Progressive power lens and method of designing the same

Abstract

Techniques are provided to improve the wearing sensation when looking with both eyes. A pair of progressive power lenses and techniques associated therewith are provided in which, in the power distribution in the horizontal section of the right-eye lens, there is a peak at a position away from the main gaze line, and in the power distribution in the horizontal section of the left-eye lens, there is a peak at a position away from the main gaze line in the opposite direction to the case of the right-eye lens.

Description

Technical Field

[0001] The invention relates to a pair of progressive-power lenses and a design method thereof. Background Art

[0002] In Patent Document 1, when using the near area to view a nearby object with both eyes, in order to ensure comfortable viewing regardless of the left-right position of the object, compared with the conventional design example, a positive power is added to the right side (ear side) of the near power measurement point NP (referred to as the near power measurement point in this specification), and a negative power is added to the left side (nose side) of the near power measurement point NP (

[0027] , Figure 2 ,summary).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-203705 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] If the patent document 1 Figure 2 , to the right of the near power measurement point (toward the ear), a higher power than the near power (i.e., spherical power + additive power) is achieved. If the intentional addition of power leads to a power error, the wearer may experience blurry and distorted images, which may reduce the wearing experience.

[0008] An object of one embodiment of the present invention is to provide a technology that improves the wearing comfort when viewing with both eyes.

[0009] Means for solving problems

[0010] A first embodiment of the present invention is a pair of progressive-power lenses, comprising a right-eye lens and a left-eye lens as progressive-power lenses, wherein a portion on the right-eye lens and a portion on the left-eye lens through which the line of sight passes when viewing an object present on the wearer's median plane and at a predetermined distance from the wearer in frontal view are defined as a principal gaze line, and a power distribution on a horizontal cross section of the right-eye lens has a peak at a position away from the principal gaze line, and a power distribution on a horizontal cross section of the left-eye lens has a peak at a position away from the principal gaze line in a direction opposite to that of the right-eye lens.

[0011] The second embodiment of the present invention is the embodiment described in the first embodiment, wherein the distance between the peak position of the diopter distribution at the horizontal cross section of the right-eye lens and the main gaze line is equal to the distance between the peak position of the diopter distribution at the horizontal cross section of the left-eye lens and the main gaze line.

[0012] The third embodiment of the present invention is the embodiment described in the first or second embodiment, wherein the degree of distance between the position of the peak of the diopter distribution at the horizontal cross-section of the lens for the right eye and the main gaze line and the degree of distance between the position of the peak of the diopter distribution at the horizontal cross-section of the lens for the left eye and the main gaze line are both greater than 0 degrees and less than 5 degrees when expressed as the difference in the rotation angle of the eyeball when the line of sight is moved horizontally from the main gaze line.

[0013] The fourth embodiment of the present invention is a embodiment described in any one of the first to third embodiments, wherein the position of the peak of the power distribution in the lens for the right eye is the position at which the eyeball rotates to the left from the main gaze line when viewed from the wearer, and the position of the peak of the power distribution in the lens for the left eye is the position at which the eyeball rotates to the right from the main gaze line when viewed from the wearer.

[0014] The fifth aspect of the present invention is the aspect described in any one of the first to fourth aspects, wherein the peak at a position away from the main gaze line in the power distribution is at least between the distance power measurement point and the near power measurement point.

[0015] A sixth aspect of the present invention is the aspect described in any one of the first to fifth aspects, wherein the portion having a peak at a position away from the main gaze line in the power distribution is at least the near portion.

[0016] The seventh scheme of the present invention is a scheme recorded in any one of the first to sixth schemes, wherein, when the object being viewed is represented by the eye rotation angle difference with the line of sight moving in the right direction relative to the median plane being set to positive and the line of sight moving in the left direction being set to negative, as seen from the wearer, in the horizontal cross-section of each lens area including at least a part of the main gaze line, the eye rotation angle difference of the object in front of the line of sight passing through the peak position of the additional power distribution in the power distribution of the prescription power of the right eye achieved by the right eye lens and the eye rotation angle difference of the object in front of the line of sight passing through the peak position of the additional power distribution in the power distribution of the prescription power of the left eye achieved by the left eye lens have different signs from each other.

[0017] The eighth embodiment of the present invention is a method for designing a pair of progressive-power lenses, which is a method for designing a pair of eyeglass lenses consisting of a right-eye lens and a left-eye lens as progressive-power lenses, wherein, when the portion on the right-eye lens and the portion on the left-eye lens through which the line of sight passes when viewing an object existing on the wearer's median plane and at a predetermined distance from the wearer from the front are set as the main gaze line, in the power distribution at the horizontal cross-section of the right-eye lens, a peak is arranged at a position away from the main gaze line, and in the power distribution at the horizontal cross-section of the left-eye lens, a peak is arranged at a position away from the main gaze line in the direction opposite to that of the right-eye lens.

[0018] The ninth aspect of the present invention is the aspect described in the eighth aspect, which comprises:

[0019] a binocular visual field coordinate acquisition step of acquiring, in a horizontal cross section of an area including at least a portion of the principal gaze line, a right eye diopter distribution converted into binocular visual field coordinates to achieve a prescription diopter for the right eye using a right eye lens, and a left eye diopter distribution converted into binocular visual field coordinates to achieve a prescription diopter for the left eye using a left eye lens;

[0020] a power distribution shifting step in which the power distribution for the right eye is shifted in one direction and the power distribution for the left eye is shifted in a direction opposite to the direction in which the power distribution for the right eye is shifted;

[0021] a simulation step in which the shift amount of the left eye power distribution is set by a predetermined value and the shift amount of the right eye power distribution is set by a predetermined value, and simulation is performed; and

[0022] The determination step is to determine whether the simulation result satisfies a predetermined condition.

[0023] The tenth embodiment of the present invention is the embodiment described in the eighth or ninth embodiment, wherein, when the object viewed from the wearer's perspective is represented by an eye rotation angle difference in which the line of sight movement in the right direction relative to the median plane is set to positive and the line of sight movement in the left direction is set to negative, in the horizontal cross-section of each lens area including at least a portion of the main gaze line, the eye rotation angle difference of the object in front of the line of sight passing through the peak position of the additional power distribution in the power distribution of the prescription power of the right eye achieved with the right eye lens and the eye rotation angle difference of the object in front of the line of sight passing through the peak position of the additional power distribution in the power distribution of the prescription power of the left eye achieved with the left eye lens have different signs from each other.

[0024] Other aspects of the present invention that can be combined with the above aspects are as follows.

[0025] A method for designing a pair of progressive-power lenses, wherein the distance between the peak of the power distribution in a horizontal cross section of the right-eye lens and the main gaze line is equal to the distance between the peak of the power distribution in a horizontal cross section of the left-eye lens and the main gaze line.

[0026] A method for designing a pair of progressive-power lenses, wherein the distance between the peak of the power distribution at a horizontal cross-section of the lens for right eye and the principal gaze line and the distance between the peak of the power distribution at a horizontal cross-section of the lens for left eye and the principal gaze line are both greater than 0 degrees and less than 5 degrees, when expressed as the difference in the gyration angle of the eyeball when the line of sight is shifted horizontally from the principal gaze line.

[0027] A method for designing a pair of progressive-power lenses, wherein the peak of the power distribution in the lens for the right eye is located at a position where the eyeball rotates to the left from the main gaze line as viewed by the wearer, and the peak of the power distribution in the lens for the left eye is located at a position where the eyeball rotates to the right from the main gaze line as viewed by the wearer.

[0028] A method for designing a pair of progressive-power lenses, wherein the area containing at least a portion of the principal gaze line includes at least the near portion.

[0029] A method for designing a pair of progressive power lenses, wherein a region including at least a portion of the principal gaze line is located between a distance power measurement point and a near power measurement point.

[0030] The maximum intensity of the two peaks (Y coordinates of the peak positions) is below the nearly used intensity.

[0031] The absolute value of the difference in the swirl angle at the peak positions of the left and right frequency distributions (the difference between the two distances) may not be strictly equal, and a difference of, for example, 1 degree or 2 degrees or less may be acceptable.

[0032] The degree of distance between the peak position of the diopter distribution at the horizontal cross-section of the lens for the right eye and the main gaze line and the degree of distance between the peak position of the diopter distribution at the horizontal cross-section of the lens for the left eye and the main gaze line are expressed as the difference in the rotation angle of the eyeball when the line of sight is moved horizontally from the main gaze line. There is no lower limit, for example, 3 degrees can be listed.

[0033] The preparation step preferably includes the following. In the preparation step, the power distribution of the two lenses is designed using the same conventional techniques. Of course, at this point, the wearer's order information (prescription power, pupillary distance (PD), etc.) is input into the system (input step), design parameters are calculated (design parameter calculation step), and the power distribution of the two lenses is designed based on these design parameters (power distribution design step). Examples of design parameters include power distribution and aberration distribution.

[0034] In the degree transfer step, it is preferable to move the drawing in the X direction without moving it in the Y direction.

[0035] Preferably, the offset of each drawing is set to a specified value, and a simulation is performed (simulation step). Then, it is preferably determined whether the result satisfies specified conditions (e.g., the allowable amount of diametrical error, accommodative force, contrast, sensitivity, etc.) (determination step). If so, the design is terminated. If not, the offset of each drawing is preferably changed, other contents are modified, and the design parameters are calculated again. Furthermore, this process is preferably repeated until the simulation result satisfies the specified conditions.

[0036] A pair of progressive-power lenses and related technologies in one embodiment of the present invention preferably have the following provisions.

[0037] "Pair of progressive power lenses and associated technique, wherein the following (1) (2) evaluation conditions are satisfied and the monocular maximum power position difference d is within the range of ±3 degrees (preferably ±2 degrees, more preferably ±1.5 degrees) of the value of the (3) wide vision characteristic.

[0038] (1) (Monocular maximum power MP - Binocular front view average power BP) ≦ 0.25D

[0039] (2) (Binocular front view average power BP - Add power) > 0D

[0040] (3) The field of view W (wide vision characteristic) from the add power only decreases by 0.50D (preferably 0.25D) at the value"

[0041] Further, as a system of a design method of a pair of progressive power lenses as one aspect of the present application or a program for implementing the design method, the technical idea of the present application is also reflected in the program for causing a computer to function.

[0042] The system is configured as described below.

[0043] "A design system for a pair of progressive power lenses, which is a design system for a pair of progressive power lenses composed of a right-eye lens and a left-eye lens as progressive power lenses, wherein, when the positions on the right-eye lens and the positions on the left-eye lens through which the line of sight passes when a front view of an object that is visually recognized to exist on the front surface of the wearer at a prescribed distance from the wearer is set as a primary gaze line, in the power distribution at the horizontal cross section of the right-eye lens, a peak is arranged at a position away from the primary gaze line, and in the power distribution at the horizontal cross section of the left-eye lens, a peak is arranged at a position away from the primary gaze line in the opposite direction to the case of the right-eye lens."

[0044] The program is configured as described below.

[0045] "A design program for a pair of progressive power lenses, which is a design system for a pair of progressive power lenses composed of a right-eye lens and a left-eye lens as progressive power lenses, wherein, when the positions on the right-eye lens and the positions on the left-eye lens through which the line of sight passes when a front view of an object that is visually recognized to exist on the front surface of the wearer at a prescribed distance from the wearer is set as a primary gaze line, in the power distribution at the horizontal cross section of the right-eye lens, a peak is arranged at a position away from the primary gaze line, and in the power distribution at the horizontal cross section of the left-eye lens, a peak is arranged at a position away from the primary gaze line in the opposite direction to the case of the right-eye lens, and causes a computer to function."

[0046] Effects of the Invention

[0047] According to one embodiment of the present invention, it is possible to provide a technology that improves the wearing comfort when viewing with both eyes. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a schematic diagram for explaining progressive-power lenses.

[0049] Figure 2 The flowchart is used to illustrate a method for designing a pair of progressive-power lenses according to one embodiment of the present invention.

[0050] Figure 3 This is a graph showing the diopter distribution R1 for the right eye, the diopter distribution L1 for the left eye, and the average value PW1 of both diopter distributions before the drawing is transitioned (equivalent to Comparative Example 1).

[0051] Figure 4 This is a graph showing the power distribution R2 for the right eye, the power distribution L2 for the left eye, and the average value PW2 of the two power distributions after the mapping is shifted (equivalent to Example 1).

[0052] Figure 5 This is a coordinate diagram related to Example 1 and Comparative Example 1, where the X-axis is the eyeball rotation angle difference and the Y-axis is the self-adjustment amount.

[0053] Figure 6 This is a graph showing the diopter distribution for the right eye and the diopter distribution for the left eye after the plot is shifted and before the additional diopter distribution is converted and extracted.

[0054] Figure 7 To express as a composition Figure 6 A graph showing the right eye power distribution R1, the left eye power distribution L1, and the average value PW1 of the two power distributions before the plot is shifted, which is an additional power distribution of a part of the power distribution (equivalent to Comparative Example 2).

[0055] Figure 8 To express as a composition Figure 6 A coordinate diagram of the right eye power distribution R2, the left eye power distribution L2, and the average value PW2 of the two power distributions after the drawing is migrated, which is an additional power distribution of a part of the power distribution (equivalent to Example 2).

[0056] Figure 9 This is a coordinate diagram related to Example 2 and Comparative Example 2, where the X-axis is the eyeball rotation angle difference [unit: degree] and the Y-axis is the self-adjustment amount [unit: D].

[0057] Figure 10 will be for Figure 4The additional power extracted by transformation is expressed as a power distribution, which is an explanatory diagram used to show the corresponding parts of the maximum power of monocular MP, the average power of binocular frontal vision BP, the visual field width W at the threshold, and the maximum power position difference d of monocular.

[0058] Figure 11 This is a coordinate diagram of Example 3 when the X-axis is set to the maximum diopter position difference d [degrees] of a single eye, the central Y-axis involved in evaluation conditions (1) and (2) is set to the diopter difference [D], and the right Y-axis involved in evaluation condition (3) is set to the field of view width [degrees] at the threshold. DETAILED DESCRIPTION

[0059] The following description will describe embodiments of the present invention. The following description based on the drawings is for illustrative purposes only, and the present invention is not limited to the illustrative embodiments.

[0060] Figure 1 This is a schematic diagram for explaining progressive-power lenses.

[0061] <Definition>

[0062] A progressive-addition lens according to one embodiment of the present invention has an object-side surface and an eyeball-side surface. The "object-side surface" refers to the surface facing the object side when the eyeglasses including the progressive-addition lens are worn by the wearer, while the "eyeball-side surface" refers to the opposite surface, that is, the surface facing the eyeball side when the eyeglasses including the progressive-addition lens are worn by the wearer.

[0063] In one embodiment of the present invention, both the right-eye lens and the left-eye lens are progressive-power lenses. These two progressive-power lenses are also collectively referred to as two lenses or a pair of progressive-power lenses.

[0064] A progressive-power lens comprises a distance portion provided on the upper portion of the lens and having a refractive power for farsightedness, a near portion provided on the lower portion of the lens and having a refractive power for nearsightedness, and an intermediate portion provided between the distance portion and the near portion, the refractive power slowly changing between the distance portion and the near portion.

[0065] The term "distance portion" is not particularly limited as long as it is used for viewing distances farther than the near distance. For example, it can be a region not for infinity but for viewing a predetermined distance (approximately 1 meter). Examples of spectacle lenses that include such a region include intermediate-near lenses corresponding to object distances ranging from intermediate distances (1 meter to 40 cm) to near distances (40 cm to 10 cm), and near-near lenses corresponding to distances within this range.

[0066] The principal gaze line in one embodiment of the present invention, as the name suggests, refers to the line formed by the portion of the progressive-power lens through which the wearer's line of sight converges when the wearer shifts their gaze from the celestial direction (hereinafter referred to as "upward") to the terrestrial direction (hereinafter referred to as "downward") while wearing progressive-power lenses. This principal gaze line forms the basis for the design of progressive-power lenses.

[0067] In one embodiment of the present invention, the portion on each progressive-power lens through which the wearer's line of sight passes when viewing an object located on the wearer's median plane and at a predetermined distance from the wearer while wearing a pair of progressive-power lenses is defined as the principal fixation line. In one embodiment of the present invention, a gyration angle difference (horizontal gyration angle difference) from the frontal view state is also defined.

[0068] Furthermore, one aspect of the present invention is characterized in that the peak positions of the power distributions in the horizontal cross-sections of the right-eye lens and the left-eye lens are horizontally offset in opposite directions, and the shape of the principal gaze line (either straight or curved) is not limited. Considering that the shape of the principal gaze line may vary depending on the wearer, the progressive-power lens constituting one aspect of the present invention does not necessarily have to uniformly define the shape and position of the principal gaze line itself (e.g., using fixed coordinate values). The principal gaze line can be determined by identifying the wearer, having the wearer actually wear a pair of progressive-power lenses, and determining the portion of the lens through which it passes when viewed from the front.

[0069] Regarding the eye's rotation angle (in other words, visual angle), the range from the lens center (optical center OC or geometric center GC) to a radius of 4.5 mm to 25 mm roughly corresponds to a rotation angle of 10 degrees or more and 45 degrees or less. The relationship between the eye's rotation angle and its corresponding position on the spectacle lens is described in, for example, Japanese Patent No. 2131365 and Japanese Patent Application Laid-Open No. 2016-26324, and therefore, a detailed description thereof will be omitted.

[0070] The distance power measurement point is the point at which the spherical and cylindrical refractive powers specified in the wearer's prescription data are applied to a progressive-power lens. The spherical refractive power refers to the so-called spherical power S, and the cylindrical refractive power refers to the so-called astigmatism C. The distance power measurement point (hereinafter referred to simply as measurement point F or point F) is, for example, located 8.0 mm from a horizontal line connecting the positions of the two hidden marks M1 and M2 on the distance portion of the lens, on the meridian (a vertical line passing through the center of the lens (specifically, a vertical line passing between the two hidden marks M1 and M2)).

[0071] The fitting point or eye point (EP) is the position where the line of sight passes when looking straight ahead while wearing progressive power lenses. It is usually located a few mm below the measuring point F. Figure 1In the figure, the geometric center GC and the optical center OC are set at the midpoint of the hidden marks M1 and M2, and EP is set above them. In addition, the prism reference point is consistent with OC.

[0072] The near power measurement point is the point where the add-on power ADD is added to the spherical refractive power specified in the wearer's prescription data. This refers to the point where the spherical refractive power + ADD is initially achieved when looking downward from the top of the lens. The near power measurement point (hereinafter referred to as measurement point N or point N) is also located on the principal fixation line. Furthermore, refractive power changes generally begin below measurement point F and end above measurement point N. For progressive addition lenses for near and far vision, refractive power changes often begin at EP.

[0073] The positions of the measurement point F, the fitting point, the eye point EP, and the measurement point N can be determined by referring to a remark chart or a centration chart issued by the lens manufacturer.

[0074] Furthermore, the horizontal direction coincides with the direction of a horizontal reference line connecting two alignment reference marks (so-called hidden marks M1 and M2) used for frame installation. This horizontal reference line extends horizontally between the upper and lower vertices of a progressive-power lens (a round lens before frame installation). Furthermore, in one embodiment of the present invention, an example is described in which the hidden marks M1 and M2 are arranged so that the main gaze line passes through the center of the horizontal reference line connecting the two hidden marks M1 and M2.

[0075] Incidentally, the wearer's prescription data is stored in the lens case of the progressive-addition lens. In other words, the presence of the lens case allows identification of the progressive-addition lens as an item based on the wearer's prescription data. Furthermore, progressive-addition lenses are typically paired with the lens case. Therefore, the progressive-addition lens included with the lens case also reflects the technical concept of the present invention, and the same applies to the combination of the lens case and progressive-addition lens.

[0076]

[0077] One embodiment of the present invention is as follows.

[0078] “A pair of progressive-power lenses comprising a right-eye lens and a left-eye lens as progressive-power lenses, wherein, when a portion on the right-eye lens and a portion on the left-eye lens through which the line of sight passes when viewing an object present on the wearer's median plane and at a predetermined distance from the wearer in frontal view is defined as a principal gaze line, the power distribution of a horizontal cross section of the right-eye lens has a peak at a position away from the principal gaze line, and the power distribution of a horizontal cross section of the left-eye lens has a peak at a position away from the principal gaze line in a direction opposite to that of the right-eye lens.”

[0079] When the above configuration is expressed using XY coordinates, it is as follows.

[0080] “A pair of progressive-power lenses, wherein, with the difference in eye rotation angle when the line of sight is shifted horizontally from the principal gaze line as the X-axis (positive when the eye rotates to the right from the principal gaze line, and negative when the eye rotates to the left from the principal gaze line, as viewed from the wearer), and the power as the Y-axis, the X-coordinate of the peak of the power distribution of the prescription power for the right eye achieved by the right-eye lens and the X-coordinate of the peak of the power distribution of the prescription power for the left eye achieved by the left-eye lens are shifted from X=0 in a horizontal cross-section of an area including at least a portion of the principal gaze line, such that the shift directions of the two X-coordinates on the X-axis are opposite to each other.”

[0081] In one embodiment of the present invention, a measurement point F, a fitting point or eye point EP, a measurement point N, and two hidden marks M1 and M2 are provided on both the right-eye lens and the left-eye lens.

[0082] A region encompassing at least a portion of the principal gaze line is selected. This region is the region of the progressive-power lens when viewed from the object side and can be a linear region or a planar region. When a planar region is selected, the plot of the horizontal cross-section described in the following paragraphs satisfies the following conditions 1 and 2 at any position within the planar region (i.e., the entire planar region).

[0083] In a drawing in which the rotation angle of the eyeball in the horizontal direction from the main gaze line is set as the X-axis (a positive sign is given when the eyeball is rotated to the right from the wearer's perspective, and a negative sign is given when the eyeball is rotated to the left from the wearer's perspective) and the degree is set as the Y-axis, the following conditions are satisfied.

[0084] (Condition 1) In a horizontal cross-section of an area including at least a portion of the principal gaze line, the X coordinate of the peak of the power distribution of the prescription power achieved by the right-eye lens and the X coordinate of the peak of the power distribution of the prescription power achieved by the left-eye lens are shifted from X=0.

[0085] (Condition 2) The offset directions of the two X coordinates on the X axis are opposite to each other.

[0086] In one embodiment of the present invention, a power distribution of the prescription power for the right eye is achieved that excludes irregular increases or decreases in power caused by peripheral deformation associated with the manufacture of progressive-power lenses.

[0087] By simultaneously satisfying the above conditions 1 and 2, there is no error in the power level that occurs with intentional power addition. As a result, the wearing comfort when viewing with both eyes is improved.

[0088] <Details of a pair of progressive-power lenses (preferred example, modified example)>

[0089] The technical scope of the present invention is not limited to the above-described embodiment, and includes various changes and improvements within the scope of producing specific effects obtained by the technical features of the invention and their combination.

[0090] The absolute value of the X-coordinate of the peak of the diopter distribution in the right-eye lens is preferably equal to the absolute value of the X-coordinate of the peak of the diopter distribution in the left-eye lens (Preferred Example 1). Even if the peak of the diopter distribution is shifted in the X direction from X=0, the wearing comfort when viewing with both eyes is improved if the amount of shift between the right-eye lens and the left-eye lens does not differ excessively. Furthermore, the two absolute values ​​do not need to be strictly equal; for example, a difference of 1 or 2 degrees or less is acceptable.

[0091] The above-mentioned preferred embodiment 1 can be expressed as follows: "The distance between the peak position of the diopter distribution on the horizontal cross section of the right-eye lens and the main gaze line is equal to the distance between the peak position of the diopter distribution on the horizontal cross section of the left-eye lens and the main gaze line."

[0092] Preferably, the absolute value of the X coordinate of the peak of the diopter distribution in the right-eye lens and the absolute value of the X coordinate of the peak of the diopter distribution in the left-eye lens are both greater than 0 degrees and less than 5 degrees (0 < |X| ≦ 5 degrees) (Preferred Example 2). When the peak position of the diopter distribution does not deviate excessively from the principal line of sight, the diopter on the principal line of sight can be appropriately maintained, and objects at a predetermined distance can be comfortably recognized when viewing the subject with both eyes straight ahead.

[0093] The above-mentioned preferred embodiment 2 can be expressed as follows.

[0094] "The distance between the peak position of the diopter distribution on the horizontal cross section of the right-eye lens and the principal gaze line, and the distance between the peak position of the diopter distribution on the horizontal cross section of the left-eye lens and the principal gaze line, expressed as the difference in the gyration angle of the eyeball when the line of sight is shifted horizontally from the principal gaze line, are both greater than 0 degrees and less than 5 degrees."

[0095] The sign of the X-coordinate of the peak of the diopter distribution in the right-eye lens is preferably negative, while the sign of the X-coordinate of the peak of the diopter distribution in the left-eye lens is preferably positive (Preferred Example 3). As will be shown in the examples described below, with this configuration, when the wearer views an object at a predetermined distance with both eyes, the amount of accommodation used by the wearer's eyes can be reduced primarily to the sides. This has the effect of reducing wearer fatigue.

[0096] Naturally, there are concerns about a decrease in diopter power along the primary line of sight compared to conventional devices. However, testing of the following examples has shown that, with one embodiment of the present invention, the wearer's comfort level is improved, and a decrease in diopter power along the primary line of sight is not recognized as a problem. On the contrary, the advantages of a wider field of view and reduced fatigue for the wearer outweigh these concerns.

[0097] The above-mentioned preferred embodiment 3 can be expressed as follows.

[0098] "The peak position of the diopter distribution in the right-eye lens is the position where the eyeball rotates to the left from the main gaze line as seen by the wearer. The peak position of the diopter distribution in the left-eye lens is the position where the eyeball rotates to the right from the main gaze line as seen by the wearer."

[0099] The region in the horizontal cross section where the above-mentioned plot is obtained is preferably defined as the region between measurement point F and measurement point N, including at least a portion of the principal gaze line. Furthermore, the above-mentioned conditions can be satisfied in the above-mentioned plot in regions outside of this region. On the other hand, the wearer's line of sight rarely passes through the region above measurement point F on the principal gaze line, so even if the above-mentioned conditions are not satisfied, the effects of the present invention can be achieved. The same applies to the region below measurement point N.

[0100] The area including at least a portion of the principal visual line is not limited, as long as the above conditions are satisfied in an area on the lens that matches the visual distance when the wearer frequently performs tasks, that is, the working distance.

[0101] However, the area encompassing at least a portion of the principal line of sight preferably includes at least the near portion (particularly the measurement point N). Near vision has a higher power than distance vision, making it more susceptible to power errors. Therefore, applying one aspect of the present invention to the near portion significantly enhances its effectiveness. Furthermore, the aforementioned conditions can be satisfied in the aforementioned plot at a horizontal cross-section of the linear area encompassing the measurement point N.

[0102] Furthermore, the presence of a region with a peak on the main fixation line is not excluded from the present invention. For example, the presence of a peak on the main fixation line in a horizontal cross section of a region that includes at least a portion of the main fixation line and corresponds to a predetermined object distance between the far vision distance and the near vision distance is not excluded from the present invention.

[0103] However, the technical concept of the present invention is to actively distance the peak of the diopter distribution from the main fixation line in the opposite direction when viewing with both eyes. This allows for diopter levels that would not have a peak in the frontal view direction, while also widening the peak width of the diopter distribution when viewing with both eyes. Therefore, even if a peak exists in an area on the main fixation line, it is preferable that the majority of the area between measurement point F and measurement point N (for example, at least 50% of the area between measurement point F and measurement point N when viewing in the vertical direction, preferably at least 70%) does not have a peak on the main fixation line.

[0104] The Y coordinate of the peak of the power distribution for the right-eye lens can be different from the Y coordinate of the peak of the power distribution for the left-eye lens. These Y coordinate values ​​correspond to the prescription power of the right-eye lens (distance power + add-on power, i.e., near power) and the prescription power of the left-eye lens (distance power + add-on power, i.e., near power). If the prescription power of the two eyes is different, the values ​​of the two Y coordinates will naturally be different. This situation is called diopter.

[0105] The Y coordinates of the two peaks can be set to be below the near diopter. For example, in the progressive-power lens according to one embodiment of the present invention, there are cases where no purposeful addition of diopter is performed. That is, the diopter distribution can be shifted in the X direction without shifting in the Y direction. In this case, the Y coordinates of the two peaks remain at the near diopter. In this case, the Y coordinates of the plotted portion outside the peaks will naturally be below the near diopter.

[0106] When this configuration is adopted, unlike Patent Document 1, there is no power error caused by intentional power addition, and the wearer is less likely to feel blur or distortion of the image, leading to a further improvement in the wearing comfort.

[0107] On the other hand, the present invention does not prevent the Y coordinates of the two peaks from exceeding the near power. Even in this case, by making the sign of the power distribution peaks in the right-eye lens and the left-eye lens opposite (specifically, making the X coordinate of the peak negative in the right-eye lens and positive in the left-eye lens), the wearing comfort when using both eyes can be improved compared to the invention described in Patent Document 2.

[0108] <Design Method for a Pair of Progressive-Power Lenses>

[0109] The following describes a method for designing a pair of progressive-power lenses according to one embodiment of the present invention. The details that overlap with those in the above-mentioned "Pair of Progressive-Power Lenses" are omitted.

[0110] A method for designing a pair of progressive-power lenses according to one embodiment of the present invention is configured as follows.

[0111] “A method for designing a pair of progressive-power lenses, comprising a right-eye lens and a left-eye lens as progressive-power lenses, wherein, when a portion on the right-eye lens and a portion on the left-eye lens through which the line of sight passes when viewing an object located on the wearer's median plane and at a predetermined distance from the wearer in frontal view are defined as the principal gaze line, a peak is arranged in the diopter distribution of a horizontal cross section of the right-eye lens at a position away from the principal gaze line, and a peak is arranged in the diopter distribution of a horizontal cross section of the left-eye lens at a position away from the principal gaze line in a direction opposite to that of the right-eye lens.”

[0112] When the above configuration is expressed using XY coordinates, it is as follows.

[0113] "A method for designing a pair of progressive-power lenses, wherein the difference in eye rotation angle when the line of sight is shifted horizontally from the principal gaze line is defined as the X-axis (positive when the eye rotates to the right from the principal gaze line, and negative when the eye rotates to the left from the principal gaze line, as viewed from the wearer), and the power is defined as the Y-axis. In a horizontal cross-section of an area between a distance power measurement point and a near power measurement point, including at least a portion of the principal gaze line, the X coordinates of the peak of the power distribution for the prescription power achieved by the right eye lens and the peak of the power distribution for the prescription power achieved by the left eye lens are shifted from X=0, with the shift directions of the two X coordinates on the X-axis being opposite to each other, and the Y coordinates of the two peaks are set to be less than the near power."

[0114] In the preparation process, the power distribution of the two lenses is designed using the same methods as in the past. Of course, at this point, the wearer's order information (prescription power, pupillary distance PD, etc.) is input into the system (using the input process of the input unit), design parameters are calculated (using the design parameter calculation process of the design parameter calculation unit), and the power distribution of the two lenses is designed based on these design parameters (using the power distribution design process of the power distribution design unit). Examples of design parameters include power distribution and aberration distribution. These can be designed using the same methods as in the past, so a detailed description is omitted.

[0115] In one embodiment of the present invention, the above-mentioned drawing at the horizontal cross section of the area including at least a part of the main gaze line is obtained from the above-mentioned design content. The drawing can be obtained using a well-known ray tracing technique. The X-axis of the drawing is also called the binocular visual field coordinate. Therefore, the process of obtaining the above-mentioned drawing is also called the binocular visual field coordinate acquisition process using the binocular visual field coordinate acquisition unit. Then, the drawing (preferably, not offset in the Y direction) is offset in the X direction (using the power distribution migration process of the power distribution migration unit). At this time, the direction of moving the drawing of the lens for the right eye is opposite to the direction of moving the drawing of the lens for the left eye. This is the power distribution migration process. In addition, the preferred examples and modifications related to this offset are, for example, as described in the above-mentioned <Details of a pair of progressive refractive power lenses (preferred examples, modifications)>.

[0116] The offset values ​​for each drawing are set to specified values, and a simulation is performed (using the simulation step of the simulation unit). The results are then determined to see if they meet specified conditions (e.g., tolerance for diametrical error, accommodative force, contrast, sensitivity, etc.) (using the determination step of the determination unit). If so, the design is terminated. If not, the offset values ​​for each drawing are changed, other parameters are modified, and the design parameters are calculated again. This process is repeated until the simulation results meet the specified conditions.

[0117] It is preferable that the absolute value of the amount by which the diopter distribution for the right eye is shifted is equal to the absolute value of the amount by which the diopter distribution for the left eye is shifted.

[0118] It is preferable that both the absolute value of the amount by which the diopter distribution of the right eye is shifted and the absolute value of the amount by which the diopter distribution of the left eye is shifted be greater than 0 degrees and less than 5 degrees.

[0119] It is preferable that the direction of shift of the diopter distribution for the right eye is the negative direction of the X-axis, and the direction of shift of the diopter distribution for the left eye is the positive direction of the X-axis.

[0120] It is preferred that the region including at least a portion of the main visual line includes at least the near part.

[0121] Furthermore, the system for realizing a method for designing a pair of progressive-power lenses, which is one aspect of the present invention, or a program for realizing the design method also reflects the technical idea of ​​the present invention in a program for causing a computer to function.

[0122] The system is composed as follows.

[0123] “A design system for a pair of progressive-power lenses, comprising a right-eye lens and a left-eye lens as progressive-power lenses, wherein, when a portion on the right-eye lens and a portion on the left-eye lens through which the line of sight passes when viewing an object located on the wearer's median plane and at a predetermined distance from the wearer in frontal view are defined as the principal gaze line, a power distribution on a horizontal cross section of the right-eye lens has a peak located at a position away from the principal gaze line, and a power distribution on a horizontal cross section of the left-eye lens has a peak located at a position away from the principal gaze line in a direction opposite to that of the right-eye lens.”

[0124] The program is structured as follows.

[0125] "A program for designing a pair of progressive-power lenses, comprising a right-eye lens and a left-eye lens as progressive-power lenses, wherein, when the portion on the right-eye lens and the portion on the left-eye lens through which the line of sight passes when viewing an object located on the wearer's median plane at a predetermined distance from the wearer in frontal view are defined as the principal gaze line, a computer is configured to arrange a peak in the power distribution of a horizontal cross section of the right-eye lens at a position away from the principal gaze line, and arrange a peak in the power distribution of a horizontal cross section of the left-eye lens at a position away from the principal gaze line in a direction opposite to that of the right-eye lens, and to operate a computer."

[0126] Example

[0127] Next, the present invention will be described in detail with reference to the following examples. However, the present invention is not limited to the following examples.

[0128] [Example 1]

[0129] Wearer A was given spectacle lenses with a spherical power S of 0.00D, an astigmatism C of 0.00D, and an added power ADD of 2.00D. The wearer's monocular interpupillary distance was set to 32mm. The wearer's frequent near work distance was 50cm. Specifically, the distance to the object viewed from the front when the above-mentioned plot (binocular visual field coordinates) was obtained was set to 50cm.

[0130] In addition, a vertical plane object plane is set as a visual recognition target. The vertical plane object plane is a plane that is only at a close working distance from the front of the wearer and is perpendicular to the front line of sight.

[0131] Based on the above, the wearer's order information is entered into the system and the design parameters are calculated.

[0132] Then, the power distributions of the right-eye lens and the left-eye lens were designed in the same manner as in the conventional method. The above-mentioned maps (binocular visual field coordinates) were obtained using ray tracing for the designed power distributions for the right eye and the left eye.

[0133] Figure 3 This is a graph showing the diopter distribution R1 for the right eye, the diopter distribution L1 for the left eye, and the average value PW1 of both diopter distributions before the drawing is transitioned (equivalent to Comparative Example 1).

[0134] The eyeball model and other conditions for ray tracing are as follows.

[0135] Maximum accommodative power of the eye: 0.75D

[0136] Cornea-lens vertex distance (CVD): 14.5mm

[0137] Distance from corneal apex to eyeball's gyration center: 14.5mm

[0138] Unless otherwise specified, the above conditions are adopted in ray tracing. However, the present invention is not limited to the above conditions.

[0139] exist Figure 3 At the stage shown in , the right eye power distribution and the left eye power distribution have the same peak at X=0 as in the past. Figure 3 The power distribution R1 for the right eye shown in FIG is shifted by 3 degrees in the -X direction, and the power distribution L1 for the left eye is shifted by 3 degrees in the +X direction.

[0140] Figure 4 This is a graph showing the power distribution R2 for the right eye, the power distribution L2 for the left eye, and the average value PW2 of the two power distributions after the mapping is shifted (equivalent to Example 1).

[0141] For near working distance of 50cm, a refractive power of 1 / 0.5m=2.0D is necessary.

[0142] When the refractive power of the progressive-power lens is added to the accommodative power of the wearer A's eye, a refractive power of 2.0 D is sufficient. If the accommodative power of the eye is large, the wearer A experiences increased fatigue. Conversely, if the accommodative power of the eye is small, the wearer A experiences less fatigue.

[0143] For PW1 and PW2, calculate the difference between the 2.0 D of accommodation required for near work at a distance of 50 cm and the diopters measured at a horizontal section of the portion of the line of sight passing through the principal fixation line when looking directly at the near work distance of 50 cm with both eyes. This difference is the required self-accommodation for wearer A (unit: D).

[0144] Figure 5 This is a coordinate diagram related to Example 1 and Comparative Example 1, where the X-axis is the eyeball rotation angle difference [unit: degree] and the Y-axis is the self-adjustment amount [unit: D].

[0145] Watch Figure 5 In the case of PW2 in Example 1, the self-adjustment amount can be reduced compared to PW1 in Comparative Example 1. This tendency becomes more pronounced as the slew angle difference increases. As a result, the field of view in Example 1, where a small self-adjustment amount is sufficient, is wider than in Comparative Example 1.

[0146] As a result, the error in the near power in the horizontal direction centered on the front of the near vision is also reduced, so the wearing feeling during binocular vision is improved, and the feeling of a wider field of vision is obtained, which makes fatigue less likely.

[0147] [Example 2]

[0148] In the second embodiment, unlike the first embodiment, a case of different views is exemplified.

[0149] For wearer B, the following spectacle lenses were prepared.

[0150] Spherical power S of the lens for the right eye: 0.00D

[0151] Astigmatism degree C of the right eye lens: 0.00D

[0152] Spherical power of left eye lens: -4.00D

[0153] Astigmatism degree C of the left eye lens: 0.00D

[0154] Add degree ADD: 3.00D

[0155] Close working distance: 33.3cm

[0156] Other than the above, the same conditions as in Example 1 were employed.

[0157] Figure 6 This is a graph showing the diopter distribution for the right eye and the diopter distribution for the left eye after the plot is shifted and before the additional diopter distribution is converted and extracted.

[0158] Figure 6 The power distribution for the right eye shown in FIG has shifted by 3 degrees in the -X direction, and the power distribution for the left eye shown in FIG has shifted by 3 degrees in the +X direction.

[0159] The following describes the additional power distribution. The additional power distribution in one aspect of the present application is a power distribution obtained by simply subtracting a power distribution that is a part of the prescription value, that is, a prescription power distribution (distance power) from a power distribution for realizing the prescription in the spectacle lens of one aspect of the present application. In one aspect of the present application, the power distribution at the horizontal cross section is exemplified, but the present application is not limited to this aspect.

[0160] Figure 7 The coordinate graph of the right-eye power distribution Rl and the left-eye power distribution Ll and the average value PWl of the two power distributions before the drawing shift, which represents the additional power distribution that is a part of the power distribution constituting Figure 6 The coordinate graph of the right-eye power distribution Rl and the left-eye power distribution Ll and the average value PWl of the two power distributions before the drawing shift, which represents the additional power distribution that is a part of the power distribution constituting

[0161] Figure 8 The coordinate graph of the right-eye power distribution R2 and the left-eye power distribution L2 and the average value PW2 of the two power distributions after the drawing shift, which represents the additional power distribution that is a part of the power distribution constituting Figure 6 The coordinate graph of the right-eye power distribution R2 and the left-eye power distribution L2 and the average value PW2 of the two power distributions after the drawing shift, which represents the additional power distribution that is a part of the power distribution constituting

[0162] Figure 9 The coordinate graph of the right-eye power distribution R2 and the left-eye power distribution L2 and the average value PW2 of the two power distributions after the drawing shift, which represents the additional power distribution that is a part of the power distribution constituting

[0163] The viewing Figure 9 If it is the embodiment 2, the amount of accommodation can be reduced compared with the comparative example 2. In particular, the greater the angle of cyclotorsion, the more significant the tendency. As a result, in terms of the visual field area for which the amount of accommodation is small, the embodiment 2 is wider compared with the comparative example 2.

[0164] Thus, in the horizontal direction centered on the front surface for near use, the power error of the near power is smaller, and thus the wearing feeling at the time of binocular vision is improved, and the effect of feeling a wide visual field and becoming less likely to be tired is obtained.

[0165] In view of the above, the pair of progressive power lenses and the related technology in one aspect of the present application are preferably provided with the following provision. "From the wearer's viewpoint, when an object recognized is expressed by the angle of cyclotorsion with the movement of the line of sight in the right direction with respect to the central surface being positive and the movement of the line of sight in the left direction being negative, the angle of cyclotorsion of the object in front of the line of sight passing through the peak position of the additional power distribution in the power distribution for realizing the prescription power of the right eye with the right-eye lens is different in sign from the angle of cyclotorsion of the object in front of the line of sight passing through the peak position of the additional power distribution in the power distribution for realizing the prescription power of the left eye with the left-eye lens in the horizontal cross section of each lens area containing at least a part of the main line of sight."

[0166] It should be noted that the provision that "from the wearer's perspective, the object viewed is represented by the eye rotation angle difference, with the line of sight movement in the right direction relative to the median plane being positive and the line of sight movement in the left direction being negative" can be applied to one scheme of the present invention, and can also be applied to schemes other than different perspectives.

[0167] [Example 3]

[0168] The following experiment was conducted to obtain the preferred value expressed as the difference in the eyeball's rotation angle when the line of sight is moved horizontally from the main gaze line, regarding the degree of distance between the peak position of the diopter distribution at the horizontal cross-section of the lens for the right eye and the main gaze line, and the degree of distance between the peak position of the diopter distribution at the horizontal cross-section of the lens for the left eye and the main gaze line.

[0169] Figure 10 will be for Figure 4 The added power extracted from the transformation is represented as a power distribution diagram, showing the corresponding locations of the monocular maximum power MP, the binocular frontal vision average power BP, the visual field width W at the threshold, and the monocular maximum power position difference d. The maximum value of the added power for each eye is defined as the monocular maximum power MP, and the average value of the added power for frontal vision (i.e., the binocular frontal vision average power BP) is defined as the binocular frontal vision average power BP.

[0170] Furthermore, in Figure 10 In the embodiment, the maximum monocular power MP is consistent on the left and right. In different cases, the maximum value of the additional power of any eye can be set as the maximum monocular power MP, and the average of the maximum values ​​of the additional power of the left and right eyes can be set as the maximum monocular power MP.

[0171] In order to obtain the optimal amount of the swing angle difference as the offset amount, the following evaluation conditions are set.

[0172] (1) (maximum monocular power MP-average binocular power BP) ≤ 0.25D

[0173] This condition is used to eliminate the situation where the wearer may feel a sense of disharmony in appearance if there is a significant discrepancy between the maximum diopter of one eye and the front diopter of both eyes.

[0174] The maximum monocular power mentioned here is defined using the additional power distribution extracted by the transformation.

[0175] (2) (average power of binocular frontal vision BP-added power) > 0D

[0176] If the binocular frontal vision average power (BP) is too low compared to the prescribed addition power, the wearer may experience blurry vision and difficulty seeing objects. Therefore, this condition is used to evaluate the attenuation value of the binocular frontal vision average power.

[0177] (3) Field of view width W at the threshold (widening characteristic)

[0178] This condition ensures a wide field of vision that is only 0.50D, preferably 0.25D, lower than the prescribed add-on power. This corresponds to the range of vision that the wearer can see clearly using an adjustment of 0.25D (or 0.50D). W is a desirable property; the larger it is, the better.

[0179] The monocular maximum power position difference d, as the name implies, refers to a value obtained by subtracting the X coordinate [degrees] of the peak in the left-eye lens from the X coordinate [degrees] of the peak in the right-eye lens.

[0180] For wearer A, spectacle lenses with a spherical power S of 0.00 D, an astigmatism C of 0.00 D, and an addition power ADD of 3.00 D were prepared. Furthermore, the near working distance was 33.3 cm. A test was conducted in the same manner as in Example 1 except for these factors.

[0181] Figure 11 This is a graph related to Example 3, where the X-axis is the maximum diopter position difference d [degrees] for each eye, the central Y-axis related to evaluation conditions (1) and (2) is the diopter difference [D], and the right Y-axis related to evaluation condition (3) is the relative change in visual field width at the threshold [degrees]. The relative change in visual field width at the threshold, ΔW, is calculated by subtracting the visual field width at the threshold before the diopter distribution of the left and right eyes shifts in the X direction from the visual field width at the threshold after the shift, assuming W0. That is, ΔW = W - W0.

[0182] like Figure 11 As shown in , the area that satisfies (1) and (2) is an area sandwiched by horizontal straight lines located above and below. Moreover, the visual field width W at the threshold value of (3) has a widening characteristic. As a result, the widening characteristic value of (3) (i.e., the maximum value of the visual field width W at the threshold value in this area) becomes a value slightly lower than -6 degrees. As a result, it is preferred that the maximum diopter position difference d of the monocular eye is greater than -7 degrees (preferably -6 degrees) and less than -5 degrees. The fact that the maximum diopter position difference d of the monocular eye is -5 degrees means that the X coordinate of the lens for the right eye is negative and the Y coordinate of the lens for the right eye is positive. This is consistent with the example described in the preferred example in one embodiment of the present invention.

[0183] In view of the above, a pair of progressive-power lenses and related technologies in one embodiment of the present invention preferably have the following provisions.

[0184] "A pair of progressive-power lenses and related technologies, wherein the following evaluation conditions (1) and (2) are satisfied and the maximum diopter position difference d of the monocular eye is within the range of ±3 degrees (preferably ±2 degrees, more preferably ±1.5 degrees) of the desired characteristic value of (3) is present.

[0185] (1) (maximum monocular power MP-average binocular power BP) ≤ 0.25D

[0186] (2) (average power of binocular frontal vision BP-added power) > 0D

[0187] (3) The visual field width W (expected wide characteristic) is reduced by only 0.50D (preferably 0.25D) from the added power.

Claims

1. A pair of progressive addition lenses, consisting of a right-eye lens and a left-eye lens, in, The points on the right eye lens and the left eye lens through which the line of sight passes when viewing an object that exists on the wearer's median plane and is at a predetermined distance from the wearer when looking straight ahead are defined as the principal fixation lines. In order to make the visual field width at a predetermined diopter threshold wider than when the peaks of the diopter distribution at the horizontal cross section of the right-eye lens and the peaks of the diopter distribution at the horizontal cross section of the left-eye lens are located on the principal gaze line, In the diopter distribution at the horizontal cross section of the lens for the right eye, there is a peak at a position away from the main gaze line and toward the nose or ear side. In the power distribution at the horizontal cross section of the left-eye lens, there is a peak in a position away from the main gaze line and toward the nose side or the ear side in the opposite direction to the case of the right-eye lens.

2. A pair of progressive-power lenses according to claim 1, wherein: The distance between the peak position of the power distribution in the horizontal cross section of the right-eye lens and the main gaze line is equal to the distance between the peak position of the power distribution in the horizontal cross section of the left-eye lens and the main gaze line.

3. The pair of progressive-power lenses according to claim 1, wherein: The degree of distance between the peak position of the diopter distribution at the horizontal cross section of the lens for the right eye and the main gaze line and the degree of distance between the peak position of the diopter distribution at the horizontal cross section of the lens for the left eye and the main gaze line are both greater than 0 degrees and less than 5 degrees when expressed as the difference in the rotation angle of the eyeball when the line of sight is moved horizontally from the main gaze line.

4. The pair of progressive-power lenses according to claim 1, wherein: The peak position of the power distribution in the lens for the right eye is the position where the eyeball turns to the left from the main gaze line when viewed from the wearer, and the peak position of the power distribution in the lens for the left eye is the position where the eyeball turns to the right from the main gaze line when viewed from the wearer.

5. The pair of progressive-power lenses according to claim 1, wherein: In the power distribution on the right-eye lens or the left-eye lens, the portion having a peak at a position away from the main gaze line is at least between the distance power measurement point and the near power measurement point.

6. The pair of progressive-power lenses according to claim 1, wherein: In the power distribution of the right-eye lens or the left-eye lens, a portion having a peak at a position away from the main gaze line is at least the near portion.

7. The pair of progressive-power lenses according to claim 1, wherein: When the object being viewed is represented by the eye rotation angle difference in which the line of sight movement to the right relative to the midline is set to positive and the line of sight movement to the left relative to the midline is set to negative as viewed from the wearer, in the horizontal cross-section of each lens area including at least a portion of the main gaze line, the eye rotation angle difference of the object in front of the line of sight passing through the peak position of the additional power distribution in the power distribution of the prescription power for the right eye achieved with the right eye lens and the eye rotation angle difference of the object in front of the line of sight passing through the peak position of the additional power distribution in the power distribution of the prescription power for the left eye achieved with the left eye lens have different signs from each other.

8. A method for designing a pair of progressive-power lenses, the pair of progressive-power lenses consisting of a right-eye lens and a left-eye lens. in, When the wearer's eyesight passes through the right and left eye lenses when viewing an object that exists on the wearer's median plane and is at a predetermined distance from the wearer, the principal fixation lines are defined as follows: In order to make the visual field width at a predetermined diopter threshold wider than when the peaks of the diopter distribution at the horizontal cross section of the right-eye lens and the peaks of the diopter distribution at the horizontal cross section of the left-eye lens are located on the principal gaze line, In the diopter distribution at the horizontal cross section of the lens for the right eye, a peak is arranged at a position away from the main gaze line and toward the nose or ear side. In the power distribution at the horizontal cross section of the left-eye lens, a peak is arranged in a position away from the main gaze line and toward the nose side or the ear side in the opposite direction to that of the right-eye lens.

9. The method for designing a pair of progressive-power lenses according to claim 8, comprising: Binocular visual field coordinate acquisition process, wherein, Obtaining, in a horizontal cross section of an area including at least a portion of the principal gaze line, a right-eye diopter distribution that is converted into binocular visual field coordinates and that achieves the prescription diopter of the right eye using the right-eye lens, and a left-eye diopter distribution that is converted into binocular visual field coordinates and that achieves the prescription diopter of the left eye using the left-eye lens; a power distribution shifting step, wherein the power distribution for the right eye is shifted in one direction and the power distribution for the left eye is shifted in a direction opposite to the direction in which the power distribution for the right eye is shifted; a simulation step, wherein the offset of the left eye power distribution is set to a predetermined value, and the offset of the right eye power distribution is set to a predetermined value, and simulation is performed; and The determination step is to determine whether the simulation result satisfies a predetermined condition.

10. The method for designing a pair of progressive-power lenses according to claim 8 or 9, wherein: When the object viewed from the wearer's perspective is represented by the eye rotation angle difference with the line of sight moving in the right direction relative to the median plane being set to positive and the line of sight moving in the left direction being set to negative, in the horizontal cross-section of each lens area including at least a portion of the main gaze line, the eye rotation angle difference of the object in front of the line of sight passing through the peak position of the additional power distribution in the power distribution of the prescription power of the right eye achieved by the right eye lens and the eye rotation angle difference of the object in front of the line of sight passing through the peak position of the additional power distribution in the power distribution of the prescription power of the left eye achieved by the left eye lens have different signs from each other.

Images