JP2012185426A - Method for selecting spectacle frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for selecting a spectacle frame to which progressive power lenses having a sufficient additional power can be attached.SOLUTION: When a spectacle frame to which a progressive power lens 1 having an inner surface IS having a progressive zone formed therein and a spherical outer surface OS is to be attached is selected from a plurality of spectacle frames different in top-to-bottom depth, a progressive zone length set on the basis of prescription for a wearer is supposed, and a measurement point for near vision is set in relation with an end point of the progressive zone length, and this measurement point for near vision is supposed to select a spectacle frame having a proper frame height.

Description

  The present invention relates to a method for selecting a spectacle frame to which a progressive addition lens having a progressive area formed on the inner surface on the eyeball side is attached.

  In addition to single-focus spectacle lenses, there are progressive-power spectacle lenses. As this progressive-power eyeglass lens, a distance area having a refractive power (frequency) corresponding to far vision, a near area having refractive power corresponding to near vision, and these distance area and near area There is an aspherical lens having a progressive area provided between the intermediate areas and intermediate lateral areas provided on both sides of the progressive area. And the main gaze line (main meridian) is formed in the approximate center of the distance area, the progressive area, and the near area.

This main line of sight is a virtual line on the lens through which the line of sight passes when an eyeglass wearer sees an object from the upper front to the lower front, and is normally along the vertical in the distance area and the near area. Then, it is inset on the nose side due to the convergence during near vision. Furthermore, the length along the main gazing line (up and down) between the progressive start point and the progressive end point in the progressive region is the progressive zone length.
Conventionally, in designing a progressive-power lens, an equivalent spherical power at a near measurement point (center of the near measurement area) located on the main gaze line in the near area is set.
Furthermore, the progressive zone length is set according to the prescription of the wearer, and is selected from among a number of spectacle frames having a number of spectacle frames having a sufficient length.

Conventionally, there is a lens design method in which individual data of a wearer is acquired and the position of a reference point of a near portion is determined (Patent Document 1). In the conventional example of Patent Document 1, the reference point of the near portion is preferably 2 mm above the end portion of the lower frame.
Further, there is a conventional example of a spectacle lens selection method in which a distance eye point and a near eye point of a wearer are measured and an optimum progressive band length is set based on these measurements (Patent Document 2).
Furthermore, there is a conventional example of a method for designing a progressive power lens having progressive characteristics suitable for an arbitrary frame shape (Patent Document 3). In the conventional example of Patent Document 3, for example, in the case of a frame having a small top and bottom width, a lens having a short progressive zone length that can accommodate a near-use area is selected.

Special table 2010-517088 JP-A-6-63015 Special table 2010-66421

In the progressive-power lens, even if the light passes through the lens and enters the eyeball, the light in the region that does not pass through the lens outer surface cannot be optically used.
In the conventional example shown in Patent Document 1, since the reference point of the near portion is 2 cm above the end of the lower frame, there is a possibility that the near measurement point may enter the above optically unusable region. If the near measurement point enters an area where it cannot be used optically, a sufficient addition cannot be obtained with the progressive-power lens.

In the conventional example shown in Patent Document 2, an optimum progressive zone length is set from the measured distance eye point and near eye point. In setting this progressive zone length, the above-mentioned optical zone length is set. Even areas that cannot be used are not considered. For example, if the vertical width of the frame is small, a near-field measurement point may enter an area that cannot be used optically. In this case, sufficient addition with the progressive-power lens cannot be obtained.
In the conventional example shown in Patent Document 3, a method for obtaining a clear progressive zone length is not disclosed, and a sufficient addition degree is not always obtained.
The above conventional example is a progressive power lens that may cause a near measurement point to enter an optically unusable region, and in the spectacles in which this progressive power lens is attached to a spectacle frame in the same manner as in the past, A sufficient addition cannot be obtained.

  An object of the present invention is to provide a method for selecting a spectacle frame to which a progressive addition lens having a sufficient addition can be attached.

The present inventors set a point closer to the fitting point than a ray passing through the outermost surface of the progressive addition lens and entering the center of rotation of the eyeball through a point farthest from the fitting point as a near measurement point. By doing so, we decided to achieve the above-mentioned purpose.
The method for selecting a spectacle frame according to the present invention includes a distance region and a near region, an inner surface that is a refractive surface on the eyeball side, and an outer surface that is a refractive surface on the object side, and a progressive region formed on the inner surface. A method of selecting a spectacle frame to which a refracting lens is attached, wherein a progressive zone length, which is a length along a main meridian between a progressive start point and a progressive end point, is determined by a wearer's prescription, A near-measurement point is set at a point on the main meridian that is closer to the outer peripheral edge of the progressive-power lens than the progressive end point, and is emitted from the center of rotation of the eyeball and passes through this near-measurement point A point at which a light ray passes through the outer surface is obtained by a ray tracing method, and a spectacle frame having a frame height at which this point falls within the frame is selected.
In the present invention of this configuration, assuming the progressive zone length set based on the wearer's prescription, the near-measurement point is set in relation to the progressive end point of this progressive zone length, As a premise, a spectacle frame having an appropriate frame height is selected, so that a sufficient addition can be obtained in the inner surface progressive lens. Moreover, even if the optical non-use region changes due to a change in the forward tilt angle of the progressive power lens or the distance between the inner surface of the lens and the corneal apex of the wearer's eyeball (distance between the corneal apexes), Since the optical non-use area is obtained by the ray tracing method, a spectacle frame corresponding to the wearing condition can be selected.

In the present invention, the progressive-power lens has a peripheral part of which is fitted into a concave part on the inner peripheral part of the spectacle frame, passes through the main meridian in the near-use area on the outer surface, and passes through the center of the eyeball. It is preferable that the point that is the most distant from the fitting point in the light ray is a point on the outer peripheral edge at which the outer surface where the spectacle frame of the progressive-power lens is not fitted and the outer surface intersect.
In the present invention having this configuration, a sufficient addition can be obtained in a so-called lens mounted on a so-called nyroll frame in which a part of the lens is covered with a frame.

In the present invention, the progressive-power lens has a peripheral portion of the entire circumference fitted into a concave portion of the inner peripheral portion of the spectacle frame, passes through the main meridian in the near-use region of the outer surface, and passes through the center of the eyeball. It is preferable that the point which is the light ray and is farthest from the fitting point is on a line where the inner peripheral edge of the spectacle frame intersects the outer surface.
In the present invention having this configuration, a sufficient addition can be obtained in a so-called metal frame in which the peripheral portion of the lens is covered with a frame or a lens attached to a cell frame.

In the present invention, a light ray that passes through the principal meridian in the far-field region of the outer surface and passes through the center of the eyeball, the light ray passing through the point farthest from the fitting point is obtained, and the light ray passes through the inner surface. A distance measurement point is set at a point closer to the fitting point than the fitting point, and a point on the main meridian on the inner surface, and is emitted from the center of rotation of the eyeball, and rays passing through the distance measurement point pass through the outer surface. A configuration in which a progressive power lens is provided in which a passing point is obtained by a ray tracing method and the point is within a frame is preferable.
In the present invention of this configuration, the distance measurement point is set based on the progressive zone length set based on the wearer's prescription, and the distance measurement point is set in relation to the progressive end point of the progression band length. As a premise, a spectacle frame having an appropriate frame height is selected, so that a sufficient addition can be obtained in the inner surface progressive lens.

In the present invention, a part of the peripheral portion of the progressive-power lens is fitted into the inner peripheral recess of the spectacle frame, passes through the main meridian in the distance area on the outer surface, and passes through the center of the eyeball. It is preferable that the point that is the most distant from the fitting point is a point on the outer periphery where the edge surface of the progressive-power lens that is not fitted with the eyeglass frame and the outer surface intersect. .
In the present invention having this configuration, a sufficient addition can be obtained in a so-called lens mounted on a so-called nyroll frame in which a part of the lens is covered with a frame.

In the present invention, the progressive-power lens has a peripheral portion of the entire periphery fitted into a concave portion of the inner peripheral portion of the spectacle frame, passes through a main meridian in the distance area on the outer surface, and passes through the center of the eyeball. It is preferable that the point which is the light ray and is farthest from the fitting point is on a line where the inner peripheral edge of the spectacle frame intersects the outer surface.
In the present invention having this configuration, a sufficient addition can be obtained in a so-called metal frame in which the peripheral portion of the lens is covered with a frame or a lens attached to a cell frame.

The perspective view which shows the spectacles concerning 1st Embodiment of this invention. Schematic of the front of the progressive-power lens before processing a target lens. The schematic of the perpendicular direction of the progressive addition lens after processing a target lens shape. The perspective view which shows the spectacles concerning 2nd Embodiment of this invention. The schematic of the perpendicular direction of the progressive addition lens after processing a target lens shape. The schematic diagram of the front of the progressive-power lens before showing target lens shape processing which shows 3rd Embodiment of this invention.

Embodiments of the present invention will be described with reference to the drawings. Here, in each embodiment, the same constituent elements are denoted by the same reference numerals, and description thereof is omitted or simplified.
1 to 3 show a first embodiment of the present invention.
FIG. 1 shows spectacles according to the first embodiment.
In FIG. 1, the first embodiment is an example of spectacles in which a progressive addition lens 1 is attached to a nyroll spectacle frame 2.
The spectacle frame 2 includes a pair of rims 21 each holding the progressive addition lens 1, a bridge 22 connecting the rims 21, a nose pad 23 provided on the nose side of the rim 21, and an ear of the rim 21. And a vine 24 provided on the side.
In the present embodiment, the progressive addition lens 1 has an upper peripheral edge fitted in a recess (not shown) of the rim 21. The center of the lower peripheral edge of the progressive-power lens 1 is locked with a nylon thread (not shown), and the inner and outer corners are exposed.

2 and 3 show a configuration of the progressive-power lens 1 according to the first embodiment. FIG. 2 shows an outline of the front of the progressive-power lens 1 before processing the target lens shape, and FIG. 3 shows an outline of the progressive-power lens 1 after processing the target lens shape in the vertical direction. In FIG. 3, the rim 21 is not shown.
In FIG. 2, the progressive addition lens 1 according to the first embodiment includes a distance region 11 having a refractive power corresponding to far vision, a near region 12 having a refractive power corresponding to near vision, and these far-field regions. A progressive area 13 provided between the area 11 and the near area 12 and intermediate side areas 14 provided on both sides of the progressive area 13 for viewing both far and near It is an aspheric lens. Here, the distance region 11 may be a region having a refractive power for visually recognizing a medium distance or a short distance. The near region 12 may be a region having a refractive power larger than that of the far region, and may be a region having a refractive power for visually recognizing a middle distance or a short distance. These progressive surfaces are provided on the inner surface on the eyeball side, and the outer surface on the object side is a spherical surface.

A main meridian A is formed substantially at the center of the distance region 11, the progressive region 13, and the near region 12. The main meridian A is also referred to as a main gazing line, and is a virtual line on the lens through which the line of sight passes when an eyeglass wearer views an object located from the upper front to the lower front.
The main meridian A is along the vertical in the distance area 11 and in the near area 12 is inset (inset) by a dimension B to the nose due to the convergence during near vision.
On the main meridian A of the distance area 11, a distance measurement point DP that is the center of the distance measurement area is provided, and the equivalent spherical power in the distance area 11 is set.
On the main meridian A of the near vision area 12, a near measurement point NP that is the center of the near vision measurement area is provided, and an equivalent spherical power in the near vision area 12 is set.
A fitting point FP is set on the main meridian A as an origin.
In the progressive region 13, the length along the top and bottom between the progressive start point PS and the progressive end point PE is defined as a progressive zone length P.
The distance from the fitting point FP to the lens upper edge is the frame upper height Oh, and the distance from the fitting point FP to the lens lower edge is the frame lower height Bh.

In FIG. 3, the progressive-power lens 1 has an inner surface IS on the eyeball side and an outer surface OS on the object side, and an edge surface RS which is an outer peripheral edge and connects the inner surface IS and the outer surface OS. The center thickness at is t. The progressive power lens 1 is mounted on the frame 2 with a forward tilt angle of PA. The forward tilt angle PA is an angle formed by the vertical plane QV orthogonal to the line segment Q passing through the fitting point FP and the lens tilt plane QL.
The distance between the inner surface IS of the progressive-power lens 1 and the corneal apex T of the wearer's eyeball E is the corneal apex distance m, and the distance between the corneal apex T of the eyeball E and the rotation center C of the eyeball E. Is the eyeball diameter n.

A region of the light beam L that passes through the progressive addition lens 1 and enters the eyeball E that does not pass through the outer surface OS is defined as an optical non-use region OZ shown on the inner surface side of the shaded portion at the lower end of the lens in FIG. In the first embodiment, the edge OP of the optically unused area OZ is specified by a light ray L that passes through the outer peripheral edge OE where the edge surface RS and the outer surface OS intersect and enters the turning center of the eyeball. . That is, in the first embodiment, the light ray L that passes through the progressive power lens 1 and enters the center of rotation of the eyeball through the point farthest from the fitting point FP is specified, and from the fitting point FP. The most distant point is a point on the outer periphery where the edge surface S and the outer surface OS where the spectacle frame of the progressive addition lens 1 is not fitted are intersected.
The near measurement point NP is set to a position that does not enter the optical non-use area OZ, for example, in FIG. 3, the near measurement point NP is set to a position slightly above the edge OP of the optical non-use area OZ. A progressive end point PE is set above a predetermined dimension, for example, 3 mm.

Next, a method for selecting a spectacle frame according to the first embodiment will be described.
First, the progressive zone length P is determined by the wearer's prescription.
Next, the near measurement point NP is set at a predetermined position below the progressive end point PE that defines the progressive zone length P, for example, at a position 3 mm below the progressive end point PE. In addition, the setting position with respect to the progressive end point PE of the near measurement point NP can be appropriately determined according to the prescription of the wearer and the like, and is not limited to 3 mm.
The optical non-use area OZ is obtained by the ray tracing method so that the near-use measurement point NP does not enter.
In FIG. 3, the ray tracing method calculates what route the light Ln incident on the progressive addition lens 1 follows and where it converges.
For example, a predetermined light beam L ₁ is emitted from the turning center C of the eyeball E toward the progressive addition lens 1 at an angle α ₁ with respect to a horizontal line segment Q passing through the fitting point FP from the turning center C of the eyeball E. , a position passing through the outer surface OS of the light beam L ₁ is to simulate or outer edge OE from lens center side (optical axis side) or the lens outer peripheral side. When the position of the light ray L ₁ passing through the outer surface OS is closer to the lens center than the outer peripheral edge OE, the angle α ₂ (α ₂ > α ₁ ) from the turning center C of the eyeball E toward the progressive addition lens 1. irradiating a predetermined light beam L _2, light L ₂ is passed to the position of the outer surface OS which is a spherical surface to simulate the lens or center side or the lens outward from the outer peripheral edge OE of the outer surface OS. Conversely, when the position of the light ray L ₁ passing through the outer surface OS passes outside the lens from the outer peripheral edge OE, that is, through the edge surface RS, the turning center C of the eyeball E at an angle α ₂ (α ₂ <α ₁ ). Assuming that a predetermined light beam L ₂ is irradiated from the lens to the progressive addition lens 1, whether the position where the light beam L ₂ passes through the spherical outer surface OS is the lens center side or the lens outer side of the outer peripheral edge OE of the outer surface OS. Simulate.

Subsequently, a predetermined light beam Ln is emitted from the turning center C of the eyeball E toward the progressive addition lens 1 at an angle αn (αn = α ₁ , α _2, ... Α _n ). Assuming that the position through which the outer surface OS passes matches the outer peripheral edge OE of the outer surface OS, the position where the light ray Ln passes through the inner surface IS becomes the edge OP of the optical non-use area OZ.
The ray tracing method used in the first embodiment can implement a known technique. In carrying out the ray tracing method, the distance (m + n) from the rotation center C of the eyeball E to the inner surface IS of the lens, the lens refractive index no, the air refractive index na, the spherical refractive power SPH, the curvature RO of the outer surface OS, and the curvature of the inner surface IS. IO, lens center thickness t, addition ADD, astigmatism refractive power C, astigmatism axis Ax, and the like are used.
Furthermore, the same design as other lenses is performed. For example, the distance measurement point EP and the inset B are set according to the wearer's prescription.

When the optical non-use area OZ is set by the ray tracing method, the edge OP is set at a position coincident with the near measurement point NP or a position below the near measurement point NP.
In the first embodiment, a point that exits from the turning center of the eyeball, passes through the near measurement point NP, and passes through the outer surface (a symbol is defined, for example, the minimum frame end OF. When the minimum frame is selected, the outer periphery OE is selected. The eyeglass frame 2 having a frame height that fits within the frame is selected. That is, the distance between the minimum frame end OF and the fitting point FP is the frame minimum FP height dimension FPmin, and the frame upper height Oh defined by the wearer's prescription is added to the frame minimum FP height dimension FPmin. The spectacle frame 2 having a frame top / bottom width larger than the minimum top / bottom dimension (FPmin + Oh) is selected from the spectacle frames having a plurality of frame top / bottom dimensions.

Next, an example actually designed according to the first embodiment will be described.
The progressive zone length P obtained by the wearer's prescription is 14 mm, the distance (m + n) from the turning center C of the eyeball E to the inner surface IS on the eyeball side is 25 mm (12 mm + 13 mm), the lens refractive index no is 1.67, and air refraction The area corresponding to the distance measurement point EP of the curvature na of the outer surface OS is 1.00 (D) and the curvature IO of the inner surface IS is 1.00, the spherical refractive power SPH is −6.00 (D). 7.02 (D), the area corresponding to the near measurement point NP is 5.04 (D), and the addition ADD is 2.00 (D). Assuming that the inset amount B is 2.5 mm, the lens center thickness t is 1.1 mm, the astigmatism refractive power C is 0.00 (D), and the astigmatism axis Ax is 0 degree, the dimension of the minimum vertical width is determined by the forward tilt angle PA. (FPmin + Oh) is as follows. The frame upper height Oh determined by the wearer's prescription or the like is 12 mm.
When the forward tilt angle PA is 10 °, the frame minimum FP height dimension FPmin is 17.68 mm, and the minimum vertical width dimension (FPmin + Oh) is 29.68 mm (17.68 mm + 12 mm). When the forward tilt angle PA is 20 °, the frame minimum FP height dimension FPmin is 17.48 mm, and the minimum vertical width dimension (FPmin + Oh) is 29.48 mm (17.48 mm + 12 mm).
When the minimum vertical width dimension (FPmin + Oh) is obtained, one of the plurality of spectacle frames 2 is selected. For example, if there are eyeglass frames with frame top and bottom widths of 25 mm, 28 mm, and 30 mm, select one with a frame top width larger than the minimum top width dimension (FPmin + Oh) of 29.48 mm, for example, 30 mm To do.

Therefore, in the first embodiment, the following operational effects can be achieved.
(1) Based on the prescription of the wearer when selecting the progressive-power lens 1 having the inner surface IS formed with the progressive region P and the spherical outer surface OS from the plurality of spectacle frames 2 having different frame vertical width dimensions. Assuming that the progressive zone length P is set in advance, the near measurement point NP is set in relation to the progressive end point P of this progressive zone length, and the appropriate frame height is set on the assumption of this near measurement point NP. Select the eyeglass frame. In other words, the progressive zone length P set in the progressive area 13 and defined by the progressive start point PS and the progressive end point PE is determined by the wearer's prescription, and the near-measurement point NP is positioned below the progressive end point PE. In order to prevent the near measurement point NP from entering, an optical non-use region OZ that is a region that does not pass through the outer surface OS among the light rays that pass through the progressive addition lens 1 and enter the eyeball E is set. The optically unused area OZ is obtained by the ray tracing method, and the eyeglass frame 2 having a frame height in which the point where the light passing through the near measurement point from the center of rotation of the eyeball passes through the outer surface falls within the frame is selected. I made it. Therefore, even if the length of the progressive zone length P differs depending on the wearer, the near measurement point NP is set in relation to the progressive end point PE of the progressive zone length P, and the near measurement point NP is optically disabled. In the inner surface progressive lens, the eyeglass frame 2 having a frame height is selected so that the light beam passing through the near measurement point from the center of rotation of the eyeball is positioned outside the use area OZ, and the point passing through the outer surface is within the frame. Sufficient addition can be obtained. In particular, even if the forward tilt angle PA of the progressive addition lens 1 changes and the optical non-use area OZ changes, the optical non-use area OZ is obtained by the ray tracing method, so the spectacle frame 2 corresponding to the wearing condition is selected. can do.

(2) In selecting the spectacle frame 2, the frame minimum FP height dimension FPmin, which is the distance between the frame minimum end OF and the fitting point FP, is obtained, and this frame minimum FP height dimension FPmin is determined by the wearer's prescription and the like. By adding a predetermined frame upper height Oh to the minimum vertical width dimension (FPmin + Oh), the spectacle frame 2 having a frame vertical width larger than the minimum vertical width dimension (FPmin + Oh) is selected from a plurality of frames having different frame vertical widths. I chose one. That is, since the frame upper height Oh determined by the wearer's prescription or the like is used in order to obtain the minimum vertical width dimension, it is not necessary to obtain an optical non-use area for the upper part of the lens. Selection of the spectacle frame 2 can be performed.

(3) The progressive addition lens 1 is attached to the spectacle frame 2 whose upper peripheral portion is fitted to the rim 21. The edge OP of the optical non-use area OZ is fitted with the rim 21. Since this is specified by the light beam Ln that passes outside the outer peripheral edge OE where the edge surface RS and the outer surface OS intersect, only the upper part of the lens is attached to a so-called nyroll frame covered with the rim 21. A sufficient addition can be obtained in the lens.

(4) By using a specified value as the distance (m + n) from the turning center C of the eyeball E to the eyeball side surface, it is possible to easily set the optical non-use area OZ as compared with the actual measurement. Can do.

Next, a second embodiment of the present invention will be described with reference to FIGS.
The second embodiment differs from the first embodiment in the shape of the spectacle frame 3.
FIG. 4 shows the glasses of the second embodiment.
In FIG. 4, the second embodiment is an example of spectacles in which the progressive addition lens 1 is mounted on a spectacle frame 3 such as a metal frame or a cell frame.
The spectacle frame 3 includes a pair of rims 31 each holding the progressive addition lens 1, a bridge 22 connecting the rims 31, a nose pad 23 provided on the nose side of the rim 31, and an ear of the rim 31. And a vine 24 provided on the side.
In the present embodiment, the progressive-power lens 1 has its entire outer peripheral edge fitted in a recess (not shown) of the rim 31.

The schematic configuration of the front surface of the progressive-power lens 1 is almost the same as the configuration shown in FIG. 2, but in this embodiment, the distance from the fitting point FP to the upper edge of the lens including the portion entering the frame. Is the frame upper height Oh, and the distance from the fitting point FP to the lens lower edge including the portion entering the frame is the frame lower height Bh.
FIG. 5 shows an outline in the vertical direction of the progressive addition lens 1 after the lens processing. In FIG. 5, the upper piece 31U and the lower piece 31D of the rim 31 are shown.
In FIG. 5, the progressive-power lens 1 has an inner surface IS on the eyeball side and an outer surface OS on the object side, and an edge surface RS which is an outer peripheral edge and connects the inner surface IS and the outer surface OS. RS, the outer surface OS, and the outer peripheral edge of the inner surface IS are fitted into the upper piece 31U and the lower piece 31D of the rim 31. Therefore, the edge surface RS is not exposed to the outside.
The progressive power lens 1 is mounted on the spectacle frame 3 with a lens tilt angle of PA.

A region that does not pass through the outer surface OS of the light ray L that passes through the progressive addition lens 1 and enters the eyeball E is defined as an optical non-use region OZ. An edge OP of the optical non-use region OZ is In the second embodiment, it is specified by the light beam L that passes outside (in the direction away from the lens center) from the inner peripheral edge FE of the rim 31 of the spectacle frame 3.
The near measurement point NP is set at a position that does not enter the optical non-use area OZ, for example, at the same position as or slightly above the edge OP of the optical non-use area OZ. A progressive end point PE is set on the dimension, for example, 3 mm.

Next, a method for selecting a spectacle frame according to the second embodiment will be described. The design method of the second embodiment is the same as that of the first embodiment.
First, the progressive zone length P is determined by the wearer's prescription, and the near measurement point NP is positioned at a predetermined position below the progressive end point PE that defines the progressive zone length P, for example, at a position 3 mm below the progressive end point PE. Set.
The optical non-use area OZ is obtained by the ray tracing method so that the near-use measurement point NP does not enter.
In the second embodiment, as in the first embodiment, the optically unused area OZ is obtained by the ray tracing method.
That is, as in the first embodiment, a predetermined light beam Ln is emitted from the turning center C of the eyeball E toward the progressive addition lens 1 at an angle αn (αn = α ₁ , α ₂ ... Α _n ). When the position of Ln passing through the outer surface OS coincides with the inner peripheral edge FE of the rim 31 of the spectacle frame 3, the position of the light beam Ln passing through the inner surface IS is the edge OP of the optical non-use area OZ.

When the optical non-use area OZ is set by the ray tracing method, the edge OP is matched with the near-use measurement point NP so that the near-use measurement point NP does not enter the edge OP of the optical non-use area OZ. Alternatively, it is set below the near measurement point NP.
Then, the wearer's prescription or the like is set to the frame minimum FP height dimension FPmin determined by the distance between the point (minimum frame end OF) and the fitting point FP from the center of rotation of the eyeball that passes through the near measurement point. The frame top height Oh defined by the above is added to obtain the minimum vertical width dimension (FPmin + Oh), and one spectacle frame 2 having a frame vertical width larger than the minimum vertical width dimension (FPmin + Oh) is selected from a plurality of frames. .

Next, an example actually designed according to the second embodiment will be described.
The progressive band length P according to the wearer's prescription is 14 mm, the lens refractive index no is 1.67, the air refractive index na is 1.00, the spherical refractive power SPH is 0.00 (D), and the curvature RO of the outer surface OS is 4.00, of the curvature IO of the inner surface IS, the area corresponding to the distance measurement point EP is 4.17 (D), the area corresponding to the near distance measurement point NP is 2.17 (D), and the addition ADD Is 2.00 (D). When the inset amount B is 2.5 mm, the lens center thickness t is 2.0 mm, the astigmatic refractive power C is 0.00 (D), the astigmatic axis Ax is 0 degree, and the forward tilt angle PA is 10 °, the corneal apex The dimension (FPmin + Oh) of the minimum vertical width is as follows according to the distance m.

When the corneal apex distance m is 12 mm, the distance from the turning center C of the eyeball E to the inner surface IS (corner apex distance m + eyeball diameter n) is 25 mm (12 mm + 13 mm). The optical non-use area OZ is set by the ray tracing method, and the frame minimum FP height dimension FPmin, which is the distance between the edge OP and the fitting point FP, is 17.69 mm. If the frame upper height Oh is 12.00 mm depending on prescription and other conditions, the minimum vertical width dimension (FPmin + Oh) is 29.69 mm (17.69 mm + 12 mm).
When the corneal vertex distance m is 17 mm, the distance from the turning center C of the eyeball E to the inner surface IS (corneal vertex distance m + eyeball diameter n) is 30 mm (17 mm + 13 mm). The optical non-use area OZ is set by the ray tracing method, and the frame minimum FP height dimension FPmin, which is the distance between the edge OP and the fitting point FP, is 17.59 mm. If the frame upper height Oh is 12.00 mm depending on prescription and other conditions, the minimum vertical width dimension (FPmin + Oh) is 29.59 mm (17.59 mm + 12 mm).
When the minimum vertical width dimension (FPmin + Oh) is obtained, one of the plurality of spectacle frames 2 is selected. For example, when there are a plurality of types of spectacle frames having a frame top / bottom width of 25 mm, 28 mm, and 30 mm, a frame top / bottom width larger than the minimum top / bottom width dimension (FPmin + Oh), that is, 30 mm is selected.

Therefore, in the second embodiment, the following operational effects can be obtained in addition to the operational effects (1), (2), and (4) of the first embodiment.
(5) The peripheral portion of the entire circumference of the progressive-power lens 1 is fitted to the rim 31 of the spectacle frame 3, and the edge OP of the optically unused area OZ passes through the outside of the inner periphery FE of the rim 31. Since it is specified, the addition power of the progressive-power lens 1 attached to the metal frame or the cell frame, in which the entire peripheral edge of the lens is covered with the rim 31, can be made sufficient.

A third embodiment of the present invention will be described with reference to FIG.
In the third embodiment, the configuration of the progressive-power lens is different from that of the first embodiment.
FIG. 6 is a schematic front view of the progressive-power lens before processing the target lens shape in the third embodiment.
In FIG. 6, the progressive power lens 4 includes a distance area 11 having a refractive power corresponding to far vision, a near area 12 having a refractive power corresponding to near vision, and these distance areas 11. The aspherical lens is provided with a progressive area 13 provided between the intermediate area 12 and intermediate side areas 14 provided on both sides of the progressive area 13. The use area 11 is set to be narrow and the progressive area 13 is set to be wide in order to see an area at the intermediate position.

A main meridian A is formed substantially at the center of the distance region 11, the progressive region 13, and the near region 12.
A distance measurement point DP, which is the center of the distance measurement area, is provided on the main meridian A of the distance area 11, and a center of the near measurement area is above the main meridian A of the near area 12. A near measurement point NP is provided.
The point that the fitting point FP is set on the main meridian A is the same as the first and second embodiments, but the point that the progressive start point PS is set above the fitting point FP is the first and second embodiments. Is different. The distance from the fitting point FP to the lens upper edge is the frame upper height Oh, and the distance from the fitting point FP to the lens lower edge is the frame lower height Bh.

The method for selecting a spectacle frame of the third embodiment is the same as that of the first and second embodiments, but differs from the first and second embodiments in that the distance measurement point is required to be within the upper end of the lens. For example, when the distance measurement point is set at a position 5 mm above the progressive start point, the progressive start point PS needs to be within 5 mm below the upper end of the lens.
First, the progressive zone length P is determined by the wearer's prescription, and the near measurement point NP is positioned at a predetermined position below the progressive end point PE that defines the progressive zone length P, for example, at a position 3 mm below the progressive end point PE. Set.
The optical non-use area OZ is obtained by the ray tracing method so that the near-use measurement point NP does not enter.
In the third embodiment, the spectacle frame 2 having a frame height is selected so that the point passing through the outer surface OS of the light beam passing through the distance measurement point from the center of rotation of the eyeball is within the rims 21 and 31.

In 3rd Embodiment, there can exist an effect similar to 1st, 2 embodiment.
That is,
A ray L that passes through the principal meridian A in the far-field region 11 of the outer surface OS and passes through the center of rotation C of the eyeball E and passes through the point farthest from the fitting point FP is obtained by the ray tracing method. The distance measurement point DP is set at a point closer to the fitting point FP than the point passing through the IS and on the main meridian A on the inner surface IS, and a spectacle frame having a frame height at which this point falls within the frame is selected. Therefore, a spectacle frame having an appropriate frame height can be selected, and a sufficient addition can be obtained in the inner surface progressive lens.
Furthermore, in 3rd Embodiment, there can exist an effect similar to (2) of 1st Embodiment, and (4) of 2nd Embodiment.

Note that the present invention is not limited to the above-described embodiments, and it goes without saying that modifications and improvements within the scope of achieving the objects and effects of the present invention are included in the contents of the present invention. Absent.
For example, in the above-described embodiment, the present invention is applied to the near and middle types of progressive-power lenses 1 and 4, but the present invention can also be applied to near-type and progressive lenses.
Further, in the first embodiment, the progressive power lens 1 in which the upper part is attached to the nyroll type spectacle frame 2 and the lower peripheral edge is exposed has been described. The present invention can also be applied to a progressive-power lens in which is attached to the frame and the upper peripheral edge is exposed.

  The present invention can be used for a progressive-power lens in which a progressive region is formed on the inner surface of the eyeball side.

  DESCRIPTION OF SYMBOLS 1,4 ... Progressive power lens, 2,3 ... Spectacle frame, 11 ... Distance area | region, 12 ... Near area | region, 13 ... Progression area, FP ... Fitting point, P ... Progressive zone length, NP ... Near distance measurement point , DP ... distance measurement point, OZ ... optical non-use area, OP ... edge, PS ... progressive start point, PE ... progressive end point, IS ... inner surface, OS ... outer surface, A ... main meridian

Claims (6)

Select a spectacle frame to which a progressive power lens having a distance region and a near region, an inner surface that is a refractive surface on the eyeball side, and an outer surface that is a refractive surface on the object side and having a progressive region formed on the inner surface is attached. A method,
The progression zone length, which is the length along the main meridian between the progression start point and the progression end point, is determined by the wearer's prescription,
A near-measurement point is set at a point on the inner meridian of the inner surface and closer to the outer peripheral edge of the progressive-power lens than the progressive end point,
The light beam is emitted from the center of rotation of the eyeball, and the light ray passing through the near measurement point passes through the outer surface.
A method for selecting a spectacle frame, comprising: selecting a spectacle frame having a frame height at which this point fits within the frame. In the selection method of the spectacles frame described in Claim 1,
The progressive power lens, a part of the periphery thereof is fitted into the inner peripheral recess of the spectacle frame,
A ray that passes through the main meridian in the near-field region of the outer surface and passes through the center of the eyeball and is farthest from the fitting point is a cover where the spectacle frame of the progressive-power lens is not fitted. A method for selecting a spectacle frame, wherein the surface is a point on an outer peripheral edge where the surface and the outer surface intersect. In the selection method of the spectacles frame described in Claim 1,
The progressive power lens, the peripheral portion of the entire circumference is fitted in the inner peripheral concave portion of the spectacle frame,
A ray passing through the main meridian in the near-field region of the outer surface and passing through the center of the eyeball, the point farthest from the fitting point is on a line where the inner peripheral edge of the spectacle frame intersects the outer surface A method for selecting a spectacle frame. In the selection method of the spectacles frame described in Claim 1,
A light ray passing through the main meridian in the far-field region of the outer surface and passing through the center of the eyeball and passing through the point farthest from the fitting point, and
A distance measurement point is set at a point on the main meridian on the inner surface that is closer to the fitting point than a point where the light ray passes through the inner surface,
The light beam is emitted from the center of rotation of the eyeball, and the light ray passing through the distance measurement point is passed through the outer surface to obtain the point by the light ray tracing method.
A method for selecting a spectacle frame to which a progressive addition lens is attached, characterized in that this point falls within the frame. In the selection method of the spectacles frame described in Claim 4,
The progressive power lens, a part of the periphery thereof is fitted into the inner peripheral recess of the spectacle frame,
A ray passing through the main meridian in the far-field region of the outer surface and passing through the center of the eyeball, the point farthest from the fitting point is not fitted with the eyeglass frame of the progressive-power lens A method for selecting a spectacle frame, comprising a certain point on an outer peripheral edge where an edge surface and the outer surface intersect. In the selection method of the spectacles frame described in Claim 4,
The progressive power lens, the peripheral portion of the entire circumference is fitted in the inner peripheral concave portion of the spectacle frame,
A ray that passes through the main meridian in the far-field region of the outer surface and passes through the center of the eyeball, the point farthest from the fitting point is on the line where the inner periphery of the spectacle frame intersects the outer surface A method for selecting a spectacle frame, comprising:

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