Method for designing eyeglass lenses, method for manufacturing eyeglass lenses, and method for measuring visual acuity values

Abstract

To provide techniques of enabling spectacle lens design to reflect subjective responses of a subject in multiple states of the subject made to look downward.SOLUTION: A design method for spectacle lenses comprises: a step of setting multiple states of a subject wearing an optometry lens frame and made to look downward, causing the subject to compare the appearance of optotypes so as to obtain subjective responses of the subject; and a step of designing spectacle lenses suitable for the subject on the basis of the subjective responses.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for designing a spectacle lens, a method for manufacturing a spectacle lens, and a method for measuring visual acuity-related values. [Background technology]

[0002] Typically, to prepare a prescription for eyeglasses, a subject's refractive power is tested subjectively while wearing an eye test lens frame. The eye test lens frame has a lens holder, and a number of eye test lenses with different characteristics are sequentially fitted into the lens holder frame to determine the appropriate eyeglass prescription for the subject.

[0003] As an example of such a lens frame for eye examinations, Patent Document 1 discloses a lens frame that includes a pair of lens holding devices and temples attached to each lens holding device, with a rotation means provided between the lens holding devices and the temple ends for adjusting the inclination of the temple ends. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-104544 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of one embodiment of the present invention is to provide a technology that can reflect the subjective responses of a subject in a plurality of states in which the subject looks downward in the design of eyeglass lenses. [Means for solving the problem]

[0006] A first aspect of the present invention is A step of setting a plurality of states in which a subject wearing an optometric lens frame looks downward, having the subject compare how the visual target appears, and obtaining a subjective response from the subject; designing spectacle lenses suitable for the subject based on the subjective responses; The present invention relates to a method for designing a spectacle lens, comprising:

[0007] A second aspect of the present invention is In the step of obtaining the subjective response, the method for designing eyeglass lenses according to the first aspect sets the plurality of conditions using a plurality of trial lenses selected to simulate an aspherical design.

[0008] A third aspect of the present invention is In the step of obtaining the subjective response, the plurality of states are set using a plurality of trial lenses having different spherical powers with respect to a known addition power; In the method for designing a spectacle lens according to the first aspect, the step of designing the spectacle lens corrects the power of the near side portion.

[0009] A fourth aspect of the present invention is In the method for designing a spectacle lens according to the first aspect, in the step of obtaining the subjective response, the plurality of states are set using a plurality of trial lenses with different prism amounts.

[0010] A fifth aspect of the present invention is In the step of obtaining the subjective response, the plurality of states are set, each having a different angle of eye rotation; In the method for designing a spectacle lens according to the first aspect, an addition curve is corrected in the step of designing the spectacle lens.

[0011] A sixth aspect of the present invention is In the step of obtaining the subjective response, a lens frame for ophthalmology is used, which is configured so that the line of sight of the subject when the subject looks downward coincides with the optical axis of the trial lens. This is the method for designing eyeglass lenses according to any one of the first to fifth aspects.

[0012] A seventh aspect of the present invention is The method for designing eyeglass lenses according to the sixth aspect, wherein the trial lens frame is configured so that the distance from a reference point on the back surface of the trial lens to the corneal vertex of the subject remains constant when the angle of eyeball rotation is changed.

[0013] An eighth aspect of the present invention is A step of having a subject wearing an optometric lens frame look downward in a plurality of states and comparing how the subject sees the visual target, and obtaining a subjective response from the subject; designing spectacle lenses suitable for the subject based on the subjective responses; The method for manufacturing a spectacle lens includes the steps of:

[0014] A ninth aspect of the present invention is a method for manufacturing a semiconductor device comprising: This is a method for measuring visual acuity values, which includes a step of having a subject wearing an eye examination lens frame look downward in a number of positions, comparing how the subject sees an optotype, and obtaining the subject's subjective response. [Effects of the Invention]

[0015] According to one embodiment of the present invention, the subjective responses of a subject in a plurality of states in which the subject is made to look downward can be reflected in the design of eyeglass lenses. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a flowchart showing an example of a method for designing a spectacle lens according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing a state in which a numerical value relating to vision is measured in the step S100 of measuring a numerical value relating to vision when looking downward according to the first embodiment of the present invention. [Figure 3] FIG. 3 is a perspective view showing a lens frame for optometry according to the first embodiment of the present invention. [Figure 4] FIG. 4 is a front view showing a lens frame for optometry according to the first embodiment of the present invention. [Figure 5] FIG. 5 is a side view showing a lens frame for optometry according to the first embodiment of the present invention. [Figure 6] FIG. 6 is a side view showing a state in which a lens frame according to the first embodiment of the present invention is worn by a subject. [Figure 7] FIG. 7 is a diagram showing how the lens frame according to the first embodiment of the present invention is adjusted so that the rotation center of the angle-adjustable connection part coincides with the rotation center point. [Figure 8] FIG. 8 is a diagram showing how the front temple part is rotated downward by the angle-adjustable connector according to the first embodiment of the present invention. [Figure 9] FIG. 9(a) is a graph showing the results of a power simulation according to Example 1 of the present invention, and FIG. 9(b) is a graph showing the average power error and astigmatism according to Example 1 of the present invention. [Figure 10] FIG. 10(a) is a graph showing an aspheric design that emphasizes average power error according to Example 1 of the present invention, and FIG. 10(b) is a graph showing an aspheric design that emphasizes astigmatism according to Example 1 of the present invention. [Figure 11] FIG. 11(a) is a diagram showing a frequency distribution before correction according to Example 3 of the present invention, and FIG. 11(b) is a diagram showing a frequency distribution after correction according to Example 3 of the present invention. [Figure 12] FIG. 12 is a graph showing an addition curve according to Example 5 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] <Insights gained by the inventor> First, the inventor's findings will be explained. When determining a subject's eyeglass prescription, it is common to subjectively measure visual acuity using trial lenses. Most of these measurements are performed while the subject is looking straight ahead. However, examples of lenses in which the subject's gaze is directed in a direction different from straight ahead include progressive power lenses, which require the subject to rotate the eyeball to view multiple distances, from far to intermediate and near, and single-vision lenses, which may produce different visual outcomes between the periphery and the center. Note that in this specification, "eye examination" refers to a method of measuring visual values, a series of operations in which the subject visually recognizes a target and determines the subject's refractive index, prism value, and other parameters based on their subjective responses.

[0018] Whether intentional or not, when humans look at an object below, they not only turn their head but also look down to some extent, accompanied by downward rotation of the eyes, to view the object. However, there are very few cases where such a state is realized, a subjective response is obtained, and this is reflected in the design of eyeglass lenses.

[0019] The inventors of the present invention have conducted extensive research into the above-mentioned problems. As a result, they have found that by having a subject gaze downward in multiple conditions and obtaining the subject's subjective responses, it is possible to design eyeglass lenses that are more suitable for the subject. This makes it possible to design eyeglass lenses that take into account optically occurring (off-axis) aberrations and prism effects when measuring the power required to create eyeglass lenses. It is also possible to address the possibility that physiological differences in vision occur between looking straight ahead and looking downward, depending on the direction of gaze and downward eye movement.

[0020] [Details of the embodiment of the present invention] Next, an embodiment of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0021] The ophthalmic trial lenses (hereinafter also referred to as ophthalmic trial lenses) mentioned in this specification have an object-side surface and an eyeball-side surface. The "object-side surface" is the surface that faces the object when a subject wears an ophthalmic trial lens frame equipped with the ophthalmic trial lens, and is also called the "front surface." The "eyeball-side surface" is the opposite, i.e., the surface that faces the eye when a subject wears an ophthalmic trial lens frame equipped with the ophthalmic trial lens, and is also called the "back surface." This relationship also applies to spectacle lenses and the lens substrate that forms the basis of spectacle lenses. In other words, spectacle lenses and lens substrates also have an object-side surface and an eyeball-side surface.

[0022] In this specification, downward gaze refers to a state in which the eyes are rotated downward (including downward right and downward left) in a state other than straight ahead (first eye position), achieving single binocular vision. In the following embodiment, we will particularly describe a case in which the eyeball rotation angle in downward gaze (the angle at which the eyeball is rotated vertically downward from the straight ahead state) is between 10 degrees and 40 degrees.

[0023] <First embodiment of the present invention> (1) Design method for eyeglass lenses First, a method for designing a spectacle lens according to this embodiment will be described. Fig. 1 is a flowchart showing an example of the method for designing a spectacle lens according to this embodiment. As shown in Fig. 1, the method for designing a spectacle lens according to this embodiment includes, for example, a step S100 for measuring numerical values ​​related to vision in downward gaze, and a design step S110. The step S100 for measuring numerical values ​​related to vision in downward gaze includes, for example, an aspheric correction test S101, a near lateral power correction test S102, a prism thinning correction test S103, and an addition curve correction test S104.

[0024] (Step S100 for measuring numerical values ​​related to downward gaze) The step S100 for measuring numerical values ​​related to downward gaze is, for example, a step of setting a plurality of states in which a subject wearing an eye examination lens frame looks downward, having the subject compare how the visual target appears, and obtaining the subject's subjective response. As shown in Fig. 1, the step S100 for measuring numerical values ​​related to downward gaze includes a plurality of tests, but it is not necessary to perform all of the tests; at least one of the tests may be performed as needed.

[0025] In the step S100 for measuring numerical values ​​related to visual acuity in downward gaze, it is preferable to use an optometric lens frame configured so that the line of sight of the subject when looking downward coincides with the optical axis of the trial lens. FIG. 2 is a diagram showing the state of measuring numerical values ​​related to visual acuity in downward gaze in the step S100 for measuring numerical values ​​related to visual acuity in downward gaze. As shown in FIG. 2, when measuring numerical values ​​related to visual acuity in downward gaze, the subject directs their line of sight S downward by a predetermined angle relative to the horizontal. At this time, the trial lens L is rotated around the center of rotation O by the same angle as the rotation angle of the eyeball E while maintaining the distance r between the reference point CL on the back surface of the trial lens and the center of rotation O. This distance r can be calculated as the sum of the distance VC from the reference point CL on the back surface of the trial lens to the vertex of the cornea C of the subject's eyeball E and the distance CR from the vertex of the cornea C to the center of rotation O of the eyeball E. As a result, the distance from the reference point CL on the back surface of the trial lens L to the vertex of the cornea C becomes equal to the distance VC in horizontal gaze. In addition, the line of sight S coincides with the optical axis XL of the ophthalmic lens L. This allows for highly accurate measurements without blurring or prism caused by aberration.

[0026] Furthermore, in the step S100 of measuring the numerical values ​​related to the visual acuity in downward gaze, it is preferable to use an optometric lens frame that is configured so that the distance from the reference point on the back surface of the trial lens to the corneal vertex of the subject is constant when the angle of rotation of the eyeball is changed, for example. This allows the center of rotation of the eyeball to coincide with the center of rotation of the optometric lens frame, thereby enabling more accurate measurements.

[0027] The specific configuration of the above-mentioned lens frame for eye examination will be explained in detail in (2) Configuration of the lens frame for eye examination. Also, the method of using the lens frame for eye examination and the method of presenting the visual target will be explained in detail in (3) How to use the lens frame for eye examination.

[0028] (Design process S110) The design step S110 is a step of designing a spectacle lens suitable for the subject based on the subject's subjective response obtained in the measurement step S100 of numerical values ​​related to downward visual acuity. The type of spectacle lens designed in the design step S110 is not particularly limited, and may be a single-vision lens or a progressive-power lens.

[0029] In the design step S110, it is preferable to correct various characteristics of the spectacle lens (for example, the amount of asphericity and the amount of prism thinning) according to the test performed in the measurement step S100 of numerical values ​​related to visual acuity in downward gaze. This makes it possible to reflect differences in vision due to downward gaze in the design of the spectacle lens, and to design spectacle lenses that are more suitable for the subject. Below, we will explain each test performed in the measurement step S100 of numerical values ​​related to visual acuity in downward gaze and each correction performed in the design step S110.

[0030] (Aspherical correction test S101) Generally, in a minus spherical lens, the power in the meridian direction is stronger than the power in the circumferential direction, so when looking downward, the image is equivalent to looking through a lens in which the absolute value of the refractive power in both principal meridians is greater in the 90-degree direction than in the 180-degree direction. When aspheric correction is performed on such lenses, a method is used to minimize either the power error or astigmatism, or an index that balances them. However, the perception of blur varies from person to person, and the perception also varies depending on the index used. According to the eyeglass lens design method of this embodiment, the perception of blur when the subject looks downward can be reflected in the aspheric design of the eyeglass lens.

[0031] In the aspheric correction test S101, it is preferable to use multiple trial lenses selected to simulate multiple aspheric designs, set multiple conditions in which the subject looks downward, have the subject compare how the visual target appears, and obtain the subject's subjective response. Specifically, for example, while the subject looks downward, astigmatism in the directions of 90 degrees and 180 degrees of the astigmatic axis is added to the prescription power corrected in frontal vision, and the subject compares how the visual target appears, and obtain the subject's subjective response. This allows the aspheric amount appropriate for the subject to be designed.

[0032] When an aspheric correction test S101 is performed in the measurement step S100 of numerical values ​​related to visual acuity in downward gaze, it is preferable to correct, for example, the aspheric amount of the spectacle lens in the design step S110. Specifically, for example, if astigmatic addition with an astigmatic axis of 90 degrees is preferred, it is preferable to increase the aspheric amount (i.e., to minimize astigmatism), and if astigmatic addition with an astigmatic axis of 180 degrees is preferred, it is preferable to decrease the aspheric amount (i.e., to minimize power error). This makes it possible to design spectacle lenses that provide the subject with a more comfortable wearing experience.

[0033] (Near lateral power correction test S102) Generally, the add power of a progressive power lens is determined from the prescription powers for distance and near vision corrected in straight-on vision. However, with progressive power lenses, the influence of the eyelids and eye muscles is different when looking downward than when looking straight on. Therefore, when measuring the power in near downward vision, it is possible that the subject may experience hyperopia or myopia compared to straight-on vision. According to the spectacle lens design method of this embodiment, the difference in vision when the subject looks downward near vision can be reflected in the near side power of the progressive power lens.

[0034] In the near side power correction test S102, it is preferable to use multiple trial lenses with different spherical powers for a known addition power, set multiple conditions in which the subject looks downward, have the subject compare how the optotype appears, and obtain the subject's subjective response. This makes it possible to design near side powers that are appropriate for the subject.

[0035] When the near-side power correction test S102 is performed in the measurement step S100 of the numerical values ​​related to the visual acuity in downward gaze, it is preferable to correct the power of the near-side portion in the design step S110, for example, while maintaining the known addition power. Specifically, for example, if a spherical power greater than the known addition power is preferred, it is preferable to make the power change in the horizontal direction from the near measurement point more gradual than usual (i.e., increase the near-side power). Also, if a spherical power smaller than the known addition power is preferred, it is preferable to make the power change in the horizontal direction from the near measurement point more rapid than usual (i.e., decrease the near-side power). This makes it possible to improve the wearing comfort during near downward gaze while maintaining the basic design of the progressive power lens.

[0036] (Prism Thinning Correction Test S103) Prism thinning is used in many progressive addition lenses to eliminate or adjust unevenness in the lens's vertical thickness. Generally, the maximum prism thinning amount is set to maximize the uniformity of the edge thickness, depending on the addition power, etc. Since most of these prisms are base-down prisms, optical effects such as the ground appearing to be elevated or the perception of distance below are altered. According to the spectacle lens design method of this embodiment, the difference in vision when the subject looks downward can be reflected in the prism thinning amount of the progressive addition lens. Furthermore, by using an optometric lens frame configured so that the subject's line of sight when looking downward coincides with the optical axis of the optometric lens, the prism effect of off-axis light does not need to be considered, allowing for more accurate measurements.

[0037] In the prism-thinning correction test S103, it is preferable to use multiple trial lenses with different prism amounts, set multiple conditions in which the subject looks downward, have the subject compare how the target appears, and obtain the subject's subjective response. This allows the amount of prism thinning that is appropriate for the subject to be designed.

[0038] If the prism-thinning correction test S103 is performed in the measurement step S100 of the numerical values ​​related to downward gaze vision, it is preferable to correct the amount of prism-thinning of the progressive-power lens, for example, in the design step S110. This can improve the wearing comfort of the progressive-power lens.

[0039] (Addition curve correction test S104) For example, when checking the vision of a lens at an angle of downward eyeball rotation estimated from the progressive zone length (hereinafter also referred to as the estimated eyeball rotation angle), if a subject still experiences blurred or distorted images even when using an optometric lens frame configured to suppress the effects of off-axis aberrations of the lens, it is highly likely that this is due to personal physiological factors unrelated to the lens. According to the spectacle lens design method of this embodiment, the difference in vision when the subject looks downward can be reflected in the addition curve of the progressive power lens. Furthermore, by using an optometric lens frame configured so that the subject's line of sight when looking downward coincides with the optical axis of the trial lens, the effects of off-axis aberrations of the trial lens can be eliminated, allowing the subject to personally feel the change in vision due to the effects of eyeball rotation.

[0040] In the addition power curve correction test S104, it is preferable to set a plurality of states in which the subject looks downward so as to change the angle of eyeball rotation, have the subject compare how the target appears, and obtain the subject's subjective response. Specifically, for example, the subject may compare how the target appears at an estimated eyeball rotation angle with a shallower eyeball rotation angle, and obtain the subject's subjective response. This allows the design of an addition power curve suited to the subject.

[0041] When the addition power curve correction test S104 is performed in the measurement step S100 of the numerical values ​​related to the visual acuity in downward gaze, it is preferable to correct the addition power curve of the progressive power lens in the design step S110, for example. Specifically, for example, if a shallower eyeball rotation angle than the eyeball rotation angle based on the addition power curve is preferred, it is preferable to correct the addition power curve (for example, shorten the progressive power corridor length) by increasing the rate of increase (slope) of the addition power curve so that the desired addition power is reached at a stage where the eyeball requires less distance movement. Also, if a deeper eyeball rotation angle than the eyeball rotation angle based on the addition power curve is preferred, it is preferable to correct the addition power curve (for example, lengthen the progressive power corridor length) by decreasing the rate of increase (slope) of the addition power curve so that the eyeball requires more distance movement to reach the desired addition power. This can improve the wearing comfort of the progressive power lens.

[0042] Through the above steps, the subjective responses of the subject in a plurality of states of downward gaze can be reflected in the design of the eyeglass lens, thereby enabling the design of an eyeglass lens suited to the subject. The present invention can also be applied as a method for measuring numerical values ​​related to vision. In this case, the step S100 of measuring numerical values ​​related to vision in downward gaze may be performed, and the design step S110 may be omitted. The present invention can also be applied as a method for manufacturing eyeglass lenses. In this case, eyeglass lenses may be manufactured through the above-described steps. Steps other than those described in this specification may be realized using known technology.

[0043] (2) Configuration of lens frames for eye examinations Next, the configuration of the lens frame for optometry according to this embodiment (hereinafter simply referred to as the lens frame) will be described with reference to the drawings. The lens frame according to this embodiment is a lens frame that can be suitably used in the measurement step S100 of the numerical values ​​related to downward gaze vision.

[0044] 3 to 5 show the lens frame of this embodiment, with Fig. 3 being a perspective view, Fig. 4 being a front view, and Fig. 5 being a side view. As shown in Figs. 3 to 5, the lens frame 1 of this embodiment includes a frame main body 10 and a lens holding member 20.

[0045] The frame body 10 has a pair of temple members 30 and a nose rest frame 40. Each temple member 30 includes a front temple portion 32, a rear temple portion 34, and an angle-adjustable connection portion 36 that rotatably connects the front temple portion 32 to the rear temple portion 34.

[0046] The rear temple portion 34 has a shape in which the front portion extends linearly in the front-to-rear direction and the rear end portion curves downward. The rear temple portion 34 includes a first rear temple member 340 located in the front and a second rear temple member 342 located in the rear.

[0047] The first rear temple member 340 has a hollow rectangular cross section and extends linearly. The second rear temple member 342 has a hollow rectangular cross section and is formed with a curved portion 342A that curves downward at the rear end. This curved portion 342A of the second rear temple member 342 functions as an earmuff when the subject wears the lens frame 1.

[0048] The width and height of the inner surface of the cross section of the second rear temple member 342 are substantially equal to the width and height of the outer surface of the cross section of the first rear temple member 340. The rear end of the first rear temple member 340 is nested within the front end of the second rear temple member 342. This nested structure allows the second rear temple member 342 to move in the front-rear direction relative to the first rear temple member 340. In other words, this nested structure functions as a length adjustment mechanism 344 for adjusting the length of the rear temple portion 34. Note that the configuration of the length adjustment mechanism for the rear temple portion is not limited to a nested structure, and any appropriate configuration for adjusting and maintaining the length may be employed, such as a configuration in which a slit is formed in one of the first rear temple member 340 and the second rear temple member 342, and a protrusion is formed in the second rear temple member 342 that is slidable within the slit. The cross-sectional shape of the first rear temple member 340 and the second rear temple member 342 is not limited to a rectangle, and any other suitable shape such as a circle may be adopted.

[0049] The front temple portion 32 has a shape that extends linearly toward the front and includes a first front temple member 320 located in the front and a second front temple member 322 located in the rear.

[0050] The first front temple member 320 has a hollow rectangular cross section and extends linearly. The second front temple member 322 has a hollow rectangular cross section and extends linearly. The width and height of the inner surface of the cross section of the second front temple member 322 are approximately equal to the width and height of the outer surface of the cross section of the second front temple member 322. The rear end of the first front temple member 320 is nested within the front end of the second front temple member 322. This nested structure allows the second front temple member 322 to move in the front-rear direction relative to the first front temple member 320. In other words, this nested structure functions as a length adjustment mechanism 324 for adjusting the length of the front temple member 32. The length adjustment mechanism 324 of the front temple member 32 can be configured appropriately, similar to the length adjustment mechanism 344 of the rear temple member 34. The cross-sectional shapes of the first front temple member 320 and the second front temple member 322 are not limited to rectangular, and can be any appropriate shape, such as circular.

[0051] The angle-adjustable connection part 36 rotatably connects the front temple part 32 and the nose rest frame 40 to the rear temple part 34. That is, the rotation center of the front temple part 32 and the nose rest frame 40 relative to the rear temple part 34 is located at the center of the angle-adjustable connection part 36. The angle-adjustable connection part 36 allows the front temple part 32 and the nose rest frame 40 to rotate relative to the rear temple part 34 within a plane defined by the up-down direction and the front-to-back direction, and can maintain the respective angles of the front temple part 32 and the nose rest frame 40 relative to the rear temple part 34 at desired angles. A ratchet mechanism or the like can be used as the mechanism for such an angle-adjustable connection part 36. Note that the mechanism for the angle-adjustable connection part 36 is not limited to a structure that allows for stepwise angle change like a ratchet mechanism, but may also be a structure that allows for continuous angle change.

[0052] The front temple part 32 can be rotated in directions that tilt the front upward and downward from a state parallel to the rear temple part 34. The range of angles within which the front temple part 32 can be rotated is preferably 60 degrees in both the vertical and horizontal directions, and more preferably 30 degrees in both the vertical and vertical directions.

[0053] The nose rest frame 40 has a pair of first frame members 400 extending forward from each angle-adjustable connection portion 36 in a horizontal view, a pair of second curved frame members 402 connected to the front of each first frame member 400, and a third horizontal frame member 404 spanning between the pair of second curved frame members.

[0054] The rear end of the first frame member 400 is connected to the angle-adjustable connection portion 36. The first frame member 400 has a hollow rectangular cross section and extends linearly. The second bending frame member 402 has a hollow rectangular cross section and is bent vertically between its base end and tip end. The width and height of the inner surface of the cross section of the second bending frame member 402 are approximately equal to the width and height of the outer surface of the cross section of the first frame member 400. The front end of the first frame member 400 is nested within the rear end of the second bending frame member 402. This nested structure allows the second bending frame member 402 to move in the front-to-rear direction relative to the first frame member 400. In other words, this nested structure functions as a length adjustment mechanism 410 for adjusting and maintaining the length of the nose rest frame 40 in the front-to-rear direction.

[0055] The third horizontal frame member 404 has a hollow rectangular cross section and extends linearly in the horizontal direction. The width and height of the outer cross section of the third horizontal frame member 404 are approximately equal to the width and height of the inner cross section of the second curved frame member 402. Both ends of the third horizontal frame member 404 are nested within the ends of the second curved frame member 402. This nested structure allows the second curved frame members 402 to move laterally relative to the third horizontal frame member 404, thereby freely changing the horizontal width of the nose rest frame 40. In other words, this nested structure functions as a width adjustment mechanism 420 for adjusting the horizontal width of the nose rest frame 40.

[0056] A pair of nose rest support parts 430 are attached symmetrically to the horizontal center of the nose rest frame 40. The nose rest support parts 430 are attached so as to extend downward from the center of the nose rest frame 40, and nose rests 432 are attached to their tips. When wearing the lens frame 1, the nose rests 432 of the nose rest support parts 430 are positioned so as to abut against both sides of the subject's nose. The nose rest support parts 430 may be made of an elastic material such as rubber, or may be made of a deformable resin.

[0057] The lens holding member 20 comprises a bridge member stretched across the front temple portions 32, connection portions 230 that connect both ends of the bridge member 200 to the front ends of the front temple portions 32, and a pair of lens frames 220 attached to the bridge member 200.

[0058] The bridge member 200 includes a pair of first flexure members 202 and a second cross member 204 disposed between the first flexure members 202 . The first bending member 202 has a vertical portion 202A that extends and has its upper end connected to the front end of the front temple portion 32 via a connecting portion 230, and a horizontal portion 202B that bends perpendicularly from the vertical portion 202A and extends laterally inward. The first bending member 202 has a hollow rectangular cross section.

[0059] The second horizontal member 204 has a hollow rectangular cross section and extends linearly in the horizontal direction. The width and height of the outer cross section of the second horizontal member 204 are approximately equal to the width and height of the inner cross section of the first bending member 202. Both ends of the second horizontal member 204 are nested within the ends of the first bending member 202. This nested structure allows the first bending member 202 to move laterally relative to the second horizontal member 204, thereby freely changing the horizontal width of the bridge member 200. In other words, this nested structure functions as a width adjustment mechanism 210 for adjusting and maintaining the horizontal width of the bridge member 200.

[0060] The connecting portion 230 connects the front end of the front temple portion 32 and the upper end of the vertical portion 202A of the first bending member 202 of the bridge member 200. The connecting portion 230 can be set to any height depending on the length of the vertical portion 202A of the first bending member 202 of the bridge member 200, but in this embodiment, it is located at the same height as the center of the trial lens attached to the lens frame 220. This allows the length of the front temple portion 32 to be more smoothly adjusted to a predetermined length using the length adjustment mechanism 324, as will be described later.

[0061] Each lens frame 220 includes a lens frame body 222 and a pillar portion 224 that supports the lens frame body 222. The lens frame body 222 is an arc-shaped member that is rigid enough to hold a trial lens, and grooves are formed on the top surface for mounting up to three trial lenses, such as a trial lens and trial lens.

[0062] The pillar portion 224 is cylindrical and extends downward from the lower end of the lens frame 220 . The lens frame 220 is attached to the upper surface of the horizontal portion 202B of the first bending member 202 of the bridge member 200. The bridge member 200 incorporates a lens spacing adjustment mechanism 212 that enables the lens frame 220 to move laterally along the horizontal portion 202B, as well as a warp angle adjustment mechanism 214 that enables the lens frame 220 to rotate around the central axis of the pillar portion 224.

[0063] The lens spacing adjustment mechanism 212 and the warp angle adjustment mechanism 214 may be configured, for example, such that a slit is formed in the horizontal portion 202B and the base of the pillar portion 224 is rotatably inserted into the slit, and by rotating the dial members 212 and 214, the spacing of the lens frames 220 (spacing of the trial lenses) and the angle of the lens frames 220 (angle of the trial lenses) can be changed.

[0064] It is desirable that the lateral movement of the lens frames 220 by the lens distance adjustment mechanism 212 is configured so that the pair of lens frames 220 moves symmetrically. Such a configuration can be adopted in which a threaded rod with threaded grooves formed symmetrically in the first bending member 202 and the second horizontal member is arranged, a nut that screws onto this threaded rod is attached to the lower end of the column portion 224, and the threaded rod is rotated.

[0065] (3) How to use the lens frame for eye examinations Next, a method of using the lens frame 1 will be described. First, the lens frame 1 is worn by a subject. FIG. 6 is a side view showing the lens frame according to this embodiment worn by the subject. As shown in FIG. 6, the lens frame 1 can be worn by the subject P by abutting the nose rests 432 of the nose rest support portion 430 on both sides of the subject P's nose N and placing the curved portions 342A of the pair of rear temple portions 34 over the subject P's ears EA. At this time, the width of the pair of temple members 30 is adjusted to fit the width of the subject P's face. The width of the pair of temple members 30 can be changed by adjusting the width of the bridge member 200 with the width adjustment mechanism 210 and adjusting the width of the nose rest frame 40 with the length adjustment mechanism 410. Furthermore, the lens frame 220 is moved laterally by the lens spacing adjustment mechanism 212 according to the subject's interpupillary distance PD so that the reference point of the lens frame 220 coincides with the center of the subject's pupils.

[0066] Next, as shown in Fig. 7, the lens frame 1 is adjusted so that the rotation center of the angle-adjustable connection part 36 coincides with the rotation center point O. Specifically, the length of the rear temple part 34 is adjusted using the length adjustment mechanism 344, and the length of the nose rest frame 40 is adjusted using the length adjustment mechanism 410, thereby adjusting the angle of the nose rest frame 40 relative to the rear temple part 34. This allows the position of the angle-adjustable connection part 36 of the lens frame to be moved within a vertical plane in the front-to-rear direction. Then, the rotation center axis of the angle-adjustable connection part 36 can be moved so that it coincides with the rotation center point O.

[0067] Furthermore, this adjustment work can be done only finely by adjusting the length of the rear temple portion 34, the length of the nose rest frame 40, and the angle of the nose rest frame 40 relative to the rear temple portion 34 in advance before wearing the lens frame 1.

[0068] In this way, by attaching the lens frame 1 and performing the adjustment work, the lens frame 1 can be attached to the face of the subject P so that the center of rotation of the angle-adjustable connection part 36 of the lens frame 1 is located to the side of the rotation center point O of the subject P.

[0069] Next, the trial lens L is attached to the lens frame 220. Up to three trial lenses L are attached to the lens frame 220. The trial lenses may be a combination of spherical lenses, cylindrical lenses, and prismatic lenses. The horizontal line HL is aligned with the optical axis XL of the trial lens L, and the position of the trial lens L is adjusted so that the distance from the reference point CL on the back surface of the trial lens L to the corneal vertex is VC. This results in the distance r = VC + CR from the reference point CL on the back surface of the trial lens to the center of rotation O. The position of the trial lens L can be adjusted by rotating the front temple portion 32 relative to the rear temple portion 34 around the angle-adjustable connecting portion 36 and adjusting the length of the front temple portion 32 using the length adjustment mechanism 324.

[0070] The optometry data for horizontal gaze may be measured before or after the step S100 for measuring the numerical values ​​related to the visual acuity in downward gaze. Specifically, a target T is presented at a viewing distance at which the subject requires spectacle lenses, for example, about 2 m in front of the subject, and the subject is asked to look at the target T in horizontal gaze through the optometry lenses. Then, the optometry lenses are replaced based on the subject's response, and the optometry data for horizontal gaze is measured while checking the visual acuity or wearing comfort.

[0071] Next, as shown in FIG. 8 , the front temple portion 32 is rotated downward by a specified angle, for example, 15 degrees, using the angle-adjustable connector 36. At this time, the lens frame 220 may be rotated so as to achieve a predetermined deflection angle. Then, optometry data for downward gaze is measured (step S100 for measuring numerical values ​​related to vision in downward gaze). Specifically, a visual target T is presented at a height approximately 2 m in front of the subject and 15 degrees below. The subject is then asked to look at the visual target T through the trial lenses while keeping their head still. Then, based on the subject's response, the trial lenses are replaced, visual acuity or wearing comfort is checked, and optometry data for downward gaze is measured.

[0072] At this time, by rotating the front temple part 32 downward by a predetermined angle around the angle-adjustable connection part 36 that coincides with the center of rotation O, the relative positions of the trial lens L and the subject's pupil can be made to remain the same as in the case of horizontal gaze. In other words, the subject's line of sight S coincides with the optical axis XL of the trial lens L, and the distance from the reference point CL on the back surface of the trial lens L to the corneal vertex is VC.

[0073] When measuring optometry data for downward gaze or horizontal gaze, the subject may be instructed to view a target at a specified angle in a natural posture while allowing the subject to move their head. The subject's head rotation angle at this time may be measured by processing image data, and the front temple 32 may be rotated downward using the angle-adjustable connector 36 by an angle equal to the difference between the specified angle and the head rotation angle. Even in this case, the subject's line of sight S coincides with the optical axis XL of the ophthalmic lens L, and the distance from the reference point CL on the back surface of the ophthalmic lens L to the corneal vertex is VC. The subject's head rotation angle can also be determined using a front or side image of the subject or a measuring device such as a gyro sensor.

[0074] The lens frame 1 of this embodiment can measure optometry data in both horizontal and downward gaze states. Therefore, for example, even when measuring optometry data in horizontal gaze before or after the step S100 for measuring numerical values ​​related to vision in downward gaze, there is no need to change the lens frame, and measurement can be performed smoothly.

[0075] <Other Embodiments of the Present Invention> Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments and can be modified in various ways without departing from the spirit of the present invention.

[0076] For example, in the above embodiment, the nose rest frame 40 is rotatable around the angle-adjustable connecting part 36 and its length is adjustable by the length adjustment mechanism 410, but the nose rest frame 40 does not necessarily have to be rotatable or its length adjustable. For example, by making the nose rest support part 430 a member that can support the lens frame 1 and is deformable, the rotation center of the front temple part 32 can be made freely movable in the front-rear and up-down directions. [Example]

[0077] Next, examples of the present invention will be described. These examples are merely examples of the present invention, and the present invention is not limited to these examples.

[0078] Example 1 In Example 1, a case will be described in which an aspheric correction test S101 is performed on a subject with a prescription of SPH (spherical power) -5.50 D, and a single-vision lens with a refractive index of 1.60 and a base curve of 1 is designed. In the following examples, for example, a state in which the angle of rotation of the eyeball in downward gaze is 30 degrees will also be simply referred to as downward gaze 30 degrees to avoid complexity.

[0079] First, we performed a power simulation for a spherical design and calculated the power distribution in the meridian and circumferential directions. The results are shown in Figure 9(a). From the average and difference of the powers shown in Figure 9(a), we calculated the mean power error and astigmatism. The results are shown in Figure 9(b). As shown in Figure 9(b), for example, at a downward gaze of 30 degrees, the mean power error was found to be 0.46D and the astigmatism was 0.75D. Aspheric design is used to reduce this error, but theoretically, it is impossible to simultaneously reduce the astigmatism and mean power error to zero. Therefore, to optimize the aspheric design, we conducted the aspheric correction test S101. We had the subjects compare the wearing experience of trial lenses (A) with SPH -5.25D, CYL (cylinder power) -0.25D, and AX (astigmatic axis) 180° at a downward gaze of 30 degrees, with trial lenses (B) with SPH -5.25D.

[0080] If the patient responds that (A) is good, then the aspheric design that prioritizes mean power error shown in Figure 10(a) should be applied, and if the patient responds that (B) is good, then the aspheric design that prioritizes astigmatism shown in Figure 10(b) should be applied. From the above, it was confirmed that it is possible to design a lens that is optimized for the state of the eye when looking downward.

[0081] In this embodiment, the optimization of the aspherical design for distance vision has been described as an example, but the power of the lens to be compared for the wearing comfort may be determined based on a simulation of the aspherical design performed while changing the target distance. Also, if a response is that a state close to the spherical design is preferable, aspherical design may not be performed. For example, if the best wearing comfort is obtained when wearing a test lens combined to achieve (C): SPH-5.50D, CYL-0.75D, and AX180 degrees, it may be determined that a design without adding an aspherical surface is optimal, and a lens design may be performed.

[0082] Example 2 In Example 2, as in Example 1, an aspheric correction test S101 is performed on a subject with a prescription of SPH-5.50D, and a single-vision lens with a refractive index of 1.60 and a base curve of 1 is designed. As a simpler method, a method focusing on changes in the amount of astigmatism will be described.

[0083] Adding a negative cylinder power to (A) in the AX90-degree direction cancels out the astigmatism, resulting in a wearing sensation closer to (B), while adding it in the AX180-degree direction increases the amount of astigmatism, resulting in a wearing sensation closer to (C). This change in wearing sensation is maintained even if (A) is used as the prescription value, but it is more preferable to keep the spherical equivalent power constant depending on the lens added. Therefore, an aspheric correction test S101 was conducted, and three conditions were compared: wearing an SPH-5.50D trial lens at a downward gaze angle of 30 degrees, and adding SPH+0.25D and CYL-0.50D lenses in the AX90-degree and AX180-degree directions, respectively.

[0084] In this case, subjects who answered that the AX90° or AX180° condition was best were assigned the astigmatism-weighted aspherical design and the spherical design, respectively, and subjects who answered that no addition was best were assigned the power-weighted aspherical design so that the prescribed power was achieved.From the above, as in Example 1, it was confirmed that a lens can be designed that is optimized for the eye condition when looking downward.In addition, since there is a continuous change between the spherical design and the power-weighted aspherical design, and between the power-weighted aspherical design and the astigmatism-weighted aspherical design, it is possible to change the weighting through multiple trials to achieve a more optimally balanced design.

[0085] Example 3 In the third embodiment, a case will be described in which a near side power correction test S102 is performed on a subject with an SPH of 0.00D and an Add (additional power) of 2.00D, and a progressive power lens is designed.

[0086] The subjects were asked to look downward at a near target (approximately 40 cm) while wearing SPH+2.00D and SPH+2.25D trial lenses, and the results showed that the SPH+2.25D vision was preferred. In this case, an example of an Add2.00D lens normally designed based on a prescription would have a power distribution as shown in FIG. 11(a). However, because the subject preferred a higher spherical power during downward rotation, a design with a more gradual change in power from the near measurement point to the horizontal direction, as shown in FIG. 11(b), could be used. As described above, progressive power lenses can be designed that take into account the effects of eye rotation. The design used in this example allows the power of the near lateral portion used for near downward gaze to be set stronger than in a normal design while maintaining the add power. This allows the lens to be worn closer to the vision selected by comparison using the trial lens frame, improving the wearing comfort during near downward gaze.

[0087] In this embodiment, the near lateral power correction test S102 is performed using one type of eyeball rotation angle in downward gaze. However, the eyeball rotation angle in downward gaze may be changed, and the subject's subjective response may be obtained for each eyeball rotation angle. In this case, for example, it is possible to correct the near lateral power to be stronger or weaker than the normal design for each eyeball rotation angle while maintaining the addition power.

[0088] Example 4 In the fourth embodiment, a case will be described in which the prism-thinning correction test S103 is performed and a progressive-power lens in which the amount of prism-thinning has been corrected is designed.

[0089] For a progressive power lens with a prescription of SPH-2.50D, Add 2.50D, and a progressive zone length of 11mm for both left and right eyes, the normal prism thinning amount is 1.00 prism DN. Therefore, a subject with the above prescription underwent the prism thinning correction test S103. They were asked to wear trial lenses with 1.00 prism DN and trial lenses with 0.50 prism DN at a downward gaze of 22 degrees, and the wearing experience was compared. The subjects responded that the 0.50 prism DN was better. Furthermore, when comparing the 0.50 prism DN with no prism, the subjects responded that there was no difference in wearing experience. In this case, a design with 0.50 prism DN should be applied. From the above, we confirmed that it is possible to design a lens that provides the best balance between thinness and visibility.

[0090] Example 5 In Example 5, a case will be described in which an addition power curve correction test S104 is performed on a subject with a prescription of SPH 0.00D and Add 2.00D, and the addition power curve of a progressive power lens is corrected.

[0091] First, the subjects were asked to confirm the wearing comfort with the lens power at +2.00D and at a downward gaze angle of 28 degrees. Then, the subjects were asked to compare the wearing comfort with a downward gaze angle of 22 degrees and a downward gaze angle of 28 degrees. If the subject responded that the downward gaze angle of 22 degrees was preferred, the addition power curve A shown in Figure 12 should be designed (i.e., the addition power curve should be corrected so that the progressive corridor length is shorter), and if the subject responded that the downward gaze angle of 28 degrees was preferred, the addition power curve B shown in Figure 12 should be designed (i.e., the addition power curve should be corrected so that the progressive corridor length is longer). From the above, it was confirmed that it is possible to design an addition power curve according to the subject's preferred angle of eye rotation. [Explanation of symbols]

[0092] 1: Lens frame 10: Frame body 20: Lens holding member 30: Temple material 32: Front temple 34: Rear temple 36: Angle adjustable connection 40: Nose rest frame 200: Bridge member 202: First bending member 202A: Vertical section 202B: Lateral part 204: Second cross member 210: Width adjustment mechanism 212: Lens spacing adjustment mechanism (dial member) 214: Warp angle adjustment mechanism (dial member) 220: Lens frame 222: Lens frame body 224: Column part 230: Connection part 320: First front temple material 322: Second front temple material 324: Length adjustment mechanism 340: First rear temple piece 342: Second rear temple piece 342A: Curved section 344: Length adjustment mechanism 400: First frame material 402: Second bending frame member 404: Third horizontal frame 410: Length adjustment mechanism 420: Width adjustment mechanism 430: Nose rest support 432: Nose rest 500: Progressive power lens 510 :Distance part 520: Near vision area 530: Middle section S100: Measurement process for visual acuity values ​​in downward gaze S101: Aspheric correction inspection S102: Near lateral power correction test S103: Prism Thinning Correction Test S104: Addition curve correction test S110: Design process

Claims

1. A step of setting a plurality of states in which a subject wearing an optometric lens frame looks downward, having the subject compare how the visual target appears, and obtaining a subjective response from the subject; designing spectacle lenses suitable for the subject based on the subjective responses; and In the step of obtaining the subjective response, the plurality of states are set, each having a different angle of eye rotation; A method for designing a spectacle lens, wherein an addition curve is corrected in the step of designing the spectacle lens.

2. A process of setting a plurality of conditions in which a subject wearing an eye examination lens frame looks downward, having the subject compare how the visual target appears, and obtaining a subjective response from the subject; designing spectacle lenses suitable for the subject based on the subjective responses; and In the step of obtaining the subjective response, an ophthalmic lens frame is used, which is configured so that the line of sight of the subject when the subject looks downward coincides with the optical axis of the ophthalmic lens, A method for designing eyeglass lenses, wherein the optometric lens frame is configured so that the distance from a reference point on the back surface of the optometric lens to the corneal vertex of the subject remains constant when the angle of eyeball rotation is changed.

3. 3. The method for designing eyeglass lenses according to claim 2, wherein in the step of obtaining the subjective response, the plurality of conditions are set using a plurality of trial lenses selected so as to simulate an aspherical design.

4. In the step of obtaining the subjective response, the plurality of states are set using a plurality of trial lenses having different spherical powers with respect to a known addition power; 3. The method for designing a spectacle lens according to claim 2, wherein the step of designing the spectacle lens includes correcting a power of a near side portion.

5. 3. The method for designing eyeglass lenses according to claim 2, wherein in the step of obtaining the subjective response, the plurality of states are set using a plurality of trial lenses with different prism amounts.

6. In the step of obtaining the subjective response, the plurality of states are set, each having a different angle of eye rotation; 3. The method for designing a spectacle lens according to claim 2, wherein an addition curve is corrected in the step of designing the spectacle lens.

7. 2. The method for designing eyeglass lenses according to claim 1, wherein the step of obtaining the subjective response uses an optometric lens frame configured so that the line of sight of the subject when the subject looks downward coincides with the optical axis of the optometric lens.

8. 8. The method for designing eyeglass lenses according to claim 7, wherein the trial lens frame is configured so that the distance from a reference point on the back surface of the trial lens to the corneal vertex of the subject is constant when the angle of rotation of the eyeball is changed.

9. A step of having a subject wearing an optometric lens frame look downward in a plurality of states and comparing how the subject sees the visual target, and obtaining a subjective response from the subject; designing spectacle lenses suitable for the subject based on the subjective responses; and In the step of obtaining the subjective response, the plurality of states are set, each having a different angle of eye rotation; A method for manufacturing a spectacle lens, wherein an addition curve is corrected in the step of designing the spectacle lens.

10. A process of having a subject wearing an eye examination lens frame look downward in a plurality of states, comparing how the subject sees an optotype, and obtaining a subjective response from the subject; designing spectacle lenses suitable for the subject based on the subjective responses; and In the step of obtaining the subjective response, an ophthalmic lens frame is used, which is configured so that the line of sight of the subject when the subject looks downward coincides with the optical axis of the ophthalmic lens, A method for manufacturing eyeglass lenses, wherein the ophthalmic lens frame is configured so that the distance from a reference point on the back surface of the ophthalmic lens to the corneal vertex of the subject remains constant when the angle of eyeball rotation is changed.

11. a step of having a test subject wearing a lens frame for eye examination look downward in a plurality of states, and having the test subject compare how the visual target appears in the plurality of states, and obtaining a subjective response from the test subject; In the step of obtaining the subjective response, an ophthalmic lens frame is used, which is configured so that the line of sight of the subject when the subject looks downward coincides with the optical axis of the ophthalmic lens, A method for measuring visual acuity values, wherein the optometric lens frame is configured so that the distance from a reference point on the back surface of the optometric lens to the corneal vertex of the subject remains constant when the angle of eye rotation is changed.

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