, the method for calculating the part P is to change the sight line of the unified eye 12M by giving an inclination angle θ relative to the Z direction (depth direction) of the front view, and calculate the position coordinates of the part P on the actual surface 22 where the sight line reaches at this time.

[0253] It should be noted that by changing the tilt angle θ, Figure 5 Multiple points P (e.g., points P1, P2, P3, ..., collectively referred to as P) are calculated horizontally on the target object plane 20, corresponding to a predetermined distance of 40 cm from the wearer. The following calculations are performed on each calculated point P regarding the gaze direction of the right eye, left eye, and combined eye.

[0254] At this time, the line of sight is refracted by the prism action of the unifying lens 10M. The amount of refraction varies depending on which part of the unifying lens 10M the line of sight passes through. The tilt angle of the unifying eye's line of sight with respect to the Z direction and the position coordinates of the part P are stored in the RAM 66.

[0255] Next, the sight line calculation unit 72e calculates the sight line directions of the right eye 12R and the left eye 12L on the eyeball side when the right eye 12R and the left eye 12L are looking at each point P on the actual surface 22 using the initially designed right-eye lens 210R and the left-eye lens 210L, using the same method as the sight line directions in the integrated eye lens (step S20). The tilt angles of the sight lines of the right eye 12R and the left eye 12L with respect to the Z direction and the position coordinates of the position P are then stored in the RAM 66.

[0256] Next, the sight line calculation unit 72e calculates the sight line directions of the right eye 12R, the left eye 12L, and the unified eye when looking at the point O on the median plane using the same method as used for the sight line directions relative to the point P (step S22). The tilt angles of the sight lines of the right eye 12R, the left eye 12L, and the unified eye relative to the Z direction are stored in the RAM 66.

[0257] Meanwhile, the reference lens design unit 72d designs a reference single-vision lens for the right eye and a reference single-vision lens for the left eye (step S26). This step can be performed during, before, or after the design device 60 executes steps S16 to S24.

[0258] Next, the sight line calculation unit 72e calculates the position P at which the sight line of the unified eye 12M reaches the actual surface 22 when the unified eye 12M observes the actual surface 22 through the unified eye single-vision lens 30M (step S28). This step is similar to step S18 described above, and therefore this processing can be omitted. Step S28 performs the same processing as step S18, and therefore its description is omitted.

[0259] Furthermore, the sight line calculation unit 72e calculates the sight lines when looking at points on the actual surface 22 with reference to the single-focus lens, and the sight line directions of the right eye 12R, left eye 12L and unified eye 12M corresponding to each part P on the actual surface 22 (step S30).

[0260] Furthermore, the sight line calculation unit 72e calculates the sight line directions of the right eye 12R and the left eye 12L when the single-vision lenses 30L and 30R are looking at the position O on the actual surface 22 (step S32). Specifically, the sight line calculation unit 72e calculates the tilt angles of the left eye 12L and the right eye 12R with respect to the Z direction. The position coordinates of the position O and the calculated tilt angles of the left eye 12L and the right eye 12R are stored in the RAM 66.

[0261] It should be noted that the order of steps S16 to S22 and steps S26 to S32 is not particularly limited. Alternatively, step S26 may be performed after step S16, followed by step S18, and then alternately performed with steps S28, S20, S30, and so on. Furthermore, the order of the processing of step S14 and steps S16 and S26 may be reversed.

[0262] The determination unit 72f retrieves the stored tilt angles indicating each sight line direction and the position coordinates of the part O from the RAM 66, calculates the difference between the sight line directions, and performs determination (step S34). This determination is performed for each part P.

[0263] Furthermore, the predetermined distance may be varied from 40 cm, and similar operations may be performed to identify the portion O, calculate each portion P, and calculate the gaze directions of the right eye, left eye, and unified eye. In this case, the determination unit 72 f also determines each portion P when the predetermined distance is varied from 40 cm.

[0264] When the determination result of the determination unit 72 f is NG, the surface shape adjusting unit 72 g adjusts the lens surface shapes of the initially designed left-eye lens 210L and the right-eye lens 210R (step S36 ).

[0265] When the determination result of OK is obtained by the determination unit 72 f for all the parts P, the adjusted lens surface shape is determined as the lens surface shape for the final progressive-power lens 10 .

[0266] Figure 15 1 and 2 are diagrams showing an example of changes in the surface average power distribution and the surface astigmatism distribution on the lens surfaces before and after adjustment when the left-eye lens 210L and the right-eye lens 210R are progressive-power lenses.

[0267] Finally, the lens surface design unit 72h determines the lens surface shape (having Figure 15 ), surface design is performed on both sides of the progressive power lens (step S38).

[0268] In this way, the information on the surface design of both surfaces is sent to the lens processing device 56 , and the actual progressive-power lens 10 is manufactured.

[0269] [Design System for Progressive-Power Lenses According to One Embodiment of the Present Invention]

[0270] The present invention also has technical significance as a design system for progressive-power lenses. Its specific structure is described below. It should be noted that the various aspects of one embodiment of the present invention described below may be appropriately combined with the preferred examples described herein.

[0271] "A system for designing a progressive-power lens, comprising a software module for adjusting the surface shape of the progressive-power lens so that the difference V approaches the difference W,

[0272] The difference V is the difference between a state A and a state B when the progressive refractive power lens is worn, wherein the state A is a state when the wearer visually sees an object at a portion O on the median plane of the wearer at a limited distance in front of the wearer, and the state B is a state when the wearer visually sees an object at a portion P on a plane parallel to the frontal plane and containing the portion O at the same vertical height as the portion O and located to the side of the portion O in the horizontal direction.

[0273] The difference W is the difference between a state C when wearing a reference single-focus lens corresponding to a progressive-power lens or when wearing the lens with the naked eye, and a state D when visually observing an object at the portion O and visually observing an object at the portion P.

[0274] [Program of a progressive-power lens design system according to one embodiment of the present invention]

[0275] The present invention also has technical significance as a program for a design system of progressive-power lenses (hereinafter also referred to as a "program" for short).

[0276] “A program for a method of designing a progressive-power lens, which causes a computer (software module) to operate in such a manner that the surface shape of the progressive-power lens is adjusted so that the difference V approaches the difference W,

[0277] The difference V is the difference between a state A and a state B when the progressive refractive power lens is worn, wherein the state A is a state when the wearer visually sees an object at a portion O on the median plane of the wearer at a limited distance in front of the wearer, and the state B is a state when the wearer visually sees an object at a portion P on a plane parallel to the frontal plane and containing the portion O at the same vertical height as the portion O and located to the side of the portion O in the horizontal direction.

[0278] The difference W is the difference between a state C when wearing a reference single-focus lens corresponding to a progressive-power lens or when wearing the lens with the naked eye, and a state D when visually observing an object at the portion O and visually observing an object at the portion P.

[0279] [Method for Manufacturing Progressive-Power Lenses According to One Embodiment of the Present Invention]

[0280] A method for manufacturing a progressive-addition lens according to one embodiment of the present invention includes a design step using the progressive-addition lens design method described above, and a processing step for obtaining the progressive-addition lens after the design step. The specific details of the manufacturing method may be known.

[0281] [Progressive-power lens according to one embodiment of the present invention]

[0282] The present invention also has technical significance as a progressive-power lens. The specific structure is as follows.

[0283] "A progressive-power lens comprising: a near portion having a refractive power for near vision; a distance portion having a refractive power for viewing objects farther away than near vision; and an intermediate portion having a progressive effect in which the refractive power gradually changes between the distance portion and the near portion;

[0284] The lens is provided with a prismatic effect adjustment area that reduces the degree of image distortion caused by the unnecessary prismatic effect due to the progressive effect to a degree close to that of image distortion when wearing a reference single-focus lens corresponding to a progressive-power lens or when wearing the lens with the naked eye.

[0285] The so-called "degree of image deformation caused by unnecessary prismatic effect due to the progressive effect" corresponds to, for example, deformation in the depth direction and / or vertical eye position difference in the content described in relation to [a method for designing a progressive refractive power lens according to one embodiment of the present invention].

[0286] The phrase "making the degree of image deformation due to the unnecessary prismatic effect caused by the progressive effect approach the degree of image deformation when wearing a reference single-focus lens corresponding to the progressive-power lens or when wearing the lens with the naked eye" refers to the state of designing the lens surface shape so that the difference V approaches the difference W as described in "Details of the design method of a progressive-power lens according to one embodiment of the present invention."

[0287] Preferably, the prismatic action adjustment region includes a region laterally offset from the main viewing line in the horizontal direction.

[0288] In addition, it is preferable that the position of the prescribed horizontal cross section is a position where the addition degree reaches 85% to 100%.

[0289] Furthermore, the progressive-power lens according to one embodiment of the present invention preferably satisfies at least one of the following two conditions, and more preferably satisfies both conditions.

[0290] [Condition 1]

[0291] In a diagram plotted with the horizontal direction of the lens as the horizontal axis and the surface prism difference in the vertical direction normalized by the addition as the vertical axis, the difference between the maximum and minimum values of the surface prism difference in the vertical direction at a predetermined portion α on a predetermined horizontal cross-section in the near portion is 0.2 [prism diopters / diopters] or greater;

[0292] [Condition 2]

[0293] In a plotting diagram with the lens' horizontal direction as the horizontal axis and the surface prism difference in the horizontal direction normalized by addition as the vertical axis, at x = 0 within a predetermined portion γ on a predetermined horizontal cross-section in the near portion, the absolute value of the surface prism difference in the horizontal direction is 0.25 [prism diopters / diopters] or greater. The position x = 0 within the predetermined portion γ is located directly below the prism reference point or directly below the midpoint of the two alignment reference marks of the progressive-power lens. Note that x = 0 is the prism reference point or a plumb line including the midpoint. The setting of x = 0 in plotting the surface prism difference throughout this specification will remain the same.

[0294] Regarding [Condition 1], this condition primarily relates to reducing vertical eye position difference. In one embodiment of the present invention, when a pair of progressive-power lenses is used, objects are viewed through the pair of progressive-power lenses. In this case, the vertical surface prism difference is defined as the difference between the vertical prism power of area α on the right-eye lens, through which the right eye's line of sight passes, and the vertical prism power of area β on the left-eye lens, through which the left eye's line of sight passes.

[0295] The method for obtaining the surface prism difference in the vertical direction when using a pair of progressive power lenses is as follows. It should be noted that, in this specification, "normalized by addition" means the surface prism power of the lens divided by the addition set for the lens. Moreover, the specific numerical limits of the prism power (prism power) in this specification are all set to values normalized by addition. For example, "the surface prism difference in the vertical direction normalized by addition" means, if the following paragraph is used as an example, "the value obtained by subtracting the prism power (surface prism power) in the vertical direction normalized by addition at a specified portion α from the prism power (surface prism power) in the vertical direction normalized by addition at a specified portion β".

[0296] (Method for obtaining surface prismatic aberration in the vertical direction when using a pair of progressive-power lenses)

[0297] 1. Using the origin as the midpoint of the two hidden marks on the progressive-power lens, determine the specified position α, a distance d in the horizontal direction x, from the principal gaze line on the right-eye lens (at y = -14 mm, which includes the near reference point), in the lens surface prism power distribution standardized by the addition power relative to the progressive-power lens.

[0298] 2. Determine a predetermined position β that is a distance d away from the principal gaze line on the left-eye lens (at y = -14 mm, which includes the near reference point) in the direction -x opposite to the horizontal direction x.

[0299] 3. The value obtained by subtracting the prism power in the vertical direction of the predetermined portion β from the prism power in the vertical direction of the predetermined portion α is defined as the surface prism difference in the vertical direction of the predetermined portion α.

[0300] It should be noted that even if it is not a pair of progressive addition lenses but a single progressive addition lens, [Condition 1] can be stipulated if the prescription powers of the left and right lenses are the same. This is because, if the prescription powers of the left and right lenses are the same, by making the right eye lens mirror-symmetrical (as described later), Figure 17 As shown in the figure, the lens is bilaterally symmetrical when viewed from the front and is used for the left eye. On a single progressive-power lens, a predetermined area α and a predetermined area β can be set. This concept led to the following expression.

[0301] (Method for obtaining vertical surface prismatic aberration when using a progressive-power lens)

[0302] 1. Taking the origin as the midpoint of the two hidden marks on the progressive-power lens, determine the horizontal direction x and distance d from the principal gaze line of a specified portion α in the lens surface prism power distribution standardized by addition relative to the progressive-power lens.

[0303] 2. Determine a predetermined position β that is a distance 2d away from the predetermined position α in the opposite direction -x to the direction x.

[0304] 3. The value obtained by subtracting the prism power in the vertical direction of the predetermined portion β from the prism power in the vertical direction of the predetermined portion α is defined as the surface prism difference in the vertical direction of the predetermined portion α.

[0305] As shown in Example 3, when plotting the lens horizontally along the horizontal axis and the vertical surface prism difference along the vertical axis, a progressive-power lens with a difference between the maximum and minimum vertical surface prism difference of 0.2 [prism diopters / diopters] or greater is found. This is a characteristic not found in conventional progressive-power lenses. This is intentionally achieved in one embodiment of the present invention to reduce vertical eye position difference.

[0306] Regarding [Condition 2], this condition primarily relates to reducing distortion in the depth direction. In one embodiment of the present invention, when a pair of progressive-power lenses is used, an object is viewed through the pair of progressive-power lenses. In this case, the horizontal surface prism difference is defined as the difference between the horizontal prism power of a portion γ on the right-eye lens through which the right eye's line of sight passes and the horizontal prism power of a portion δ on the left-eye lens through which the left eye's line of sight passes.

[0307] The method of obtaining the surface prism difference in the horizontal direction in the case of using a pair of progressive-power lenses is as follows.

[0308] (Method for obtaining surface prismatic aberration in the vertical direction when using a pair of progressive-power lenses)

[0309] 1. Taking the origin as the midpoint of the two hidden marks on the progressive-power lens, determine a specified location γ (e.g., y = -14 mm and x = 0) on a specified horizontal section in the near portion of the lens surface prism power distribution standardized by addition relative to the progressive-power lens.

[0310] 2. Determine a predetermined location δ (for example, y=-14 mm and x=0) on a predetermined horizontal cross section in the near portion of the left-eye lens.

[0311] 3. The value obtained by subtracting the prism power in the horizontal direction of the predetermined portion δ from the prism power in the horizontal direction of the predetermined portion γ is defined as the surface prism difference in the horizontal direction.

[0312] It should be noted that even if a single progressive-addition lens is used instead of a pair of progressive-addition lenses, [Condition 2] can be established if the prescription diopters for the left and right lenses are the same. This is because, if the prescription diopters for the left and right lenses are the same, by making the right-eye lens bilaterally symmetrical, the prescribed area γ and the prescribed area δ can be set on the single progressive-addition lens. This concept led to the following expression.

[0313] (Method for obtaining horizontal surface prismatic aberration when using a single progressive-power lens)

[0314] 1. Taking the origin as the midpoint of the two hidden marks on the progressive-power lens, determine a specified location γ (e.g., y = -14 mm and x = 0) on a specified horizontal section in the near portion of the lens surface prism power distribution standardized by addition relative to the progressive-power lens.

[0315] 2. The absolute value of twice the value of the prism power in the horizontal direction of the predetermined portion γ is taken as the surface prism difference in the horizontal direction of the predetermined portion γ.

[0316] When the prescription power of the left and right lenses is the same, the shapes of the left and right lenses are mirror-symmetrical. If the horizontal prism power at y = 14 mm and x = 0 in the right-eye lens is 0.15 [prismatic diopters], the horizontal prism power at the same portion of the left-eye lens is -0.15 [prismatic diopters]. As a result, the absolute value of the horizontal surface prism difference is 0.30 [prismatic diopters].

[0317] As shown in Example 1 below, a progressive-power lens with an absolute value of horizontal surface prism difference of 0.25 [prism power / diopter] or greater at x = 0 when y = -14 mm is a feature not found in conventional progressive-power lenses. This is intentionally achieved in one embodiment of the present invention to reduce distortion in the depth direction.

[0318] It should be noted that it is also preferable to satisfy the following conditions.

[0319] [Condition 3]

[0320] The plot of the progressive-addition lens with the line of sight direction (tanθ) as the horizontal axis and the depth position information (unit: diopter) as the vertical axis does not intersect with the plot when a reference single-focal lens corresponding to the progressive-addition lens is worn or when viewed with the naked eye.

[0321] Regarding [Condition 3], this condition primarily relates to reducing deformation in the depth direction. Therefore, [Condition 3] can be applied in place of [Condition 2], which relates to reducing deformation in the depth direction, or both [Condition 2] and [Condition 3] can be applied simultaneously. As shown in Example 1 below, the following content indicates that a plot of a progressive-addition lens with line of sight (tanθ) on the horizontal axis and depth-direction position information (unit: diopters) on the vertical axis does not intersect with a plot of a reference single-focal lens corresponding to the progressive-addition lens when worn or when viewed with the naked eye.

[0322] That is, regardless of the direction of vision, when comparing one lens to the other, the image of an object formed through the reference lens or the lens according to one embodiment of the present invention always exists in either the depth direction or the near-forward direction. This helps reduce distortion in the depth direction. As a result, the effects of unnecessary prismatic effects caused by the progressive effect are reduced, resulting in a comfortable wearing experience.

[0323] Example

[0324] Next, the present invention will be described in detail with reference to Examples. However, the present invention is not limited to the following Examples.

[0325] (Common to all embodiments)

[0326] In the following examples, a pair of progressive-power lenses (hereinafter referred to as a pair of eyeglass lenses) was manufactured. The eyeglass lens pair manufactured in each example had the following structure.

[0327] That is, regarding the progressive-power lens pair consisting of a right-eye lens and a left-eye lens,

[0328] The right-eye lens and the left-eye lens of the progressive-power lens pair include: a distance portion having a power set for distant observation; a near portion having a near power set by adding an add-on power to the distance power for near observation; and an intermediate portion having a power that gradually changes between the distance portion and the near portion.

[0329] At this time, the right-eye lens and the left-eye lens have prism adjustment areas, which make the deformation of the image caused by the prism effect of the eyeglass lens, specifically, the difference between the prism effects of the left-eye lens and the right-eye lens, approximate the deformation of the image caused by the prism effect of the lens surface shape of the reference lens set based on the distance power or near power, specifically, the difference in prism effect.

[0330] The prism adjustment area includes an area for achieving near vision power, including the near vision reference points of each lens of the right eye lens and the left eye lens, and the area outside the plumb line passing through the midpoint of two hidden marks set on each lens of the right eye lens and the left eye lens on the horizontal line of the near vision reference point.

[0331] Figure 16 1 and 2 are diagrams for explaining an example of a right-eye lens 300 in a pair of spectacle lenses according to each embodiment.

[0332] Figure 16 Hidden marks 302 and 304 are shown. Hidden marks 302 and 304 are alignment reference marks as specified in JIS. Hidden marks 302 and 304 are located at two points 17 mm horizontally from the center of the lens. Therefore, the horizontal direction of the spectacle lens 300 and the vertical direction perpendicular thereto are determined by the hidden marks 302 and 304. The midpoint 305 of the hidden marks 302 and 304 coincides with the center of the spectacle lens 300. The principal line of sight passes vertically through the midpoint 306.

[0333] The near reference point 308 is located at a position moved vertically downward and horizontally to the side of the nose from the midpoint 306, and is usually specified by the manufacturer. For example, in the case of a progressive refractive power lens with a spherical power S of 0.00D, an addition power ADD of 2.50D, and a progressive zone length of 14mm, the near reference point 308 is located at a position moved 14mm vertically downward and 2.5mm horizontally to the side of the nose from the midpoint 306.

[0334] The prism adjustment area includes the area (near power measurement circle) that achieves near power (the power obtained by adding the additive power ADD to the spherical power S of the distance lens). This area includes the left and right areas outside the near reference point 308 and the vertical line VL passing through the midpoint 306 on the horizontal line HL passing through the near reference point 308. This area is part of the near lens and is used for viewing the lower side. Therefore, it is prone to image distortion in the depth direction caused by the difference in the prismatic effect on the lines of sight of the left and right eyes. Therefore, the prism adjustment area includes the left and right areas outside the vertical line VL on the horizontal line HL.

[0335] Furthermore, according to one embodiment of the present invention, the prism adjustment area preferably includes a near reference point. At the near reference point, the addition ADD or the reference addition indicated by the manufacturer is 100%. Distortion of the image in the depth direction caused by the difference in prism action, or an uncomfortable wearing feeling, is particularly noticeable in the area surrounding the near reference point. Therefore, the prism adjustment area preferably includes the near reference point.

[0336] Figure 17 1 and 2 are diagrams for explaining a method of calculating a difference value distribution from the prism refractive power distributions on the lens surfaces of the right-eye lens 300 and the left-eye lens 400 .

[0337] Here, we'll focus on the prismatic refractive power distribution of nickel surfaces normalized by the addition factor ADD. The prismatic refractive power of a lens surface normalized by the addition factor ADD is defined as the vertical slope multiplied by (refractive index of the lens material - 1) × 100 [prismatic diopter] / addition factor ADD [diopter]. The slope is a dimensionless value.

[0338] In the lens surface prism power distributions of the right-eye lens 300 and the left-eye lens 400 standardized by the addition ADD, the origin of the lens surface prism power distributions is set as the midpoint 306 .

[0339] Furthermore, in the standardized lens surface prism power distribution, the distribution of the difference between the vertical component of the lens surface prism power distribution of the right-eye lens 300 and the vertical component of the lens surface prism power distribution of the left-eye lens 410 in a horizontal cross-section of the near portion of the right-eye lens 300 and the left-eye lens 400 (the vertical surface prism difference, hereinafter referred to as the same) is divided into a first region and a second region, with a vertical line passing through the origin (midpoints 306 and 406) as the boundary. The near portion can be, for example, regions 310 and 410 within a range of predetermined distances vertically above and below the near reference points 308 and 408. The predetermined distance is, for example, within a range of 2.5 to 4 mm.

[0340] Here, the difference value is the difference between the values of the normalized prism power on the lens surface at positions 312 and 412 that are the same distance from the origin (midpoint 306, midpoint 406) to the same side (right or left) in the horizontal direction. For example, the value of the normalized prism power distribution on the lens surface for the left-eye lens 400 is subtracted from the value of the normalized prism power distribution on the lens surface for the right-eye lens 300.

[0341] Therefore, the first region is, for example, the difference between the values from the plumb line passing through the origin (midpoint 306) of the right-eye lens 300 and the right region, specifically, the difference between the values at positions 312 and 412 that are the same distance to the right in the horizontal direction from the origin (midpoint 306 and midpoint 406). The second region is, for example, the difference between the values from the plumb line passing through the origin (midpoint 306) of the right-eye lens 300 and the left region, specifically, the difference between the values at positions 313 and 413 that are the same distance to the left in the horizontal direction from the origin (midpoint 306 and midpoint 406).

[0342] The right-eye lens 300 and the left-eye lens 400 have prism adjustment regions in which the absolute difference between the minimum difference value in one of the first and second regions of the differential value distribution determined in this manner and the maximum difference value in the other region is 0.2 [prism diopter / diopter] or greater. This requirement corresponds to "Condition 1" described in "Progressive-Power Lens According to One Aspect of the Present Invention." That is, in each example, a pair of eyeglass lenses satisfying "Condition 1" was produced.

[0343] Here, the surface prism difference in the vertical direction is exemplified, but the surface prism difference in the horizontal direction can also be obtained by the same method.

[0344] It should be noted that, in Example 3, it is shown that [Condition 1] is satisfied as specific data. In addition, in Example 1, it is shown that the spectacle lens pairs of each example also satisfy [Condition 2].

[0345] (Example 1)

[0346] The description of the vertical axis and horizontal axis in the graph shown in the first embodiment is the same as that in the same graph in other embodiments, so the description in other embodiments is omitted. The term "graph" in this specification can also be replaced by "plot".

[0347] In the prescription information for producing the eyeglass lens pair, the spherical power S is 0.00 D [diopter], the addition power ADD is 2.50 D [diopter], the progressive zone length is 14 mm, and the refractive index is 1.60.

[0348] The distance reference point is set 8 mm vertically upward from the lens center 240 , and the near reference point is set 14 mm vertically downward from the lens center 240 and 2.5 mm horizontally toward the nose.

[0349] Figure 18 (a) shows the difference in the vertical direction of the line of sight between the two eyes when manufacturing a reference lens, the lens of Example 1, and the existing lens when installing, that is, the distribution of the eye position difference in the vertical direction, wherein the horizontal axis represents the horizontal component of the line of sight direction, and the vertical axis represents the vertical component of the line of sight direction.

[0350] Figure 18 (b) is a graph showing changes in the viewing position of the target object plane 22 in the depth direction, that is, deformation in the depth direction, where the vertical axis represents depth direction position information [diopter] and the horizontal axis represents the horizontal line of sight direction [tanθ].

[0351] Figure 18 The origin of each distribution graph shown in (a) represents the center 240 of the eyeglass lens (prism measurement point). Figure 18 The positions on the horizontal and vertical axes of each distribution graph shown in (a) represent the direction of sight observed from the midpoint M between the centers of both eyes.

[0352] Figure 19 (a) is a description Figure 18 The horizontal axis in (b) is a diagram showing the horizontal viewing direction.

[0353] like Figure 19 As shown in (a), with the center position of the integrated eye 12M as the center, the direction of front observation is set to angle θ = 0, and the angle between the direction of sight moving horizontally from the direction of front observation and the direction of front observation is set to θ, the horizontal direction of sight is represented by tanθ.

[0354] Right now, Figure 18 The area shown in (a) represents the range of the viewing angle of θ = ± 48 degrees in the horizontal direction and the vertical direction, that is, 96 degrees. Figure 18 In (a), when the sight line is θ = 48 degrees, Figure 18 The value of the horizontal axis in (b) is tanθ=1.11.

[0355] exist Figure 18 In (a), the contour level represents the vertical eye position difference between the two eyes (left eye sight direction minus right eye sight direction) in units of prism diopters. In each distribution diagram, the smaller the absolute value, the smaller the vertical eye position difference.

[0356] exist Figure 18The distribution of the difference in the vertical line of sight between the two eyes (eye position difference) shown in (a) shows that the distribution of the spectacle lens of Example 1 is closer to the distribution of the reference lens than the distribution of the conventional spectacle lens.

[0357] Figure 19 (b) is an explanation Figure 18 The vertical axis in (b) is a graph of position information in the depth direction.

[0358] like Figure 19 As shown in (b), the depth direction distance Rc of the reference intersection O as seen through the lens is calculated using the angle (convergence angle) formed by the direction of the visual lines between the two eyes when looking at the reference intersection O and the information of the pupil distance PD.

[0359] Furthermore, the angle of the line of sight when looking through the lens at the intersection point P from the front and the information on the pupillary distance PD are used to calculate the depth direction distance Ro of the intersection point P as seen through the lens. It should be noted that the distance Rc and the distance Ro are distances based on the point where the vertical plane passing through the center of the unified eye 12M and the reference intersection point O intersects the unified eye lens 10M.

[0360] Furthermore, the reciprocals of the calculated distances Rc and Ro are obtained and set as Dc and Do [diopter], respectively. Figure 18 The vertical axis of the graph shown in (b) represents depth position information [diopter] Dc-Do. A smaller Dc-Do means that the depth position of the intersection point P does not deviate from the depth position when looking at the reference intersection point O.

[0361] In addition, Figure 18 In the lens of Example 1 shown in the curve diagram shown in (b), although there is a position offset of the target object surface 22 in the depth direction compared with the reference lens, it can be seen that the change Δ1 in the position in the depth direction in the lens of Example 1 is smaller than the change Δ2 in the existing lens.

[0362] A small change Δ1 indicates a small change in the horizontal position of the target object plane 20 viewed through the lenses in the depth direction. Therefore, a wearer wearing the spectacle lens pair 10 of Example 1 is less likely to perceive depth-direction image distortion, further reducing discomfort.

[0363] In addition, Figure 18 In (b), the plots of the reference single-focus lens corresponding to the progressive-power lens when worn or when viewed with the naked eye do not intersect. In other words, the lens of Example 1 satisfies [Condition 3]. This also applies to the lens of Example 2, described later.

[0364] Furthermore, in Example 1, the above-mentioned [Condition 2] was studied, and the surface prism difference in the horizontal direction between the lens of Example 1 and the existing lens was summarized.

[0365] Figure 20 This is a graph showing changes in horizontal surface prism differences in the lens of Example 1 and conventional lenses, where the vertical axis represents horizontal surface prism differences [prism diopter / diopter], and the horizontal axis represents the x-coordinate [mm] at y=-14mm.

[0366] like Figure 20 As shown, in the lens of Example 1, at the position x=0 within the specified portion γ on the specified horizontal cross-section (y=-14mm) of the near portion, the absolute value of the surface prism difference in the horizontal direction is greater than 0.25 [prism diopter / diopter], but this is not the case in the lens of the existing example.

[0367] It should be noted that in the second and third embodiments described later, a device which is not shown in the figure but is equivalent to Figure 20 The results are as follows Figure 20 Same relationship.

[0368] By adopting the progressive-power lens design method according to one embodiment of the present invention, it was found that the lens of Example 1 could align the vertical line of sight between the two eyes, as in the reference lens. Consequently, it was found that the discomfort felt by the wearer could be reduced.

[0369] (Example 2)

[0370] In the prescription information for producing the eyeglass lens pair, the spherical power S is -4.00 D [diopter], the added power ADD is 2.50 D [diopter], the progressive zone length is 14 mm, and the refractive index is 1.60.

[0371] The distance reference point is set 8 mm vertically upward from the lens center 240 , and the near reference point is set 14 mm vertically downward from the lens center 240 and 2.3 mm horizontally toward the nose.

[0372] Figure 21 (a) shows the distribution of the difference in the vertical direction of the line of sight between the two eyes, that is, the difference in the eye position in the up-down direction, when the reference lens is used when making a pair of eyeglass lenses, the lens of Example 2, and the existing lens is installed. The horizontal axis shows the horizontal component of the line of sight direction, and the vertical axis shows the vertical component of the line of sight direction.

[0373] Figure 21(b) is a graph showing changes in the viewing position of the target object plane 22 in the depth direction, that is, deformation in the depth direction, where the vertical axis represents depth direction position information [diopter] and the horizontal axis represents the horizontal line of sight direction [tanθ].

[0374] exist Figure 21 The distribution of the difference in the visual line of sight between the two eyes (eye position difference) in the vertical direction shown in (a) shows that the distribution of the spectacle lens of Example 2 is closer to the distribution of the reference lens than the distribution of the conventional spectacle lens.

[0375] In addition, Figure 21 In the lens of Example 2 shown in the curve graph shown in (b), although there is a positional offset of the target object plane 22 in the depth direction compared to the reference lens, it can be seen that the change in position in the depth direction in the lens of Example 2 is smaller than that in the existing lens.

[0376] By adopting the progressive-power lens design method according to one embodiment of the present invention, it was found that the lens of Example 2 could align the vertical line of sight between the two eyes, as in the reference lens. Consequently, it was found that the discomfort felt by the wearer could be reduced.

[0377] (Example 3)

[0378] In the prescription information for producing the eyeglass lens pair, the spherical power S is 0.00 D [diopter], the addition power ADD is 2.50 D [diopter], the progressive zone length is 14 mm, and the refractive index is 1.60.

[0379] The distance reference point is set 8 mm vertically upward from the lens center 240 , and the near reference point is set 14 mm vertically downward from the lens center 240 and 2.5 mm horizontally toward the nose.

[0380] Figure 22 This is a graph showing the changes in the vertical surface prism difference in the lens of Example 3 and the conventional lens. The vertical axis represents the vertical surface prism difference [prism diopter / diopter], and the horizontal axis represents the x-coordinate [mm] at y = -14 mm. It should be noted that the above-mentioned Figure 20 Surface prism differentiation involving the "horizontal direction".

[0381] like Figure 22 As shown, in the case of the spectacle lens of Example 3, Figure 21The absolute value of the difference between the minimum difference value of one of the first and second areas and the maximum difference value of the other area is 0.2 [prism power / diopter] or more. On the other hand, in the case of conventional spectacle lenses, the absolute value of the difference between the minimum difference value and the maximum difference value is less than 0.2 [prism power / diopter].

[0382] Thus, the absolute value of the difference between the minimum and maximum differential values in the progressive-power lens of Example 3 is greater than that in conventional progressive-power lenses. This is because the lens surface shape is adjusted using the progressive-power lens design method according to one embodiment of the present invention. Specifically, this is because the difference in prismatic effect on the lines of sight of the left and right eyes is adjusted.

[0383] That is, in a pair of progressive-power lenses, the difference in prismatic effect between the area to the left of the origin (midpoint 306) of the right lens 300 and the area to the left of the origin (midpoint 406) of the left lens 400 at the same distance from the origin is increased compared with the existing pair of lenses. Similarly, the difference in prismatic effect between the area to the right of the origin (midpoint 306) of the right lens 300 and the area to the right of the origin (midpoint 406) of the left lens 400 at the same distance from the origin is increased compared with the existing pair of lenses.

[0384] Thus, by adjusting the difference in prismatic effect, it is possible to approach the difference in prismatic effect in a reference lens that does not cause discomfort. Therefore, by taking into account the difference in line of sight between the wearer's eyes, the discomfort caused by the difference in prismatic effect can be reduced.

[0385] In addition, according to each embodiment, it is preferable to find Figure 21 The positions of the difference value distribution regions 310 and 410 shown are where the addition value ADD reaches 85% to 100%. This region is particularly prone to image distortion and uncomfortable wearing caused by differences in the prism effect, so the effect of improving image distortion and uncomfortable wearing is greater.

[0386] Summary

[0387] The following summarizes the “progressive-power lens design method, manufacturing method, design system, and progressive-power lens” disclosed herein.

[0388] One embodiment of the present disclosure is as follows.

[0389] A method for designing a progressive-power lens, wherein the surface shape of the progressive-power lens is adjusted so that the difference V approaches the difference W.

[0390] The difference V is the difference between state A and state B when the progressive refractive power lens is worn, where state A is the state when the wearer visually sees an object at a limited distance in front of the wearer and at a position O on the wearer's median plane, and state B is the state when the wearer visually sees an object at a position P in a plane parallel to the front plane and containing the position O, at the same height in the vertical direction as the position O and located to the side of the position O in the horizontal direction.

[0391] The difference W is the difference between state C and state D when wearing a reference single-focus lens corresponding to a progressive refractive power lens or when viewed with the naked eye. State C is the state when visually viewing an object at position O, and state D is the state when visually viewing an object at position P.

[0392] Description of Reference Numerals

[0393] 10 Progressive power lenses

[0394] 10L left eye lens

[0395] 10R right eye lens

[0396] 10M integrated ophthalmic lenses

[0397] 12L left eye

[0398] 12R right eye

[0399] 12M Unifying Eye

[0400] 20 Target object surface seen (seen surface)

[0401] 22 Target object surface (actual surface)

[0402] 30L reference single-vision lens for right eye

[0403] 30R Reference single-vision lens for left eye

[0404] 30M integrated single-vision lenses

[0405] 50 systems

[0406] 52, 54 Optical store terminal

[0407] 56 Lens processing equipment

[0408] 60 Eyeglass Lens Pair Design Device

[0409] 62 CPU

[0410] 64 ROM

[0411] 66 RAM

[0412] 68 Ministry of Communications

[0413] 70 Input operation unit

[0414] 71 Display

[0415] 72 software modules

[0416] 72a Integrated Ophthalmic Lens Design Department

[0417] 72b Target object plane setting unit

[0418] 72c Lens Pair Design Department

[0419] 72d Reference Lens Design Department

[0420] 72e Line of Sight Calculation Department

[0421] 72f Judgment Department

[0422] 72g Surface shape adjustment unit

[0423] 72h Lens surface design department

[0424] 100 (existing) pairs of eyeglass lenses

[0425] 100L (existing) right eye lens

[0426] 100R (existing) left eye lens

[0427] 200 Main sight line

[0428] 210L (original design) left eye lens

[0429] 210R (original design) right eye lens

[0430] 220 Far Reference Point

[0431] 230, 308, 408 near reference points

[0432] 240 Center of eyeglass lens (prism measurement point)

[0433] 302, 304 hidden tags

[0434] 306, 406 midpoint

[0435] 310, 410 areas

Claims

1. A progressive-power lens comprising: a near portion having a refractive power for near vision; a distance portion having a refractive power for viewing objects farther away than near vision; and an intermediate portion having a progressive effect in which the refractive power gradually changes between the distance portion and the near portion; the progressive-power lens being characterized by: The lens has a prismatic effect adjustment area that makes the degree of image distortion caused by the unnecessary prismatic effect due to the progressive effect approach the degree of image distortion when wearing a reference single-focus lens corresponding to a progressive-power lens or when wearing the lens with the naked eye. In the prismatic effect adjustment area, the following conditions are met: Condition 1 In a plot with the horizontal direction of the lens as the horizontal axis and the surface prism difference in the vertical direction normalized by the addition as the vertical axis, the difference between the maximum and minimum values of the surface prism difference in the vertical direction at a predetermined portion α on a predetermined horizontal cross section in the near portion is 0.2 prism diopters / diopters or more, The position of the predetermined horizontal cross section is a position where the addition degree reaches 85% to 100%.

2. A progressive-power lens comprising: a near portion having a refractive power for near vision; a distance portion having a refractive power for viewing objects farther away than near vision; and an intermediate portion having a progressive effect in which the refractive power gradually changes between the distance portion and the near portion; the progressive-power lens being characterized by: The lens has a prismatic effect adjustment area that makes the degree of image distortion caused by the unnecessary prismatic effect due to the progressive effect approach the degree of image distortion when wearing a reference single-focus lens corresponding to a progressive-power lens or when wearing the lens with the naked eye. In the prismatic effect adjustment area, the following conditions are met: Condition 2 In a plot with the horizontal direction of the lens as the horizontal axis and the surface prism difference in the horizontal direction normalized by the addition as the vertical axis, at position x=0 within a predetermined portion γ on a predetermined horizontal cross-section in the near portion, the absolute value of the surface prism difference in the horizontal direction is 0.25 prism diopters / diopters or greater, and the position x=0 within the predetermined portion γ is located directly below the prism reference point or directly below the midpoint of two alignment fiducial marks of the progressive power lens. The position of the predetermined horizontal cross section is a position where the addition degree reaches 85% to 100%.

3. A progressive-power lens comprising: a near portion having a refractive power for near vision; a distance portion having a refractive power for viewing objects farther away than near vision; and an intermediate portion having a progressive effect in which the refractive power gradually changes between the distance portion and the near portion; the progressive-power lens being characterized by: The lens has a prismatic effect adjustment area that makes the degree of image distortion caused by the unnecessary prismatic effect due to the progressive effect approach the degree of image distortion when wearing a reference single-focus lens corresponding to a progressive-power lens or when wearing the lens with the naked eye. In the prismatic effect adjustment area, the following two conditions are met: Condition 1 In a plot with the horizontal direction of the lens as the horizontal axis and the surface prism difference in the vertical direction normalized by the addition as the vertical axis, the difference between the maximum and minimum values of the surface prism difference in the vertical direction at a predetermined portion α on a predetermined horizontal cross section in the near portion is 0.2 prism diopters / diopters or more, Condition 2 In a plot with the horizontal direction of the lens as the horizontal axis and the surface prism difference in the horizontal direction normalized by the addition as the vertical axis, at position x=0 within a predetermined portion γ on a predetermined horizontal cross-section in the near portion, the absolute value of the surface prism difference in the horizontal direction is 0.25 prism diopters / diopters or greater, and the position x=0 within the predetermined portion γ is located directly below the prism reference point or directly below the midpoint of two alignment fiducial marks of the progressive power lens. The position of the predetermined horizontal cross section is a position where the addition degree reaches 85% to 100%.

4. The progressive-power lens according to any one of claims 1 to 3, wherein: The following conditions are also met: Condition three The plot of the progressive-addition lens with the line of sight as the horizontal axis and the depth position information as the vertical axis does not intersect with the plot of the reference single-focal lens corresponding to the progressive-addition lens when worn or when viewed with the naked eye.

5. The progressive-power lens according to any one of claims 1 to 3, wherein: The prismatic action adjustment region includes a region on the side that is offset from the main viewing line in the horizontal direction.

Images