JP7186082B2 - Spectacle lens design and manufacturing method - Google Patents

Description

The present invention relates to a method of designing and manufacturing a spectacle lens.

In [0037]-[0043] of Patent Document 1, on the premise of the astigmatic axis direction determined by the Donders-Listing law, the shape of the astigmatic surface, the power of the refractive error of the eye and the astigmatic component are corrected at all eye positions. Techniques designed to do so are described.

JP-A-11-72754

In the following description, the X direction is the optical axis direction from the cornea to the retina, the Y direction is the top and bottom direction, and the Z direction is the direction perpendicular to them, from the ear to the nose in the right eye. direction.

FIG. 1 is a plan view showing the state of eyeball rotation during eye convergence of a spectacle lens wearer.

According to the Donders-Listing law used in Patent Document 1, the posture of the eyeball when facing in an arbitrary direction is a predetermined rotation from the first eye position (the direction when looking straight ahead and far) toward an arbitrary direction. Obtained by rotating along an axis. The rotation axis of the eyeball exists on the YZ plane (Listing's plane in FIG. 1).

The Donders-Listing law used in Patent Document 1 is based on the premise of viewing with only one eye (hereinafter referred to as monocular vision). On the other hand, when we look at things, we have binocular vision, and at that time we see things with both eyes converged. In binocular vision, the posture of the eyeballs when looking in an arbitrary direction is that the eyeballs rotate from the first eye position (the direction when looking straight ahead into the distance) toward an arbitrary direction along a predetermined rotation axis. can get. However, unlike the Donders-Listing law used in Patent Document 1, the rotation axis of the eyeball of each eye during binocular vision is, as shown in FIG. of the velocity plane).

Hereinafter, the conventional Donders-Listing law used in Patent Document 1 is also referred to as the "monocular Listing law", and the Donders-Listing law in the case of binocular vision is also referred to as the "binocular Listing law". called.

When spectacles are actually used, they are usually binocular. According to the technique described in Patent Document 1, the situation at the time of convergence that assumes monocular vision is applied to binocular vision.

An object of one embodiment of the present invention is to provide spectacle lenses that reflect the convergence situation when spectacles are actually used.

A first aspect of the present invention is
Torsion between the eyeball axis after eyeball rotation based on the monocular vision Listing law and the eyeball axis after eyeball rotation based on the binocular vision Listing law at the time of eye convergence of the wearer of the spectacle lens that is a progressive power lens This is a spectacle lens designing method for designing a spectacle lens using a difference angle δ.

A second aspect of the present invention is the aspect according to the first aspect,
In a spectacle lens that is a progressive power lens for one eye that is a progressive power lens, the value obtained by subtracting the torsion difference angle _δ1 of one eye from the value of the astigmatism axis _Ax1 that is one of the prescription values is In the spectacle lens that is used as the new astigmatic axis Ax _1′ and is a progressive power lens for the other one eye, the value of the astigmatic axis Ax ₂ , which is one of the prescription values, is is used as a new astigmatism axis _{Ax2 '} to design a pair of spectacle lenses.

但し、Ｘ方向を光軸方向であって角膜から網膜に向かう方向とし、Ｙ方向を天地の天の方向とし、Ｚ方向をそれらに垂直な方向であって右眼において耳から鼻に向かう方向としたとき、
ｌ、ｍ、ｎ ： 眼球の向く方向の単位ベクトル
ａ^＊＝ｌ×ｉ^＊＋ｍ×ｊ^＊＋ｎ×ｋ^＊ ・・・（式２）
における各係数であり、ｉ^＊はＸ方向でのベクトル、
ｊ^＊はＹ方向でのベクトル、ｋ^＊はＺ方向でのベクトルであり、
ｔ ： 右眼の場合はｔａｎφ、左眼の場合は－ｔａｎφ
φ ： α／５～α／３の範囲の一つの値
α ： 輻輳角
である。 A third aspect of the present invention is the aspect according to the second aspect,
a torsion difference angle acquisition step of obtaining a torsion difference angle δ using the following (Equation 1);
design process;
have

However, the X direction is the direction of the optical axis and is the direction from the cornea to the retina, the Y direction is the top and bottom direction, and the Z direction is the direction perpendicular to them and is the direction from the ear to the nose in the right eye. when
l, m, n : unit vector in the eyeball direction
a ^* =l×i ^* +m×j ^* +n×k ^* (Formula 2)
, i ^* is the vector in the X direction,
j ^* is the vector in the Y direction, k ^* is the vector in the Z direction,
t: tanφ for right eye, -tanφ for left eye
φ: One value in the range from α/5 to α/3 α: Convergence angle.

A fourth aspect of the present invention is the aspect according to any one of the first to third aspects,
The eyeball axis is an axis perpendicular to the eye axis that passes through the corneal vertex and the fovea centralis and is a vertical axis in the vertical direction for the eyeball, or an axis perpendicular to the eye axis and the vertical axis for the eyeball It is the left-right axis in the left-right direction.

A fifth aspect of the present invention is
Torsion between the eyeball axis after eyeball rotation based on the monocular vision Listing law and the eyeball axis after eyeball rotation based on the binocular vision Listing law at the time of eye convergence of the wearer of the spectacle lens that is a progressive power lens A spectacle lens manufacturing method for designing a spectacle lens using a differential angle δ and processing the spectacle lens based on the design.

According to an embodiment of the present invention, it is possible to provide spectacle lenses that reflect the convergence situation when spectacles are actually used.

FIG. 1 is a plan view showing the state of eyeball rotation during eye convergence of a spectacle lens wearer. FIG. 2 is an explanatory diagram when a ^* and x ^* are projected onto a plane normal to the unit vector b ^* of the rotation axis B. FIG. FIG. 3 is an example of a general formula, and is an explanatory diagram showing how r' ^* is obtained after r ^* is rotated by θ around n ^* .

In the present specification, "~" refers to a predetermined value or more and a predetermined value or less.
In addition, in this specification, ^* is attached to vectors, or symbols corresponding to vectors are expressed in bold letters in formulas.

One aspect of the present invention will be described below. The following description is exemplary, and the present invention is not limited to the illustrated embodiments.

[Method for designing spectacle lens according to one aspect of the present invention]
A method for evaluating the spectacle lens according to one aspect of the present invention is as follows.
"At the time of convergence of the eye of the wearer of the spectacle lens, which is a progressive power lens, between the eyeball axis after eyeball rotation based on the monocular Listing law and the eyeball axis after eyeball rotation based on the binocular Listing law A spectacle lens designing method for designing a spectacle lens using a torsion difference angle δ.

The ocular axis is an axis other than the so-called ocular axis (that is, the X axis) that passes through the corneal vertex and the fovea, and is an axis that can represent the torsion difference angle δ. Since the torsion difference angle δ is an angle around the eye axis, it is possible to express the torsion difference angle δ using an axis other than the eye axis.

Specifically, the eyeball axis is an axis perpendicular to the eye axis that passes through the corneal vertex and the fovea and is a vertical axis (ocular Y axis) in the vertical direction of the eyeball, or an axis along the eyeball and the vertical axis. The left-right axis (eyeball Z-axis) is an axis perpendicular to the eyeball and in the left-right direction for the eyeball.
The vertical axis is the axis in the direction from the bottom of the eyeball to the zenith when the eyeball is looking at an infinitely distant object.
The left-right axis is the axis in the horizontal direction from the part closest to the ear to the part closest to the nose when the eyeball is looking at an object at infinity.

Incidentally, any direction other than the vertical axis and the horizontal axis may be defined as an axis. However, in that case, it is necessary to newly derive a formula corresponding to (Formula 1). Therefore, it is preferable to use the vertical axis and the horizontal axis determined from the eye axis as in one aspect of the present invention.
For convenience of explanation, the vertical axis will be exemplified below, but the torsion difference angle .delta.

The vertical axis after eyeball rotation based on the monocular listing rule is the Y axis itself, as shown in FIG. On the other hand, when based on the binocular Listing rule, the vertical axis after eyeball rotation deviates from the Y axis itself. In other words, the torsion difference angle δ in this specification refers to the vertical axis (or horizontal axis) of the eyeball after the eyeball rotates based on the monocular Listing law, and the eyeball after the eyeball rotates based on the binocular Listing law It is the angle between the vertical axis (or horizontal axis) of the eyeball.

According to the technique described in Patent Document 1, the situation at the time of convergence that assumes monocular vision is applied to binocular vision. On the other hand, according to one aspect of the present invention, spectacle lenses are designed using the torsion difference angle δ from the eyeball axis after eyeball rotation based on monocular Listing's law. That is, between the eyeball axis after eyeball rotation based on the "monocular Listing rule" and the eyeball axis after eyeball rotation based on the "binocular Listing rule" that corresponds the monocular Listing rule to the case of binocular vision A spectacle lens is designed using the torsion difference angle δ.

As a result, it is possible to provide spectacle lenses that reflect the convergence situation when spectacles are actually used. This means that the wearing dioptric power (so-called check dioptric power) used when checking the dioptric power of spectacle lenses at an eyeglass shop can be made more accurate. Further, according to one aspect of the present invention, there is also an advantage that an accurate wearing power can be obtained without requiring a special device.

[Details of Method for Evaluating Spectacle Lenses According to One Embodiment of the Present Invention]
Further specific examples, preferred examples, and modified examples of one aspect of the present invention are described below.

A spectacle lens according to one aspect of the present invention is a progressive power lens. Hereinafter, spectacle lenses refer to progressive power lenses unless otherwise specified. Specifically, it is a pair of progressive-power lenses for left and right eyes, namely, a right-eye progressive-power lens and a left-eye progressive-power lens.

The progressive power lens in this specification includes a first refractive part having a first refractive power, a second refractive part having a second refractive power higher than the first refractive power, and the first refractive power It has a progressive refracting section in which the refractive power changes progressively from the first refracting section to the second refracting section. The second refractive section is positioned below the center of the lens and the first refractive section is positioned above the second refractive section.

When the progressive power lens is a bifocal lens, the first refracting part is a distance part having a power corresponding to a far distance (e.g., infinity), and the second refracting part is a near distance relative to the far distance. It means the near part with the power corresponding to the distance.
When the progressive power lens is a near-to-middle lens, the first refractive part is an intermediate part having a power corresponding to the intermediate distance (eg, about 1 m), and the second refractive part is a near distance compared to the intermediate distance. (eg reading distance 40 cm).

Further, in the progressive-power lens in this specification, at least one of the object-side surface and the eyeball-side surface may be a progressive surface. In one aspect of the present invention, an inner surface progressive lens in which the eyeball side surface is a progressive surface and the object side surface is a spherical surface is exemplified.

(torsion difference angle acquisition process)
In this step, the torsion difference angle δ is obtained using the above (Equation 1). Derivation of (Formula 1) will be described below with reference to FIG. In the following example, the case of obtaining the torsion difference angle _δ1 for the right eye will be described.
Incidentally, when viewing an object on the median plane, the directions of the left and right eyes are symmetrical. In that case, the torsion difference angle _δ2 of the left eye has the same absolute value as _δ1 , while the direction of rotation of the right and left eyes from the first eye position in an arbitrary direction is Z Since they are opposite in direction, they are labeled with the opposite sign of _.delta.1 .
On the other hand, when viewing an object at a position other than the median plane, that is, at an oblique position, the directions of the left and right eyes become asymmetrical. In that case, the torsion difference angle _δ1 for the right eye and the torsion difference angle _δ2 for the left eye do not have the same absolute value. In this case, the torsion difference angle δ (ie, δ ₁ or δ ₂ ) for each eye would be obtained using (Equation 1) above. At that time, the value of t (and thus the value of φ) in (Formula 5) described later is set correctly for each eye.
In one aspect of the present invention, for simplicity of explanation, it is assumed that an object on the median plane is viewed.

φ in FIG. 1 may be one value in the range of α/5 to α/3, but α/4 is exemplified in one aspect of the present invention. That is, in the following examples, the case where the velocity plane, which is the plane having the rotation axis of each eyeball when both eyes are simultaneously rotated in an arbitrary direction from the first eye position, is tilted from the YZ plane by α/4 state.

When the velocity plane is tilted from the YZ plane by α/4 in binocular vision, the first eye position unit vector x ^* is as follows.

ｌ、ｍ、ｎ ： まっすぐ前方遠くを見るときの眼位を第１眼位としたときの
第１眼位単位ベクトルをｉ^＊としたときの、輻輳時の眼位単位ベクトル
ａ^＊＝ｌ×ｉ^＊＋ｍ×ｊ^＊＋ｎ×ｋ^＊ ・・・（式２）
における各係数であり、ｉ^＊はＸ方向でのベクトル、
ｊ^＊はＹ方向でのベクトル、ｋ^＊はＺ方向でのベクトルである。
なお、まっすぐ前方遠くを見るときの第一眼位の場合、ｌ＝１，ｍ＝０，ｎ＝０、つまり、ａ^＊＝ｉ^＊である。 The target eye position unit vector a ^* in binocular vision is as follows. Note that the reaching eye position refers to the eye position in which both eyes are converged (the eye position at the time of convergence), and is not limited to near vision.

l, m, n: When the eye position when looking straight ahead is the first eye position
Eye position unit vector at the time of convergence when the first eye position unit vector is i ^*
a ^* =l×i ^* +m×j ^* +n×k ^* (Formula 2)
, i ^* is the vector in the X direction,
j ^* is the vector in the Y direction and k ^* is the vector in the Z direction.
In the case of the first eye position when looking straight ahead into the distance, l=1, m=0, n=0, that is, a ^* =i ^* .

In order to obtain the torsion difference angle δ, the vertical axis of the eyeball rotated at the rotation angle θ from the first eye position unit vector x ^* in binocular vision to the reached eye position unit vector a ^* , and the vertical axis in monocular vision It is necessary to obtain the vertical axis of the eyeball rotated at the rotation angle θ ₀ from the single eye position unit vector to the reached eye position unit vector. The rotation angle θ ₀ in monocular vision and its rotation axis can be obtained by a conventional method. Therefore, in one aspect of the present invention, it is necessary to newly obtain the rotation angle θ and its rotation axis B in binocular vision.

The axis rotating from the first eye position to the reached eye position is equiangular with the first eye position unit vector x ^* and the reached eye position unit vector a ^* . That is, the rotation axis B exists in the plane formed by x ^* +a ^* and x ^* xa ^* . A vector B ^* of this rotation axis B is shown as follows.

ｔ ： 右眼の場合はｔａｎφ、左眼の場合は－ｔａｎφ
φ ： 図１のＸ－Ｚ平面における、Ｌｉｓｔｉｎｇ‘ｓ ｐｌａｎｅをＹ軸周りに回転させてＶｅｌｏｃｉｔｙ ｐｌａｎｅになる際の回転角。α／５～α／３の範囲の一つの値（本発明の一態様だとα／４）
α ： 輻輳角
（式５）を変形させると以下の式となる。

The vector B ^* of the rotation axis B is on the velocity plane inclined by α/4 from the YZ plane. Therefore, the following formula holds.

t: tanφ for right eye, -tanφ for left eye
φ: Rotation angle in the XZ plane of FIG. 1 when the Listing's plane is rotated around the Y-axis to become the velocity plane. One value in the range of α/5 to α/3 (α/4 in one aspect of the present invention)
α: Angle of convergence The following formula is obtained by transforming (Formula 5).

The following formula is established from (Formula 4) and (Formula 6).

As a result, the unit vector b ^* of the rotation axis B is represented by the following equation.

Next, the rotation angle θ in binocular vision is obtained.
FIG. 2 is an explanatory diagram when a ^* and x ^* are projected onto a plane normal to the unit vector b ^* of the rotation axis B. FIG.
When a ^* and x ^* are projected onto a plane normal to b ^* as shown in FIG. 2 in order to obtain the rotation angle θ, the following equation holds.

但し、Ｍは以下の式で表される。

The lengths (absolute values, scalar) of a ^* and x ^* are obtained by the following equations.

However, M is represented by the following formula.

（式１４）により、両眼視における回転軸Ｂの回転角θが得られる。 The following formula is derived from (Formula 9) to (Formula 13).

The rotation angle θ of the rotation axis B in binocular vision is obtained from (Equation 14).

Next, the eyeball coordinate axes for the rotation angle θ in binocular vision are obtained.
FIG. 3 is an example of a general formula, and is an explanatory diagram showing how r' ^* is obtained after r ^* is rotated by θ around n ^* .
A general formula for obtaining r' ^* shown in FIG.

When (Equation 15) is used, the x-axis changes to x ₁ ^* by rotating the rotation axis B by θ. The formula is the following formula.

When (Equation 15) is used, the y-axis changes to y ₁ ^* by rotating the rotation axis B by θ. The formula is the following formula.

When (Equation 15) is used, the z-axis changes to z ₁ ^* by rotating the rotation axis B by θ. The formula is the following formula.

The following formula summarizes the above [Formula 16] to [Formula 18]. The following equations represent the eyeball coordinate axes after being rotated by the rotation angle θ based on the binocular listing rule. Of these eyeball coordinate axes, y ₁ ^* represents the vertical axis (direction from bottom to top) for the eyeball after eyeball rotation based on the binocular Listing's law. Note that z ₁ ^* represents the left-right axis (the direction from the ear to the nose) for the eyeball after eyeball rotation based on the binocular Listing's law.

Note that the eyeball coordinate axis based on the monocular Listing's law is the case where φ in FIG. 1 is zero, that is, α is zero. That is, t=0 in (Equation 5). As a result, the eyeball coordinate axes based on the monocular listing rule are represented by the following equations. Of these eyeball coordinate axes, y ₁₀ ^* represents the vertical axis (direction from bottom to top) for the eyeball after eyeball rotation based on the monocular Listing's law. Note that z ₁₀ ^* represents the left-right axis (the direction from the ear to the nose) for the eyeball after eyeball rotation based on the binocular Listing's law.

As a result of the above, (Formula 1) is obtained by the following derivation process. As a result, the torsion difference angle δ can be calculated. The same equation (1) can be obtained even when the horizontal axis is used instead of the vertical axis.

(Design process)
In this step, a spectacle lens is designed based on the torsion difference angle δ obtained in the torsion difference angle obtaining step.

According to the conventional method, the residual astigmatism of the spectacle lens is evaluated in the coordinate system of the target eye position determined by the monocular Listing rule. Even if residual astigmatism appears to be completely corrected, residual astigmatism due to the torsion difference angle δ exists when evaluated in the coordinate system of the target eye position determined by the binocular Listing's rule.

The definition of residual astigmatism is as follows.
Originally, in the vicinity of the intersection of the principal ray, which is the optical axis, and the spectacle lens, where the spectacle lens wearer rotates the eye to an arbitrary third eye position (posterior convergence position), the degree of refractive error and astigmatism of the eye Ideally, it should be designed to correct the component perfectly. However, in practice, the refractive error power and astigmatic component of the eye may only be partially corrected. The refractive error component that cannot be completely corrected is called residual aberration. This residual aberration is represented by two amounts of aberration, residual astigmatism and average power error. In one aspect of the present invention, residual astigmatism is addressed.

In one aspect of the invention, the binocular Listing rule is used instead of the monocular Listing rule in the process of calculating the residual astigmatism of each point on the spectacle lens. Then, the torsion difference angle between the eyeball axes (vertical axis, lateral axis) after eyeball rotation based on monocular Listing's law and the eyeball axis (vertical axis, lateral axis) after eyeball rotation based on binocular Listing's law The design process is performed using δ.

In one aspect of the present invention, it is preferable to design the spectacle lens by reflecting the torsion difference angle δ on the astigmatic axis Ax, which is one of the prescription values. Similar to the torsion difference angle δ, the astigmatism axis Ax is also an angle around the eye axis (X-axis). Therefore, the astigmatism axis Ax is susceptible to the torsion difference angle δ. As a result, when the torsion difference angle δ is reflected, the effect of improving residual astigmatism is large.

To give an example of the reflection method, in a spectacle lens that is a progressive power lens for one eye, the torsion difference angle δ ₁ for one eye is subtracted from the value of the astigmatic axis Ax ₁ , which is one of the prescription values. is used as a new astigmatic axis Ax _{1 '} , and in the spectacle lens that is the progressive power lens for the other one eye, the other value of the astigmatic axis Ax ₂ , which is one of the prescription values, is A value obtained by subtracting the torsion difference angle δ ₂ of one eye is preferably used as the new astigmatism axis Ax _2′ .

As a specific work content, it is assumed that the value of the astigmatism axis _Ax1 and the value of the astigmatism axis _Ax2 are equal.

For example, both the left and right eyeglass lenses have astigmatic axes Ax of 90°, 30° downward, on the median plane (a plane perpendicular to a straight line passing through the center of left and right eye rotation and passing through the center of left and right eye rotation) Let us calculate the case of looking at a point 30 cm (300 mm) near.
PD is 32 mm for both left and right eyes.
In this case, each parameter is as follows.
Convergence angle α = 2 × arcsin(32/300) = 12.25 degrees φ = α/4 = 3.06 degrees Right eye: t = tan φ = 0.053486, direction cosine l = 0.861085, m = 0 .497147, n=0.106667.
Left eye: t=−tanφ=−0.053486, direction cosines l=0.861085, m=0.497147, n=−0.106667.
By substituting these parameters into (Equation 1) and calculating,
Right eye torsion difference angle δ ₁ = -1.632°
Left eye torsion difference angle δ ₂ = +1.632°
is obtained.
in this case,
The astigmatic axis Ax ₁ of the spectacle lens for the right eye is 90−δ ₁ =91.632°
year,
The astigmatic axis Ax ₂ of the spectacle lens for the left eye is 90−δ ₂ =88.368°
Remaining astigmatism can be eliminated by designing the spectacle lens as

As described in paragraph 0032, the above example assumes that the object is the median plane. In the case of objects, _δ1 and _δ2 do not necessarily have that relationship.

As a result, it is possible to reduce (preferably eliminate (cancel)) residual astigmatism due to the torsion difference angle δ.

In addition, if the absolute value of the astigmatism power C, which is one of the prescription values, exceeds zero and is 1.0 D or more (preferably 2.0 D or more, more preferably 3.0 D or more), residual astigmatism Great improvement.
In addition, although it has been described that the eye position to be reached is not limited to near vision, the improvement effect is large when the convergence angle of the eye is large and convergence in near vision.

(A series of operations including confirmation of residual astigmatism)
A series of work examples in the torsion difference angle acquisition process and the design process after applying the mathematical method for obtaining the torsion difference angle δ will be described below. The working example of one aspect of the invention uses ray tracing.

First, a virtual optical model of the spectacle lens before application of the torsion difference angle δ is constructed. Prescription values of spectacle lenses (spherical power S, cylinder power C, cylinder axis Ax, addition power ADD, prism value Δ, etc.) are used in constructing a reference lens model in a virtual optical model including eyeglass lens arrangement and eyeball arrangement. do. Since the construction of the virtual optical model may adopt the method described in Japanese Patent No. 5969631, the details are omitted here.

Next, as described in Japanese Patent No. 5969631, a spectacle lens design computer (not shown) determines a reference object plane including a plurality of object planes arranged at different object distances based on the reference lens model. , are defined to be common to the left and right eyes corresponding to physiologically equal accommodative powers of the left and right eyes. The object plane used in the design of spectacle lenses has an object distance corresponding to the near power at the near power measurement reference point and an object distance (5000 mm) corresponding to the distance power (reference power) at the distance power measurement reference point. (such as a distance that can be regarded as infinite).

Next, as described in Japanese Patent No. 5969631, the spectacle lens design computer performs optical calculation processing using ray tracing or the like, so that the chief ray from an arbitrary point on the object plane passes through. , positions (reference-side chief ray passage positions) on the left and right reference lens models (here, on the outer surface of the lens) are calculated. Here, a chief ray is defined as a ray directed from an arbitrary point on the reference object plane toward the center of rotation of the eyeball. Then, the spectacle lens design computer calculates reference-side principal ray passing positions corresponding to arbitrary points on each object surface so that the reference-side principal ray passing positions are arranged on the entire outer surface of the reference lens model.

This operation determines the passing point of light rays on the spectacle lens when the wearer looks at a point on the object plane through the spectacle lens. At the same time, the angle of convergence is also obtained by ray tracing measurements. And by ray tracing measurements and mathematical methods, the torsion difference angle δ is also obtained.

For example, assuming that the interpupillary distance (PD) is 64 mm, the visual distance is 40 cm, the eyeball downward rotation angle is 30°, and an object on the median plane is viewed, sin δ ₁ of the right eye is −0.0217. , that is, δ ₁ =−1.243° for the right eye. For the left eye, δ ₂ =1.243°.

Based on the above information, residual astigmatism at each point on the spectacle lens is calculated. As a result, if it is one aspect of the present invention, as a result of reflecting the situation at the time of convergence when actually using spectacles on each spectacle lens for left and right eyes, which is a progressive power lens, residual astigmatism can be eliminated. .

The technical idea of the present invention is also reflected in the method of manufacturing a spectacle lens using the method of designing a spectacle lens, which is one aspect of the present invention. The mode is as follows.
"At the time of convergence of the eye of the wearer of the spectacle lens, which is a progressive power lens, between the eyeball axis after eyeball rotation based on the monocular Listing law and the eyeball axis after eyeball rotation based on the binocular Listing law A method for manufacturing a spectacle lens, which comprises designing a spectacle lens using a torsion difference angle δ and processing the spectacle lens based on the design.

While one aspect of the present invention has been described above, the foregoing disclosure presents one exemplary aspect of the present invention. That is, the technical scope of the present invention is not limited to the exemplary embodiment described above, and can be modified in various ways without departing from the gist of the invention.

An embodiment of the present invention will be described below. The invention is not limited to the following examples.

The interpupillary distance (PD) is set to 70 mm, the visual distance to the target is 33 cm, and the downward eye rotation angle is set to 20°. And it was assumed that the torsion difference angle δ=2°. In this state, astigmatism powers C of 1.00D, 2.00D, and 3.00D were assumed.

The residual astigmatism calculated by the monocular Listing rule is 0.035D for C=1.00D, 0.07D for C=2.00D, and 0.07D for C=3.00D. 105D. Note that the method described in one aspect of the present invention was used as the method for calculating the residual astigmatism. At that time, the PD, the visual distance, the eyeball downward rotation angle, and C were used for calculation instead of using a lens model of a progressive power lens of a specific design.

Then, when the value of the astigmatism axis Ax of the progressive power lens for each eye is set to a new value by the method described in one aspect of the present invention, even when C=1.00D, C=2.00D. , and C=3.00D, the residual astigmatism was zero (0.000D). In other words, according to one embodiment of the present invention, as a result of reflecting the situation at the time of convergence when actually using spectacles on the respective spectacle lenses for the left and right eyes, which are progressive power lenses, residual astigmatism becomes zero. I found out.

<Summary>
Hereinafter, the "spectacle lens design method and manufacturing method" of the present disclosure will be summarized.
One embodiment of the disclosure is as follows.
Torsion between the eyeball axis after eyeball rotation based on the monocular vision Listing law and the eyeball axis after eyeball rotation based on the binocular vision Listing law at the time of eye convergence of the wearer of the spectacle lens that is a progressive power lens A spectacle lens designing method for designing a spectacle lens using a differential angle δ.

Claims (5)

Torsion between the eyeball axis after eyeball rotation based on the monocular vision Listing law and the eyeball axis after eyeball rotation based on the binocular vision Listing law at the time of eye convergence of the wearer of the spectacle lens that is a progressive power lens A spectacle lens designing method for designing a spectacle lens using a differential angle δ. In a spectacle lens that is a progressive power lens for one eye that is a progressive power lens, the value obtained by subtracting the torsion difference angle _δ1 of the one eye from the value of the astigmatism axis _Ax1 that is one of the prescription values is used as a new astigmatic axis Ax _{1 '} , and in the spectacle lens which is a progressive power lens for the other one eye, the value of the astigmatic axis Ax ₂ , which is one of the prescription values, is 2. The spectacle lens designing method according to claim 1 , comprising a designing step of designing a pair of spectacle lenses using a value obtained by subtracting the torsion difference angle _δ2 of one eye as a new astigmatism axis Ax2 _' . a torsion difference angle acquiring step of obtaining the torsion difference angle δ using the following (Equation 1);
the design process;
The spectacle lens designing method according to claim 2, comprising:

However, the X direction is the direction of the optical axis and is the direction from the cornea to the retina, the Y direction is the top and bottom direction, and the Z direction is the direction perpendicular to them and is the direction from the ear to the nose in the right eye. when
l, m, n : unit vector in the eyeball direction
a ^* =l×i ^* +m×j ^* +n×k ^* (Formula 2)
, i ^* is the vector in the X direction,
j ^* is the vector in the Y direction, k ^* is the vector in the Z direction,
t: tanφ for right eye, -tanφ for left eye
φ: One value in the range from α/5 to α/3 α: Convergence angle. The eyeball axis is an axis perpendicular to the eye axis that passes through the corneal vertex and the fovea centralis and is a vertical axis in the vertical direction of the eyeball, or an axis perpendicular to the eye axis and the vertical axis. 4. The spectacle lens designing method according to any one of claims 1 to 3, wherein the left-right axis is the right-left axis for the eyeball. Torsion between the eyeball axis after eyeball rotation based on the monocular vision Listing law and the eyeball axis after eyeball rotation based on the binocular vision Listing law at the time of eye convergence of the wearer of the spectacle lens that is a progressive power lens A spectacle lens manufacturing method comprising designing a spectacle lens using a differential angle δ and processing the spectacle lens based on the design.

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