Device for designing an ophthalmic lens, method for designing an ophthalmic lens and computer program product

Abstract

An eyeglass lens design device designs a pair of aspherical lenses, the pair of aspherical lenses having different powers between left and right, and the pair of aspherical lenses having rotational symmetry or axial symmetry at a part of a single-vision lens or a part of a single-vision lens of a progressive addition lens for a far prescription, the eyeglass lens design device including: an acquisition unit that acquires left prism amount information corresponding to a power of a left eye and right prism amount information corresponding to a power of a right eye; a calculation unit that calculates an operation value of a left prism amount and a right prism amount based on the left prism amount information and the right prism amount information; and a change unit that derives a change amount of a design parameter of one or both of an aspherical lens for the right eye and an aspherical lens for the left eye based on the operation value of the left prism amount and the right prism amount, and changes the design parameter based on the derived change amount of the design parameter.

Description

Technical Field

[0001] The embodiments of the present invention relate to a design apparatus, a design method and procedure for eyeglass lenses.

[0002] This application claims priority based on Japanese Patent Application No. 2021-012194 filed on January 28, 2021, the contents of which are incorporated herein by reference. Background Technology

[0003] When using spectacle lenses for refractive correction, visual distortion occurs due to the prismatic effect of the lenses. Current spectacle lenses reduce this distortion by making the front or back surfaces aspherical. In binocular vision, spatial depth is generally known to be perceived through retinal aberrations and convergence.

[0004] When the prescription for refractive correction differs between the two eyes, using spectacle lenses for correction results in different prismatic effects for each eye. Consequently, retinal aberrations and convergence vary significantly depending on the object's position. As a result, the likelihood of spatial distortion increases in binocular vision.

[0005] However, current eyeglass lens designs do not take into account the distortion of spatial recognition achieved through binocular vision.

[0006] A design method for a pair of eyeglass lenses consisting of a left eye lens and a right eye lens corresponding to the left and right eyes respectively is known (see, for example, Patent Document 1).

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent No. 5140768 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] The purpose of this invention is to provide a design device, a design method, and a procedure for eyeglass lenses that can reduce distortion when observing the surroundings through binocular vision.

[0012] Technical solutions for solving the problem

[0013] To address the aforementioned problems, one aspect of the present invention relates to a spectacle lens design apparatus that designs a pair of aspherical lenses with different prescriptions for the left and right eyes. Furthermore, the pair of aspherical lenses possesses rotational symmetry or axial symmetry in the single-focal portion of a monofocal or progressive lens prescription for distance vision. The spectacle lens design apparatus includes: an acquisition unit that, based on the relationship between the prescription power and prism amount of each of the multiple aspherical lenses, acquires information determining the left prism amount corresponding to the left eye's power and information determining the right prism amount corresponding to the right eye's power. The system includes: a right prism quantity information corresponding to the number; a calculation unit that calculates the calculated values ​​of the left and right prism quantities based on the information obtained by the acquisition unit; and a modification unit that, based on the calculated values ​​of the left and right prism quantities, derives the modification amount of the design parameters of one or both of the aspheric lenses for the right eye and the left eye, and modifies the design parameters of one or both of the aspheric lenses for the right eye and the left eye based on the modified design parameters.

[0014] One aspect of the present invention relates to a method for designing spectacle lenses, executed by a computer, for designing a pair of aspherical lenses with different diopters for the left and right eyes, and for the portion of the pair of aspherical lenses that is the single-focal lens in a monofocal or progressive lens prescription for distance vision to exhibit rotational symmetry or axial symmetry. The method comprises the following steps: based on the relationship between the prescription diopters and prism values ​​of the multiple aspherical lenses, obtaining information to determine the left prism value corresponding to the diopters of the left eye and information to determine the value corresponding to the diopters of the right eye. The information of the right prism quantity; based on the information of determining the left prism quantity and the information of determining the right prism quantity obtained in the step of obtaining, the calculated values ​​of the left prism quantity and the right prism quantity are calculated; and based on the calculated values ​​of the left prism quantity and the right prism quantity in the step of obtaining, the change amount of the design parameters of one or both of the aspheric lenses of the right eye and the aspheric lenses of the left eye is derived, and based on the change amount of the derived design parameters, the design parameters of one or both of the aspheric lenses of the right eye and the aspheric lenses of the left eye are changed.

[0015] One aspect of the present invention relates to a program that causes a computer to perform the following steps: based on the relationship between the prescription power and prism amount of a plurality of aspherical lenses, obtaining information to determine the left prism amount corresponding to the power of the left eye and information to determine the right prism amount corresponding to the power of the right eye, wherein the plurality of aspherical lenses have rotational symmetry or axial symmetry in the monofocal lens portion of a monofocal lens or progressive lens for the distance prescription; calculating calculated values ​​of the left and right prism amounts based on the information to determine the left and right prism amounts obtained in the obtaining step; and deriving a change in the design parameters of one or both of the aspherical lenses for the right eye and the aspherical lenses for the left eye based on the calculated values ​​of the left and right prism amounts in the calculating step, and changing the design parameters of one or both of the aspherical lenses for the right eye and the aspherical lenses for the left eye based on the derived change in the design parameters.

[0016] Invention Effects

[0017] According to embodiments of the present invention, a design apparatus, a design method, and a procedure for eyeglass lenses that can reduce distortion when observing the surroundings through binocular vision can be provided. Attached Figure Description

[0018] Figure 1 This is a diagram illustrating the spectacle lens processing system according to this embodiment.

[0019] Figure 2A This is a diagram illustrating an example of the relationship between optimization parameters and spherical degree error and astigmatism.

[0020] Figure 2B This is a diagram illustrating an example of the relationship between optimization parameters and spherical degree error and astigmatism.

[0021] Figure 3 This is a diagram illustrating an example of the relationship between optimized parameters and the prism at the periphery of the lens.

[0022] Figure 4 This is a diagram illustrating an example of the relationship between spherical power and the prism at the periphery of the lens.

[0023] Figure 5 This is a diagram illustrating an example of information stored in the design device according to this embodiment, representing the relationship between the spherical power (D) and the prisms at the periphery of the lens.

[0024] Figure 6 This is a diagram illustrating an example of the processing of the design apparatus involved in this embodiment.

[0025] Figure 7This is a diagram illustrating an example of a lens design implemented by the design device involved in this embodiment.

[0026] Figure 8 This is a diagram illustrating an example of a lens design implemented by the design device involved in this embodiment.

[0027] Figure 9 This is a diagram illustrating an example of a lens design implemented by the design device involved in this embodiment.

[0028] Figure 10 This is a diagram illustrating an example of the operation of the design device involved in this embodiment.

[0029] Figure 11 This diagram illustrates spatial recognition through binocular vision.

[0030] Figure 12 This diagram illustrates a method for evaluating spatial vision using binocular vision.

[0031] Figure 13 This is a diagram illustrating an example of the evaluation results of spatial vision performed through binocular vision.

[0032] Figure 14 This is a diagram used to illustrate an example of the evaluation results of spatial vision performed through binocular vision.

[0033] Figure 15 This is a diagram illustrating another example of a lens design implemented by the design device involved in this embodiment.

[0034] Figure 16 This is a diagram illustrating another example of a lens design implemented by the design device involved in this embodiment. Detailed Implementation

[0035] <Implementation Method>

[0036] Hereinafter, with reference to the accompanying drawings, an eyeglass lens processing system according to an embodiment of the present invention will be described. Figure 1 This diagram illustrates the spectacle lens processing system according to this embodiment. The spectacle lens processing system 1 includes a store terminal device 100, an order receiving device 150, a design device 200, and a processing device 300.

[0037] The store terminal device 100 and the order-taking device 150 communicate via a network NW. The network NW may include, for example, the Internet, WAN (Wide Area Network), LAN (Local Area Network), vendor equipment, wireless base stations, etc.

[0038] One example of a store terminal device 100 is installed in an optical shop 10. The optical shop 10 orders eyeglass lenses corresponding to prescriptions given to customers who wear eyeglasses.

[0039] An example of an order-accepting device 150, a design device 200, and a processing device 300 is provided in an eyeglass lens processing facility 20. The eyeglass lens processing facility 20 accepts orders for eyeglass lenses from an optical shop 10. The eyeglass lens processing facility 20 designs the ordered eyeglass lenses based on a prescription. The eyeglass lens processing facility 20 manufactures the eyeglass lenses by processing them based on the design results.

[0040] This describes the optical shop 10 and the eyeglass lens processing site 20.

[0041] [Eyeglasses store 10]

[0042] The eyewear store 10 is equipped with a store terminal device 100. The store terminal device 100 can be a smartphone, mobile terminal, personal computer, tablet computer, or other information processing device. The store terminal device 100 contains software for ordering eyeglass lenses from the eyeglass lens processing facility 20.

[0043] The store terminal device 100 is equipped with a mouse, keyboard, etc. Sales staff in the optical shop 10 input lens data and frame data into the store terminal device 100 by operating the mouse, keyboard, etc.

[0044] Lens data includes, for example, prescription values, wearing conditions for the lenses, lens types, and layout data corresponding to the customer's expectations. Prescription values ​​include the base curve, spherical refractive power, astigmatic refractive power, astigmatic axis direction, prism refractive power, prism base direction, spherical power, additional power, and interpupillary distance (PD). Wearing conditions include interapex distance, tilt angle, and frame elevation angle. Lens types include monofocal spherical lenses, monofocal aspherical lenses, multifocal lenses (bifocal, progressive), and coatings (tinted, hard coating, anti-reflective, UV-resistant, etc.).

[0045] The frame data includes the shape data of the frame selected by the customer. The frame data is obtained by measuring the shape of the frame at the time of ordering using a device that measures the shape of the frame. The obtained frame data is then input into the store terminal device 100. Alternatively, frame data can also be managed via barcode labels, for example, by reading the barcode label affixed to the frame using a barcode reader and inputting it into the store terminal device 100.

[0046] The store terminal device 100 generates order data including lens data and frame data, and generates an order request containing the generated order data, with the design device 200 as the recipient. The store terminal device 100 sends the generated order request to the design device 200.

[0047] [Eyeglass lens processing site 20]

[0048] The spectacle lens processing facility 20 includes an order receiving device 150, a design device 200, and a processing device 300. A LAN (Local Area Network) centered on the order receiving device 150 is constructed within the spectacle lens processing facility 20, connecting the design device 200 and the processing device 300 to the LAN.

[0049] The order-accepting device 150 is implemented as a smartphone, mobile terminal, personal computer, tablet terminal device, or other information processing device. The order-accepting device 150 is equipped with software for accepting orders for eyeglass lenses from the optical shop 10. The order-accepting device 150 receives an order request sent by the shop terminal device 100. The order-accepting device 150 obtains the order data contained in the order request. Based on the obtained order data, the order-accepting device 150 processes the order for eyeglass lenses.

[0050] In the eyeglass lens processing facility 20, after the order receiving device 150 obtains the order data, the unprocessed block parts are designed and processed on both the inner and outer surfaces in a manner that satisfies the prescription given to the wearer.

[0051] In addition, in the eyeglass lens processing area 20, in order to improve productivity, the entire range of prescriptions can be divided into multiple groups, and semi-finished blanks with an outer surface (convex) curve shape (spherical or aspherical) and lens diameter suitable for each group of prescription ranges can be prepared in advance for eyeglass lens orders.

[0052] In this case, at the spectacle lens processing facility 20, spectacle lenses suitable for the wearer's prescription are manufactured solely through inner surface (concave) processing (and lens shape processing). The order receiving device 150 generates a design request containing order data, with the design device 200 as the recipient. The order receiving device 150 then sends the generated design request to the design device 200.

[0053] The design device 200 is implemented as a smartphone, mobile terminal, personal computer, tablet terminal device, or other information processing device. The design device 200 receives a design request sent by the order acceptance device 150. The design device 200 obtains the order acceptance data contained in the received design request. The design device 200 is equipped with a program for designing eyeglass lenses based on the order acceptance data.

[0054] The design device 200 generates lens design data based on the lens data included in the acquired order data, and generates lens shape processing data based on the frame data included in the order data. The design method for spectacle lenses will be described later.

[0055] The design device 200 generates a processing request, which includes the lens design data and lens shape processing data, and sends the request to the processing device 300. The design device 200 then sends the generated processing request to the processing device 300.

[0056] The processing device 300 can be a smartphone, mobile terminal, personal computer, tablet terminal device, or other information processing equipment.

[0057] The operator places the block part on a processing machine (not shown) such as a curve generator and starts the processing operation on the processing device 300.

[0058] The processing apparatus 300 receives a processing request sent by the design apparatus 200. The processing apparatus 300 acquires the lens design data and lens shape processing data contained in the received processing request. Based on the acquired lens design data and lens shape processing data, the processing apparatus 300 performs drive control on the processing machine.

[0059] The processing machine grinds and polishes the inner and outer surfaces of the block parts according to the lens design data to create the inner and outer surface shapes of the eyeglass lens.

[0060] Subsequently, based on the order data, various coatings such as dyeing, hard coating, anti-reflective film, and anti-ultraviolet coating are applied to the eyeglass lenses.

[0061] After coating, the outer peripheral surface of the unprocessed lens, after the inner and outer surface shapes have been formed, is machined into an edge shape corresponding to the lens shape. This machining can be performed either at the spectacle lens processing facility 20 or at the optician's shop 10. Thus, the spectacle lens is completed and delivered to the optician's shop 10.

[0062] [Eyeglass Lens Design Methods]

[0063] This section explains the design method for spectacle lenses. In the following description, we envision the design of a pair of aspherical lenses. These aspherical lenses are spectacle lenses with different left and right prescriptions (spherical power, etc.) for wearers with different vision. Furthermore, the single-focal portion of the monofocal lens (for distance vision) in a monofocal or progressive lens prescription exhibits rotational symmetry or axial symmetry. The following explanation continues with an example of a prescription power applied using spherical power.

[0064] Generally, aberrations in eyeglass lenses increase from the center to the periphery, leading to a decrease in visual quality. Peripheral aberrations can be suppressed by making the front or back surface, or both surfaces (front and back), aspherically shaped. However, even with aspherical optimization, it's impossible to eliminate all aberrations in a two-surface structure like an eyeglass lens.

[0065] Figure 2A This is a diagram illustrating an example of the relationship between optimization parameters and spherical degree error and astigmatism. Figure 2A This shows how the spherical degree error and astigmatism change at a specific point in the periphery when the optimization parameter (α) is changed.

[0066] Here, the optimization parameter (α) is an example of a parameter (design parameter) used to adjust the design objective. The optimization parameter (α) is a parameter that changes the ratio of spherical error to astigmatism (a weighted average of the two objectives during optimization), which is the design objective. Here, the objective refers to the target values ​​of spherical error and astigmatism on the axis being optimized when performing aspherical optimization. The difference between the spherical error ΔP(r) and the prescription value is expressed in terms of the position r in the radial direction on the axis, and optimization is performed in a way that minimizes the sum of the absolute values ​​of all aberrations (error function) E(r) = |ΔP(r)| + |ΔC(r)|.

[0067] The error function of the optimization objective, which minimizes |ΔP(r)| and |ΔC(r)| by designing the value of parameter α, is expressed by the following formula.

[0068] E(r,α)=α×|ΔP(r)|+(1-α)|ΔC(r)|

[0069] Regarding the position r in the radial direction, by weighting and summing r, the total error function on the axis is obtained, and the aspherical coefficient is optimized. The weighting of r may vary depending on the type of product, the shape and size of the lens being optimized, etc.

[0070] Among the aberrations in lenses, spherical power error and astigmatism have the greatest impact on vision. By changing the optimization objectives, it is possible to design in a way that emphasizes both spherical power error and astigmatism.

[0071] Figure 2B An example illustrating the relationship between optimization parameters and spherical degree error and astigmatism is shown. Figure 2B In the diagram, the horizontal axis represents the optimization parameter (α), and the vertical axis represents the spherical power error and astigmatism at a specific position from the optical center. The spherical power error is represented by a solid line, and the astigmatism is represented by a dashed line.

[0072] According to Figure 2, as the spherical degree error decreases, astigmatism increases, and as the spherical degree error increases, astigmatism decreases.

[0073] As can be seen from the above, by changing the optimization parameter (α), the ratio of spherical degree error to astigmatism can be changed.

[0074] Figure 3 This illustrates an example of the relationship between optimized parameters and the prism at the periphery of the lens. Figure 3 In the diagram, the horizontal axis represents the optimization parameter (α), and the vertical axis represents the prism at the periphery of the lens. According to... Figure 3 The value (quantity) of the prism at the periphery of the lens varies linearly with respect to the optimization parameter (α).

[0075] As can be seen from the above, by changing the optimization parameter (α), the value (amount) of the prism in the peripheral part of the lens can be changed.

[0076] Figure 4 An example illustrating the relationship between the spherical power (D) and the peripheral portion of a prism. Figure 4 In the diagram, the horizontal axis represents the spherical power (D), and the vertical axis represents the prism at the periphery of the lens. Figure 4 This shows the prism values ​​(quantities) at the periphery of the lens when optimized with the same optimization parameter (α). The case where light from the eye refracts in a diverging direction is defined as positive, and the case where light refracts in a converging direction is defined as negative.

[0077] according to Figure 4 As the spherical power (D) increases, the prism value (quantity) of the peripheral portion of the lens decreases monotonically. That is, it can be seen that the prism value (quantity) of the peripheral portion of the lens varies according to the lens prescription (spherical power (D)). The larger the absolute value of the spherical power (D), the larger the absolute value of the prism value (quantity) of the peripheral portion of the lens.

[0078] As described above, when the prescriptions (power) for both eyes are different, the prism value (amount) at the periphery of the lenses for both eyes will differ.

[0079] Design device 200 acquires order acceptance data contained in a design request received from order acceptance device 150. Based on the lens data contained in the acquired order data, design device 200 derives design parameters for a baseline design. Based on the derived design parameters, design device 200 performs a baseline design. For example, the baseline design for a monofocal lens is set as a design assuming identical prescriptions for both eyes, but this design varies depending on the product.

[0080] When the prescriptions for both eyes are different, the design device 200 reduces the difference in the amount of prisms at the peripheral portion of the lenses for both eyes compared to a baseline design. The design device 200 acquires information determining the amount of the left prism corresponding to the power of the left eye and information determining the amount of the right prism corresponding to the power of the right eye. Based on the acquired information determining the amount of the left prism and the information determining the amount of the right prism, the design device 200 calculates calculated values ​​for the amounts of the left and right prisms.

[0081] Design device 200 derives the change in design parameters compared to the baseline design based on the calculated values ​​of the left and right prisms. Design device 200 then modifies the design parameters based on this change. By modifying the design parameters, the design objective is thus altered.

[0082] Design device 200 generates lens design data including design parameters, design objectives, etc. Return to Figure 1 Let's continue with the explanation.

[0083] Provide details of the design device 200.

[0084] The design device 200 includes a communication unit 202, a processing unit 203, an acquisition unit 204, a calculation unit 205, a modification unit 206, a production unit 207, and a storage unit 210.

[0085] The communication unit 202 is implemented via a communication module. The communication unit 202 communicates with communication devices in the eyeglass lens processing facility 20, such as the order receiving device 150 and the processing device 300, via a LAN. The communication unit 202 communicates, for example, via a wired LAN. Alternatively, the communication unit 202 can also communicate via wireless communication methods such as wireless LAN, Bluetooth (registered trademark), or LTE (registered trademark).

[0086] Specifically, the communication unit 202 receives the design request sent by the order receiving device 150. The communication unit 202 obtains the processing request output by the manufacturing unit 207. The communication unit 202 sends the obtained processing request to the processing device 300.

[0087] The storage unit 210 is implemented using HDD (Hard Disk Drive), flash memory, RAM (Random Access Memory), ROM (Read Only Memory), etc. The storage unit 210 stores programs for designing spectacle lenses and information representing the relationship between the spherical power (D) and the prisms at the periphery of the lens.

[0088] Figure 5 This diagram illustrates an example of information stored in the design device according to this embodiment, representing the relationship between the spherical power (D) and the prisms at the periphery of the lens. Figure 5 In the diagram, the horizontal axis represents the spherical power (D), and the vertical axis represents the prism at the periphery of the lens. Figure 5 In the example below, the relationship between the spherical power (D) and the prism of the peripheral portion of the lens is shown for lenses D1 and D2, respectively. Lens D1 is represented by a solid line, and lens D2 by a dashed line. The case where light rays from the eye refract in a diverging direction is defined as positive, and the case where light rays refract in a converging direction is defined as negative.

[0089] An example of the peripheral portion of the lens is preferably located at a position 5 mm or more but less than 50 mm from the optical center of the lens in the horizontal direction. An even more preferred example of the peripheral portion of the lens is located at a position 10 mm or more but less than 30 mm from the optical center of the lens in the horizontal direction.

[0090] An example of lens D1 and lens D2 is an aspheric lens with rotational or axial symmetry in the single-focal portion of a single-focal prescription or progressive lens for distance vision. Lens D1 and lens D2 are obtained by optimizing the design objectives according to different optimization parameters (α).

[0091] according to Figure 5 It can be seen that, for lenses D1 and D2, as the spherical power (D) increases, the prism value (amount) at the periphery of the lens decreases monotonically. It can also be seen that the larger the absolute value of the spherical power (D), the larger the absolute value (amount) of the prism. Regarding lenses D1 and D2, it is known that the change in the prism value (amount) at the periphery of the lenses relative to the spherical power (D) is different.

[0092] As described above, the prism value (amount) of the peripheral portion of the lens varies depending on the lens prescription, such as the spherical power (D). Different prescriptions for each eye will result in different prism values ​​(amounts). Return to Figure 1 Let's continue with the explanation.

[0093] Processing unit 203 receives the design request received by communication unit 202 and obtains the ordering data included in the received design request. Based on the lens data included in the ordering data, processing unit 203 derives design parameters for a baseline design. Design device 200 performs a baseline design based on the derived design parameters. An example of a baseline design is a design assuming the prescriptions for both eyes are the same. This design varies depending on the product. Processing unit 203 generates lens shape processing data based on the frame data included in the ordering data.

[0094] The acquisition unit 204 acquires the design request received by the communication unit 202, and acquires the ordering data included in the acquired design request. The acquisition unit 204 acquires the spherical power included in the lens data contained in the ordering data. The spherical power includes information for determining the spherical power of the left eye and information for determining the spherical power of the right eye.

[0095] Based on information about determining the spherical power of the left eye and information about determining the spherical power of the right eye, the acquisition unit 204 obtains information from the information stored in the storage unit 210 that represents the relationship between the spherical power (D) and the prisms at the periphery of the lens, which determines the value (amount) of the left prism corresponding to the spherical power of the left eye and the value (amount) of the right prism corresponding to the spherical power of the right eye.

[0096] Figure 6 This diagram illustrates an example of the processing of the design apparatus according to this embodiment. Figure 6 In the diagram, the horizontal axis represents the spherical power (D), and the vertical axis represents the prism at the periphery of the lens. Figure 6 Showing about Figure 5 The example shown is a case where lens D1 of lens D1 and lens D2 are optimized by adjusting two optimization parameters (α) respectively, with the spherical power of one eye set to S1 and the spherical power of the other eye set to S2.

[0097] The acquisition unit 204 acquires 10 as the prism value (quantity) corresponding to the spherical degree S1, and acquires 8 as the prism value (quantity) corresponding to the spherical degree S2. Return to Figure 1 Let's continue with the explanation.

[0098] The calculation unit 205 acquires information obtained by the acquisition unit 204 regarding the value (quantity) of the left prism corresponding to the spherical power of the left eye and the value (quantity) of the right prism corresponding to the spherical power of the right eye.

[0099] The calculation unit 205 derives a calculated value for the left prism based on the obtained information determining the value (quantity) of the left prism corresponding to the spherical power of the left eye and the value (quantity) of the right prism corresponding to the spherical power of the right eye. An example of this calculated value is the difference between the left and right prism values.

[0100] Next, we will continue to explain the case where the difference between the value (quantity) of the left prism and the value (quantity) of the right prism is used as an example of an operational value.

[0101] Reference Figure 6 Please provide an explanation. For example... Figure 6 As shown, the value (quantity) of the prism corresponding to the spherical degree S1 is 10, and the value (quantity) of the prism corresponding to the spherical degree S2 is 8. The calculation unit 205 calculates 2 as the difference ΔP1 between the values ​​(quantities) of the prism corresponding to the spherical degree S1 and the prism corresponding to the spherical degree S2.

[0102] The modification unit 206 obtains the difference ΔP1 between the value (quantity) of the left prism and the value (quantity) of the right prism from the calculation unit 205. Based on the obtained difference ΔP1 between the left and right prism values, the modification unit 206 modifies the design parameters of one or both of the aspherical lenses for the right eye and the left eye compared to the design parameters of the reference design. The modification unit 206 derives the change amount of the design parameters based on the difference ΔP1 between the left and right prism values. The change amount of the design parameters is the change amount of the design parameters derived from the difference between the left and right prism values ​​compared to the design parameters of the reference design. Alternatively, the difference ΔP1 between the left and right prism values ​​can be associated with the change amount of the design parameters.

[0103] For example, when the difference ΔP1 between the values ​​(quantities) of the left and right prisms is 0, the change unit 206 sets the change amount of the design parameter to 0. When the difference ΔP1 between the values ​​(quantities) of the left and right prisms is 0.1, the change unit 206 sets the change amount of the design parameter to 1. When the difference ΔP1 between the values ​​(quantities) of the left and right prisms is 0.2, the change unit 206 sets the change amount of the design parameter to 2.

[0104] However, the modification unit 206 limits the amount of change of the design parameters to the limit value based on the limit value of the change amount of the design parameters.

[0105] Specifically, let's explain the case where the limit for the change amount of the design parameter is set to 2. When the difference ΔP1 between the values ​​(quantities) of the left and right prisms is 0.1, the change unit 206 sets the change amount of the design parameter to 1. When the difference ΔP1 between the values ​​(quantities) of the left and right prisms is 0.2, the change unit 206 sets the change amount of the design parameter to 2. When the difference ΔP1 between the values ​​(quantities) of the left and right prisms is 0.3, if the change amount of the design parameter is set to 3, it exceeds the limit of 2; therefore, the change amount of the design parameter is set to 2.

[0106] like Figure 6 As shown, this illustrates the case where the absolute value of the spherical power S1 is greater than the absolute value of the spherical power S2. The modification unit 206 obtains the difference ΔP1 between the prism value (amount) calculated based on the prism value (amount) of the peripheral portion of the lens corresponding to the spherical power S1 of lens D1 and the prism value (amount) of the peripheral portion of the lens corresponding to the spherical power S2 of lens D1.

[0107] On the other hand, when the value (quantity) of the prism at the periphery of the lens corresponding to the smaller absolute value of the spherical power, namely the spherical power S2, is obtained from the lens D2 whose design parameter (α) is different from that of the lens D1 (based on the benchmark design), the difference ΔP2 of the prism value (quantity) is calculated based on the value (quantity) of the prism at the periphery of the lens corresponding to the spherical power S1 of the lens D1 and the value (quantity) of the prism at the periphery of the lens corresponding to the spherical power S2 of the lens D2.

[0108] The prism value (quantity) corresponding to the spherical power S2 of lens D2 is 8.5. Therefore, based on the prism value (quantity) of the peripheral portion of the lens corresponding to the spherical power S1 of lens D1 and the prism value (quantity) of the peripheral portion of the lens corresponding to the spherical power S2 of lens D2, the difference ΔP2 of the prism value (quantity) is 1.5.

[0109] Since the difference in prism values ​​(quantities) ΔP2 < the difference in prism values ​​(quantities) ΔP1, the difference in prism values ​​(quantities) between the two lenses becomes smaller when using lens D2 compared to using lens D1, regarding the spherical power S2. In this case, the modification unit 206 changes the design parameters of lens D2 regarding the spherical power S2.

[0110] Figure 7 This is a diagram illustrating an example of a lens design implemented by the design device according to this embodiment. Figure 7 The diagram shows spherical power error, astigmatism, and prism for both the baseline design and binocular design, specifically for the right and left eyes. Furthermore, regarding prisms, the difference in prism values ​​between the two eyes is shown. "△" is the unit of measurement for prism diopter.

[0111] Binocular design is achieved by altering the design parameters of both eyes compared to the baseline design. The prism value is a calculated value at a position 30mm from the center of the lens. As an example, a prescription of S-4.00D for the right eye and S-3.50D for the left eye is shown.

[0112] according to Figure 7 Regarding spherical power error, for the right eye lens, it changes from 0.17D in the standard design to 0.31D in the binocular design; for the left eye lens, it changes from 0.14D in the standard design to 0.04D in the binocular design. Regarding astigmatism, for the right eye lens, it changes from 0.70D in the standard design to 0.54D in the binocular design; for the left eye lens, it changes from 0.63D in the standard design to 0.74D in the binocular design. Regarding prism value (quantity), for the right eye lens, it changes from 17.62△ in the standard design to 17.27△ in the binocular design; for the left eye lens, it changes from 15.10△ in the standard design to 15.38△ in the binocular design. Regarding the difference in prism between the two eyes, it changes from 2.52△ in the standard design to 1.89△ in the binocular design.

[0113] As can be seen from the above, by changing the design parameter (α) to change the binocular design from the baseline design to the binocular design, the absolute value of the difference in the amount of prisms between the two eyes is reduced from 2.52△ in the baseline design to 1.89△ in the binocular design.

[0114] Figure 8 This is a diagram illustrating an example of a lens design implemented by the design device according to this embodiment. Figure 8 In the diagram, the horizontal axis represents the radius r (mm), and the vertical axis represents the prism. Figure 8 In Figure 7 Under the same conditions, the relationship between the radius and the prism is shown. In the baseline design, the right eye lens is represented by a solid black line, and the left eye lens by a solid gray line. In the binocular design, the right eye lens is represented by a dashed black line, and the left eye lens by a dashed gray line.

[0115] according to Figure 8 In both the baseline and binocular designs, the prism (Δ) of both the right and left eye lenses increases with increasing radius. In both designs, the prism (Δ) of the right eye lens is greater than that of the left eye lens.

[0116] At a radius of 15 mm or more, the difference between the prism value (quantity) of the right eye lens in the baseline design and the prism value (quantity) of the right eye lens in the binocular design becomes significant. At a radius of 20 mm or more, the difference between the prism value (quantity) of the left eye lens in the baseline design and the prism value (quantity) of the left eye lens in the binocular design becomes significant.

[0117] Figure 9 This is a diagram illustrating an example of a lens design implemented by the design device according to this embodiment. Figure 8 In the figure, the horizontal axis is the radius r (mm), and the vertical axis is the difference between the two prisms (Δ). Figure 9 In Figure 7 Under the same conditions, the relationship between radius r and the difference between the binocular prisms is shown. In the difference between the binocular prisms (Δ), the baseline design is represented by a solid line, and the binocular design is represented by a dashed line.

[0118] The difference in prism values ​​(quantities) between the two eyes in the baseline design is the difference between the prism values ​​(quantities) of the right eye lens and the left eye lens in the baseline design. The difference in prism values ​​(quantities) between the two eyes in the binocular design is the difference between the prism values ​​(quantities) of the right eye lens and the left eye lens in the binocular design.

[0119] according to Figure 9 It can be seen that the prism values ​​(quantities) of the two eyes in the binocular design are less than the difference in prism values ​​(quantities) of the two eyes in the baseline design. It can also be seen that the larger the radius r, the larger this difference. Return to Figure 1 Let's continue with the explanation.

[0120] Production unit 207 obtains lens design data and information on the amount of change in design parameters from modification unit 206. Production unit 207 obtains lens shape processing data from processing unit 203. Production unit 207 generates a processing request, with processing device 300 as the receiving end, which includes the obtained lens design data, information on the amount of change in design parameters, and lens shape processing data. Production unit 207 outputs the generated processing request to communication unit 202.

[0121] The processing unit 203, acquisition unit 204, calculation unit 205, modification unit 206, and production unit 207 are implemented, for example, by executing a computer program (program for designing eyeglass lenses) stored in the storage unit 210 (software) through a hardware processor such as a CPU (Central Processing Unit).

[0122] In addition, some or all of these functional units can be implemented either through hardware (including the circuitry) such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), and GPU (Graphics Processing Unit), or through the collaboration of software and hardware.

[0123] Computer programs can be pre-stored in storage devices such as HDDs and flash memory, or stored in removable storage media such as DVDs and CD-ROMs, and installed by assembling the storage media into a drive device.

[0124] (The operation of the design device 200)

[0125] Figure 10 An example of the operation of the design apparatus according to this embodiment is shown. Here, the actions of the design apparatus 200 after receiving a design request sent by the order receiving device 150, deriving design parameters of a baseline design based on the information contained in the received design request, and performing the baseline design based on the derived design parameters of the baseline design will be described.

[0126] (Step S1)

[0127] In the design device 200, the acquisition unit 204 acquires the design request received by the communication unit 202 and acquires the ordering data included in the acquired design request. The acquisition unit 204 acquires the lens data included in the ordering data, and based on the information containing the information on determining the spherical power of the left eye included in the acquired lens data, it acquires the information on determining the value (amount) of the prism of the left eye in the reference design corresponding to the spherical power of the left eye from the information stored in the storage unit 210 that represents the relationship between the spherical power and the prisms of the peripheral portion of the lens.

[0128] (Step S2)

[0129] In the design device 200, the acquisition unit 204 obtains information from the information stored in the storage unit 210 that indicates the relationship between the spherical power and the prisms in the peripheral portion of the lens, based on the information containing the information on determining the spherical power of the right eye. This information determines the value (amount) of the prism for the right eye in the reference design corresponding to the spherical power of the right eye.

[0130] (Step S3)

[0131] In the design device 200, the calculation unit 205 acquires information obtained by the acquisition unit 204 regarding the value (quantity) of the left prism corresponding to the spherical power of the left eye in the determination reference design, and the value (quantity) of the right prism corresponding to the prescription power of the right eye in the determination reference design. Based on the acquired information regarding the value (quantity) of the left prism corresponding to the spherical power of the left eye and the value (quantity) of the right prism corresponding to the prescription power of the right eye, the calculation unit 205 calculates the difference ΔP1 between the value (quantity) of the left prism and the value (quantity) of the right prism.

[0132] (Step S4)

[0133] In the design device 200, the modification unit 206 obtains the difference ΔP1 between the value (quantity) of the left prism and the value (quantity) of the right prism from the calculation unit 205. Based on the obtained difference ΔP1 between the value (quantity) of the left prism and the value (quantity) of the right prism, the modification unit 206 derives the amount of change in the design parameters of one or both of the right eye lens and the left eye lens compared to the design parameters of the reference design.

[0134] (Step S5)

[0135] In the design device 200, the modification unit 206 modifies the design parameters of one or both of the right eye lens and the left eye lens compared to the design parameters of the reference design based on the amount of change in the derived design parameters.

[0136] This illustrates spatial recognition through binocular vision.

[0137] Figure 11 This diagram illustrates spatial recognition through binocular vision. Figure 11 The results of ray tracing from the left eye (LE) and right eye (RE) are shown. Here, the left eye (LE) has weak myopia, and the right eye (RE) has strong myopia.

[0138] Spatial recognition via binocular vision relies on cues such as binocular parallax on the retina and convergence of the eyes. Therefore, by using the position of the pupil or the rotation point of the eyeball as a reference, the light rays are traced to the object point, and the intersection of the light rays from both eyes is calculated, thereby enabling the evaluation of the position of the object point recognized by binocular vision.

[0139] When wearing eyeglasses, light rays from the pupil or the point of rotation of the eyeball are refracted by the lenses, thus causing a shift in the perceived position of an object compared to its actual position. For example... Figure 11 As shown, ray tracing from both eyes is performed on a group of objects in real space, thereby enabling an evaluation of how space can be identified through binocular vision.

[0140] In particular, such as Figure 11 As shown, when the right and left eyes have different prescription powers (spherical powers), the absolute value of the prism value (magnitude) at the periphery of the lens is larger compared to the lens with a smaller absolute value. Therefore, when wearing eyeglasses with different prescription powers (spherical powers) for the right and left eyes, the difference in position between object points in space appears larger compared to the naked eye, leading the wearer to perceive spatial distortion.

[0141] Explain the evaluation method for spatial vision using binocular vision.

[0142] Figure 12 This diagram illustrates a method for evaluating spatial vision using binocular vision. When observing with binocular vision, the convergence angle is θcre for the naked eye and θcim for the eye wearing glasses.

[0143] The change in the convergence angle (θcim - θcre) relative to the naked eye when observing with glasses is calculated. The convergence angle is related to the sense of distance perceived through binocular vision. Therefore, the smaller the difference between the convergence angle θcre under naked-eye conditions and the convergence angle θcim under glasses conditions, the closer spatial vision can be to that of the naked eye.

[0144] Furthermore, the smaller the difference in the convergence angle between the right and left eyes, the smaller the difference in the perceived spatial distance between the left and right sides. Therefore, it is assumed that the smaller the difference in the right and left convergence angle, the less spatial distortion will be.

[0145] This is an example illustrating the evaluation results of spatial vision using binocular vision.

[0146] Figure 13 This is a figure illustrating Example 1, showing the evaluation results of spatial vision performed through binocular vision. Figure 13 In the diagram, the horizontal axis represents the radius r (mm), and the vertical axis represents the change in the convergence angle (deg). The change in the convergence angle (deg) is represented by a solid line for the baseline design and by a dashed line for the binocular design.

[0147] The change in convergence angle in the baseline design is the change in convergence angle (θcim - θcre) relative to the naked eye when observing through binocular vision in the baseline design while wearing glasses.

[0148] according to Figure 13It can be seen that the larger the radius, the greater the change in convergence angle (deg) in both the baseline design and the binocular design. Furthermore, the larger the absolute value of the radius, the greater the difference between the change in convergence angle in the baseline design and the change in convergence angle in the binocular design.

[0149] Figure 14 This is a diagram used to illustrate an example of the evaluation results of spatial vision through binocular vision. Figure 14 In the diagram, for both the baseline design and the binocular design, the changes in the convergence angle at position X-24mm on the lens, the changes in the convergence angle at position X+24mm on the lens, and the difference in the changes in the left and right convergence angles are shown.

[0150] according to Figure 14 Regarding the change in convergence angle at position X-24mm on the lens, it changes from -1.01 [deg] in the standard design to -0.88 [deg] in the binocular design. Regarding the change in convergence angle at position X+24mm on the lens, it changes from 0.40 [deg] in the standard design to 0.26 [deg] in the binocular design. Regarding the difference between the left and right lenses, it changes from 1.41 [deg] in the standard design to 1.14 [deg] in the binocular design.

[0151] Based on the above, the absolute value of the change in convergence angle at position X-24mm on the lens is reduced in the binocular design compared to the baseline design. Similarly, the absolute value of the change in convergence angle at position X+24mm on the lens is also reduced in the binocular design compared to the baseline design. Therefore, compared to the baseline design, the binocular design achieves a distance perception closer to that of the naked eye.

[0152] Furthermore, when comparing the difference between the change in convergence angle at position X-24mm on the lens and the change in convergence angle at position X+24mm on the lens, the difference is reduced to 1.14deg in the binocular design compared to the baseline design's 1.41deg. Therefore, the binocular design reduces distortion in spatial recognition through binocular vision compared to the baseline design.

[0153] In the above embodiments, it is described that the spectacle lens processing system 1 has an optical shop 10 that orders spectacle lenses corresponding to prescriptions for customers (wearers) and a spectacle lens processing site 20 that accepts orders from the optical shop 10 and manufactures spectacle lenses, but is not limited to this example.

[0154] For example, orders to eyeglass lens manufacturing facility 20 can also be placed via data transmission through networks such as the Internet or fax machines. Furthermore, the orderers may include ophthalmologists and general consumers.

[0155] In the above embodiment, as an example, the difference in prism values ​​(quantities) between the two lenses is calculated based on the relationship between the spherical power (D) and the prisms of the peripheral portion of the lens for two types of lenses, D1 and D2, but this is not limited to this example.

[0156] For example, the difference in prism values ​​(quantities) between the two lenses can be calculated based on the relationship between the spherical power (D) and the prisms at the periphery of the lens for more than three types of lenses.

[0157] In the above embodiment, as an example, the case in which the lens that obtains the value (quantity) of the prism of the peripheral part of the lens corresponding to the spherical power S2 is changed from lens D1 to lens D2 is described, but it is not limited to this example.

[0158] For example, the value (quantity) of the prism at the periphery of the lens corresponding to the spherical power S1 can be changed, as can the value (quantity) of the prism at the periphery of the lens corresponding to both the spherical power S1 and the spherical power S2.

[0159] In the above embodiments, the design device 200 can also derive optimization targets in the following manner.

[0160] Set the design objective, adjusted by the optimization parameter (α) of the benchmark design, to T0.

[0161] Let TR be the design objective adjusted by the optimization parameter (α) of the right eye lens, and TL be the design objective adjusted by the optimization parameter (α) of the left eye lens. In this case, equations (1) and (2) hold true.

[0162] TR=T0+dt1 (1)

[0163] TL=T0+dt2 (2)

[0164] The acquisition unit 204 acquires information determining the value (quantity) of the right prism at a position 5 mm or more but less than 50 mm from the optical center of the lens. Preferably, the acquisition unit 204 acquires information determining the value (quantity) of the right prism at a position 5 mm or more but less than 50 mm from the optical center of the lens in the horizontal direction. More preferably, the acquisition unit 204 acquires information determining the value (quantity) of the right prism at a position 10 mm or more but less than 30 mm from the optical center of the lens in the horizontal direction.

[0165] The acquisition unit 204 acquires information determining the value (quantity) of the left prism at a position 5 mm or more but less than 50 mm from the optical center of the lens. Preferably, the acquisition unit 204 acquires information determining the value (quantity) of the left prism at a position 5 mm or more but less than 50 mm from the optical center of the lens in the horizontal direction. More preferably, the acquisition unit 204 acquires information determining the value (quantity) of the left prism at a position 10 mm or more but less than 30 mm from the optical center of the lens in the horizontal direction.

[0166] The calculation unit 205 obtains information from the acquisition unit 204 regarding the value (quantity) of the right prism and the value (quantity) of the left prism. Based on the obtained information regarding the value (quantity) of the right prism and the value (quantity) of the left prism, the calculation unit 205 calculates the difference between the value (quantity) of the right prism and the value (quantity) of the left prism.

[0167] The modification unit 206 obtains information about the difference between the value (quantity) of the right prism and the value (quantity) of the left prism calculated by the determination calculation unit 205. Based on the obtained information about the difference between the value (quantity) of the right prism and the value (quantity) of the left prism, the modification unit 206 calculates the values ​​of dt1 and dt2 in a manner that reduces the difference.

[0168] The modification unit 206 can also set one of the values ​​of dt1 and dt2 to 0, and change the optimization parameter (α) of the design objective for the non-zero value of dt1 and dt2. Alternatively, the modification unit 206 can also change the optimization parameter (α) of the design objectives for both dt1 and dt2.

[0169] In the design device 200, the calculation unit 205 may pre-calculate the values ​​of dt1 and dt2, and the modification unit 206 may adjust the design target based on the pre-calculated values ​​of dt1 and dt2 to optimize the lens. Alternatively, the modification unit 206 may also incorporate the process of minimizing the difference in prism values ​​(quantities) during lens optimization into the lens optimization design.

[0170] However, if only the prism values ​​(quantities) are kept consistent, the aberrations of the lenses may increase. Therefore, it is also possible to set constraints on the design objectives.

[0171] Figure 15 This is a diagram illustrating another example of a lens design implemented by the design device involved in this embodiment. Figure 15 In the diagram, the horizontal axis represents the optimization parameter (α), and the vertical axis represents the spherical degree error and astigmatism. The spherical degree error is represented by a solid line, and the astigmatism is represented by a dashed line.

[0172] according to Figure 15It can be seen that as the spherical degree error decreases, astigmatism increases, and as the spherical degree error increases, astigmatism decreases.

[0173] Assume that the design objective of achieving zero spherical degree error is set as TS, and the design objective of achieving zero astigmatism is set as TA. Modification unit 206 sets TA≤T0≤TS. Modification unit 206 restricts the values ​​of dt1 and dt2 to ensure that TR and TL conform to TA≤TR and TL≤TS.

[0174] To improve visual appeal, the scope of the design objective can be further narrowed. For example, the change part 206 can also be set as TA+α≤TR, TL≤TS-β.

[0175] In the above embodiments, the design device 200 may utilize the difference in prism values ​​(amounts) of the lenses in the design of lenses for both eyes, and also utilize the actual spatial distortion in the optimized design of the lenses. Alternatively, the design device 200 may utilize the actual spatial distortion in the optimized design of the lenses, instead of utilizing the difference in prism values ​​(amounts) of the lenses in the design of lenses for both eyes.

[0176] When utilizing the distortion of actual space in the optimized design of lenses, the design device 200 sets a group of object points P in space. P is a set of points on a sphere or plane at a certain distance from the eye. The design device 200 can also vary the spacing between points, the range of points, and the distance between the points in the set of points according to the product.

[0177] Figure 16 This is a diagram illustrating another example of a lens design implemented by the design device involved in this embodiment. Figure 16 In the diagram, the left figure (1) illustrates the optimization of lenses for astigmatism prescriptions, and the right figure (2) illustrates the optimization of lenses that match the lens shape. Figure 16 In the diagram, the outer frame represents the optimized sheet shape, the center of the dashed line represents the optical center, and the dashed lines represent the various axes being optimized.

[0178] When optimizing a lens to match an astigmatism prescription, or when optimizing a lens to match its shape, the design device 200 optimizes multiple axes that connect the optical center and the outer frame at specific angles. For each axis, similar to the design device for spherical lenses, the design device 200 calculates the difference in prism values ​​(quantities) between the two eyes, and based on this calculated difference, modifies the design parameter (α) for each axis. This configuration reduces the difference in prism values ​​(quantities) between the two eyes.

[0179] The design device 200 calculates the light rays passing through the lens from the pupils of both eyes or the cycloid point of the eyeball and connecting to each point P. Based on the calculation results of the light rays connecting each point P, the design device 200 calculates the intersection point of the light rays from the eye at each object point. Based on the calculation results of the intersection point of the light rays from the eye, the design device 200 uses the difference in symmetry between the left and right sides of the intersection point to generate a distortion evaluation index.

[0180] The design device 200 can also incorporate this distortion evaluation index during the optimization process of the aspherical surfaces of the lenses for both eyes. When the distortion evaluation index is incorporated, the design device 200, similar to the above-described embodiment, optimizes by changing the optimization objective while minimizing spatial distortion using the distortion evaluation index.

[0181] This design allows for a binocular design that minimizes distortion within a distance and field of vision appropriate to the intended use of the glasses.

[0182] According to the design device 200 of the embodiment, when the prescriptions for the two eyes are different, compared with the reference design, the difference in the prism value (amount) of the lenses of the two eyes at the peripheral portion of the lens is reduced, thereby reducing the distortion of spatial vision through the eyes.

[0183] This configuration reduces distortion when observing the periphery using binocular vision compared to the baseline design. Furthermore, it reduces the difference in prism values ​​(magnifications) between the two eyes, thus reducing the magnification and aberration of the image at the periphery of the lens compared to the baseline design.

[0184] It is known that during binocular vision, a large difference in image magnification between the two eyes results in unequal images, diminishing the effectiveness of binocular vision. By designing device 200, compared to a baseline design, the difference in image magnification between the two eyes for peripheral vision can be reduced, thus facilitating binocular image fusion.

[0185] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the specific structure is not limited to these embodiments and may include designs that do not depart from the spirit of the present invention.

[0186] Label Explanation

[0187] 1…Spectacle lens processing system; 10…Optical store; 100…Store terminal device; 200…Design device; 202…Communication department; 203…Processing department; 204…Acquisition department; 205…Computing department; 206…Change department; 207…Production department; 210…Storage department; 300…Processing equipment

Claims

1. An eyeglass lens design device that designs a pair of aspherical lenses, the pair of aspherical lenses having different degrees of the left and right eyes, and the pair of aspherical lenses having rotational symmetry or axial symmetry in a part of a single vision lens or a single vision lens of a progressive addition lens for a far vision prescription, wherein the eyeglass lens design device includes: an acquisition unit that acquires information that specifies a left prism amount corresponding to a degree of the left eye and information that specifies a right prism amount corresponding to a degree of the right eye, based on a relationship between a prescribed degree of each of a plurality of aspherical lenses and a prism amount; a calculation unit that calculates an operation value of the left prism amount and the right prism amount, which is a difference between the left prism amount and the right prism amount, based on the information that specifies the left prism amount and the information that specifies the right prism amount acquired by the acquisition unit; and a change unit that derives an amount of change in a design parameter of one or both of the aspherical lens for the right eye and the aspherical lens for the left eye, based on the operation value of the left prism amount and the right prism amount calculated by the calculation unit, and changes the design parameter of one or both of the aspherical lens for the right eye and the aspherical lens for the left eye based on the derived amount of change in the design parameter, the design parameter being a parameter that changes a ratio of a spherical power error and a coma as a design target and a prism amount of a lens peripheral portion, in a case where the design parameter is set as a, a position with respect to a radius direction on an axis is set as r, the spherical power error is set as ΔP(r), and the coma is set as ΔC(r), an error function E(r, a) of an optimization target that minimizes |ΔP(r)| and |ΔC(r)| by a value of the design parameter is represented by the following expression: E(r, a) = a x |ΔP(r)| + (1 - a) x |ΔC(r)|.

2. The eyeglass lens design device according to claim 1, wherein the change unit derives an amount of change in a design parameter in which the difference between the left prism amount and the right prism amount is smaller, based on the difference between the left prism amount and the right prism amount.

3. The eyeglass lens design device according to claim 1 or 2, wherein the change unit changes the derived design parameter based on a limit value of a design parameter.

4. The eyeglass lens design device according to claim 1 or 2, wherein the acquisition unit acquires information that specifies a left prism amount at a position of 5 mm or more and 50 mm or less from an optical center and information that specifies a right prism amount corresponding to a degree of the right eye.

5. The eyeglass lens design device according to claim 1 or 2, wherein the acquisition unit acquires information that specifies a left prism amount at a position of 5 mm or more and 50 mm or less from an optical center in a horizontal direction and information that specifies a right prism amount corresponding to a degree of the right eye.

6. An eyeglass lens design method that is executed by a computer, the eyeglass lens design method designing a pair of aspherical lenses, the pair of aspherical lenses having different degrees of the left and right eyes, and the pair of aspherical lenses having rotational symmetry or axial symmetry in a part of a single vision lens or a single vision lens of a progressive addition lens for a far vision prescription, wherein ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The design method of the spectacle lens has the following steps: obtaining information for determining a left prism amount corresponding to the degree of the left eye and information for determining a right prism amount corresponding to the degree of the right eye based on a relationship between the prescription degree and the prism amount of each of a plurality of aspherical lenses; calculating an operation value of the left prism amount and the right prism amount, which is a difference between the left prism amount and the right prism amount, based on the information for determining the left prism amount and the information for determining the right prism amount obtained in the step of obtaining; and deriving an amount of change in a design parameter of one or both of the aspherical lens for the right eye and the aspherical lens for the left eye based on the operation value of the left prism amount and the right prism amount calculated in the step of calculating, and changing the design parameter of one or both of the aspherical lens for the right eye and the aspherical lens for the left eye based on the derived amount of change in the design parameter, the design parameter being a parameter for changing a ratio of a spherical degree error and a coma as a design target and a prism amount of a peripheral portion of a lens, when the design parameter is set as α, a position with respect to a radial direction on an axis is set as r, the spherical degree error is set as ΔP(r), and the coma is set as ΔC(r), an error function E(r,α) of an optimization target for minimizing |ΔP(r)| and |ΔC(r)| by a value of the design parameter is represented by the following expression: E(r,α) = α × |ΔP(r)| + (1 - α) |ΔC(r)|.

7. A computer program product including a computer program that causes a computer to execute the following steps: obtaining information for determining a left prism amount corresponding to the degree of the left eye and information for determining a right prism amount corresponding to the degree of the right eye based on a relationship between the prescription degree and the prism amount of each of a plurality of aspherical lenses having rotational symmetry or axial symmetry in a part of a single-vision lens for a distance or a single-vision lens for a distance of a progressive addition lens; calculating an operation value of the left prism amount and the right prism amount, which is a difference between the left prism amount and the right prism amount, based on the information for determining the left prism amount and the information for determining the right prism amount obtained in the step of obtaining; and deriving an amount of change in a design parameter of one or both of the aspherical lens for the right eye and the aspherical lens for the left eye based on the operation value of the left prism amount and the right prism amount calculated in the step of calculating, and changing the design parameter of one or both of the aspherical lens for the right eye and the aspherical lens for the left eye based on the derived amount of change in the design parameter, the design parameter being a parameter for changing a ratio of a spherical degree error and a coma as a design target and a prism amount of a peripheral portion of a lens, when the design parameter is set as α, a position with respect to a radial direction on an axis is set as r, the spherical degree error is set as ΔP(r), and the coma is set as ΔC(r), an error function E(r,α) of an optimization target for minimizing |ΔP(r)| and |ΔC(r)| by a value of the design parameter is represented by the following expression: E(r, a) = a x |AP(r)| + (1 - a) |AC(r)|.

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