JP5822482B2 - Eyeglass lenses - Google Patents

Description

  The present invention relates to a spectacle lens.

  In Patent Document 1, in a progressive multifocal lens used for a spectacle lens suitable for correction of visual acuity such as presbyopia, a progressive refracting surface that is conventionally added to the object side surface is provided on the eyeball side surface. Have been described. As a result, the object-side surface can be a spherical surface with a constant base curve, so it is possible to prevent fluctuations due to the shape factor of the magnification, and to reduce the magnification difference between the distance portion and the near portion, Moreover, the change of the magnification of the progressive part can be suppressed. Therefore, it is possible to provide a progressive multifocal lens that can reduce image shaking and distortion due to a difference in magnification and can provide a comfortable field of view. Further, in Patent Document 1, it is possible to synthesize a progressive refracting surface and a toric surface for correcting astigmatism with a surface on the eyeball side by using a synthesis formula, and even in a progressive multifocal lens for correcting astigmatism, the image shakes. And that distortion can be reduced.

  In Patent Document 2, in a multifocal lens for spectacles having a field portion having different refractive powers such as a distance portion and a near portion, the average surface refractive power of the distance portion on the object side surface and the average of the near portion The difference in surface refracting power is mathematically smaller than the addition, and a predetermined addition is provided by adjusting the average surface power of the distance portion and the average surface power of the near portion of the eyeball side surface. Providing a multifocal lens for a pair of spectacles is described. It is possible to adjust the average surface refractive power of the object side surface so that the magnification difference between the distance portion and the near portion is small, and to reduce the difference in average surface power of the object side surface. Is possible. Therefore, it is possible to provide a multifocal lens that has less image shake and distortion due to a difference in magnification, and has a wide clear vision area with improved astigmatism and a comfortable field of view with less image shake.

  Patent Document 3 discloses a double-sided aspherical progressive power that reduces the magnification difference between the distance portion and the near portion, provides a good visual acuity correction with respect to the prescription value, and provides a wide effective field of view with little distortion during wearing. Providing a lens is described. Therefore, in Patent Document 3, on the first refracting surface of the object side surface, the horizontal surface power and the vertical surface power at the distance power measurement position F1 are DHf and DVf, respectively. In the refracting surface, when the horizontal surface refractive power and the vertical surface refractive power at the near power measurement position N1 are DHn and DVn, respectively, the relational expressions DHf + DHn <DVf + DVn and DHn <DVn are satisfied. At the same time, the surface astigmatism components at F1 and N1 of the first refractive surface are canceled by the second refractive surface of the eyeball side surface, and the first and second refractive surfaces are combined and based on the prescription value. It is described that the distance power and the addition power are given.

  Patent Document 4 describes that a progressive-power lens capable of reducing image distortion and blur inevitably generated in a progressive-power lens and improving the wearing feeling can be provided. For this reason, in Patent Document 4, a double-sided progressive lens is used in which both the outer surface and the inner surface are progressive surfaces, and the addition of the surface of the outer surface is negative, so that the average surface refractive power distribution of the outer surface and the inner surface is similar. Design the surface shape.

International Publication No. W097 / 19382 International Publication No. W097 / 19383 JP 2003-344813 A JP 2004-004436 A

  Although these techniques have improved the performance, there are still users who cannot adapt to the characteristics of the progressive power lens, particularly the fluctuation, and further improvement is required.

One aspect of the present invention is a progressive-power lens for spectacles including a distance portion and a near portion having different powers, and is provided on a surface on the object side along a vertical reference line passing through a main gaze line or a fitting point. Horizontal surface refractive power OMHP (y), vertical surface refractive power OMVP (y) of the object side surface, horizontal surface refractive power absolute value IMHP (y) of the eyeball side surface, and eyeball This is a progressive power lens in which the absolute value IMVP (y) of the surface refractive power in the vertical direction of the side surface satisfies the following conditions.
OMHP (y)> OMVP (y) (1)
IMHP (y)> IMVP (y) (2)
OMHP (y) -OMVP (y) = IMHP (y) -IMVP (y) (3)
However, these conditions and the following conditions do not include astigmatism prescription. That is, these conditions do not include the astigmatism prescription in the distance prescription. Moreover, y is a coordinate along the main gaze line or the vertical reference line.

  This progressive-power lens is a toric surface (also called a toroidal surface) along a vertical reference line (both also called a main meridian) passing through at least a main gaze line or a fitting point on both the object side surface and the eyeball side surface. ) Element. The toric surface elements of both the object side surface and the eyeball side surface each have a larger curvature in the horizontal direction (horizontal direction) than the curvature in the vertical direction (vertical direction). That is, the radius of curvature in the longitudinal direction is larger than the radius of curvature in the lateral direction, and the shift of the surface refractive power due to the elements of these toric surfaces is canceled by the elements of both toric surfaces. Therefore, these toric surface elements are not intended to correct astigmatism, but are effective in suppressing the fluctuation of the image through the spectacle lens accompanying the movement of the eye (line of sight). The typical movement of the line of sight (eye) when the image obtained through the spectacle lens is shaken is due to the movement of the eyeball (line of sight) relative to the head by the vestibulo-oculomotor reflex that compensates for the movement of the head. Is. The range of movement of the line of sight due to vestibulo-oculomotor reflection is generally wide in the horizontal direction (lateral direction). Therefore, by introducing a toric surface element whose horizontal surface power is larger than the vertical surface power on the object side surface and the eyeball side surface, the line of sight moves when the line of sight moves in the horizontal direction. It is possible to suppress fluctuations in angles passing through the spectacle lens (incidence angle and exit angle of the line of sight with respect to the spectacle lens surface). Therefore, various aberrations of the image obtained through the eyeglass lens when the line of sight is moved can be reduced. Therefore, it is possible to provide a spectacle lens with little image fluctuation obtained through the spectacle lens.

The condition (3) is a conditional expression when the lens thickness is small, and is generally a conditional expression (3a) that takes into account the shape factor (shape factor) that takes into account the lens thickness used for calculating the refractive power of the spectacle lens. ) Is as follows.
IMHP (y) -IMVP (y) =
OMHP (y) / (1-t / n * OMHP (y))-OMVP (y) /
(1-t / n * OMVP (y)) (3a)
Therefore, it is also effective to use the condition (3a) instead of the condition (3). Here, t is the thickness of the progressive-power lens, and n is the refractive index of the base material of the progressive-power lens.

  Also, in order to perform the y-coordinates of the conditions (3) and (3a) more accurately, in the lens peripheral portion, the deviation of the transmission position of the line of sight on the lens on the outer surface side and the inner surface side is determined by ray tracing. It is also possible to apply for it.

  The method of manipulating the surface refractive power on the eyeball side (inner surface side) to cancel the toric surface element applied to the object side (outer surface) considers the thickness of the lens and the detailed path of the light beam that passes through the lens. However, the object can be almost achieved by the condition (3).

The progressive power lens preferably further satisfies the following conditions.
OMHP (y) -OMVP (y) = IMHP (y) -IMVP (y) = C0
... (4)
However, C0 is a constant and desirably satisfies the following range.
1 (D) <C0 <6 (D) (5)
However, the unit D is diopter.
The constant C0 further preferably satisfies the following range.
1 (D) <C0 <4 (D) (5 ′)

  A progressive power lens having a surface in which the difference in surface power in the vertical direction (longitudinal direction) with respect to the surface power in the horizontal direction (lateral direction) is constant is relatively easy to manufacture. Therefore, it is possible to provide a progressive power lens with low vibration and low vibration.

  In the progressive-power lens described above, it is desirable that the surface on the eyeball side is a progressive surface. It is possible to provide a spectacle lens with little change in the magnification of an image obtained through the spectacle lens and less distortion.

Further, the progressive-power lens described above has a horizontal surface power OHP (y) of the object-side surface within a range of ± 10 mm across the main gaze line or vertical reference line, and a vertical direction of the object-side surface. The surface refractive power OVP (y) of the eyeball side, the absolute value IHP (y) of the horizontal surface power of the eyeball side surface, and the absolute value IVP (y) of the vertical surface power of the eyeball side surface are It is desirable to satisfy the following conditions.
OHP (x, y)> OVP (x, y) (6)
IHP (x, y)> IVP (x, y) (7)
OHP (x, y) -OVP (x, y) = IHP (x, y) -IVP (x, y) = C0
... (8)
Where x is the coordinate of a horizontal reference line passing through the fitting point.

  As a human visual characteristic when using a progressive-power lens, the frequency of use on the main gazing line is extremely high, and the image is felt when the visual work is performed using the vicinity of the main gazing line. Accordingly, if the horizontal surface power OHP is shifted in the intensity direction by at least ± 10 mm in the horizontal direction around the main line of sight, the effect of reducing image fluctuation can be sufficiently obtained.

In the progressive-power lens described above, it is more preferable that the following condition is satisfied within a range of ± 10 mm across the main gaze line or the vertical reference line.
OHP (x, y) = C1 (9)
OVP (x, y) = C2 (10)
However, C1 and C2 are constants.

  A region sandwiching the main line of sight or vertical reference line on the object side surface can be constituted by a relatively simple toric surface having a constant surface refractive power in the horizontal direction and a surface refractive power in the vertical direction. Therefore, it is possible to provide progressive refractive power with less fluctuation at lower cost. A typical progressive-power lens is a progressive-power lens in which the object side surface is a toric surface.

  One of the different aspects of the present invention is spectacles having the progressive power lens described above and a spectacle frame to which the progressive power lens is attached.

Furthermore, one of the different aspects of the present invention is a method for designing a multifocal lens for spectacles including a distance portion and a near portion having different powers, and includes the following steps.
The horizontal surface power OMHP (y) of the object side surface along the vertical reference line passing through the main gaze line or fitting point, the surface power OMVP (y) of the object side surface in the vertical direction, and the eyeball The absolute value IMHP (y) of the surface refractive power in the horizontal direction of the side surface and the absolute value IMVP (y) of the surface refractive power in the vertical direction of the surface on the eyeball side are expressed by the above conditions (1) to (3). Choose to meet.

  Further, the selecting step includes selecting to satisfy the condition (4), the conditions (6) to (8), and the conditions (9) and (10). It is effective.

The perspective view which shows an example of spectacles. FIG. 2A is a plan view schematically showing one of the progressive-power lenses, and FIG. 2B is a cross-sectional view thereof. 3A is a diagram showing an equivalent spherical power distribution of a spectacle lens, FIG. 3B is a diagram showing an astigmatism distribution of the spectacle lens, and FIG. 3C is a distortion when a square lattice is viewed. FIG. The figure which shows a vestibule movement reflex. The figure which shows the maximum angle of vestibulo-oculomotor reflex. The figure which shows a mode that a rectangular pattern is set. The figure which overlaps and shows the geometric shift | offset | difference of a rectangular pattern. The figure which shows the change of the inclination of the grid line of a rectangular pattern. The figure which shows the variation | change_quantity of the grid line of the horizontal direction of the grid line of a rectangular pattern. The figure which shows the variation | change_quantity of the grid line of the perpendicular direction of the grid line of a rectangular pattern. 11A is a diagram showing the surface refractive power on the main gaze line of the outer surface of the progressive-power lens of Example 1, and FIG. 11B is the surface on the main gaze line of the inner surface of the progressive-power lens of Example 1. FIG. The figure which shows refractive power. 12A is a diagram showing the surface refractive power on the main gaze line of the outer surface of the progressive-power lens of Comparative Example 1, and FIG. 12B is the surface of the inner surface of the progressive-power lens of Comparative Example 1 on the main gaze line. The figure which shows refractive power. 13A shows the surface astigmatism distribution on the outer surface of the progressive-power lens of Example 1, and FIG. 13B shows the surface astigmatism distribution on the outer surface of the progressive-power lens of Comparative Example 1. Figure. FIG. 14 (a) shows a spherical equivalent surface power distribution of the outer surface of the progressive addition lens of Example 1, FIG. 14 (b) spherical equivalent surface power distribution of the outer surface of the progressive addition lens of Comparative Example 1 FIG. FIG. 15A is a diagram showing the surface astigmatism distribution on the inner surface of the progressive addition lens of Example 1, and FIG. 15B is the surface astigmatism distribution on the inner surface of the progressive addition lens of Comparative Example 1. Figure. FIG. 16 (a) shows a spherical equivalent surface power distribution of the inner surface of the progressive addition lens of Example 1, FIG. 16 (b) spherical equivalent surface power distribution of the inner surface of the progressive addition lens of Comparative Example 1 FIG. FIG. 17A is a diagram showing the astigmatism distribution of the progressive-power lens of Example 1, and FIG. 17B is a diagram showing the astigmatism distribution of the progressive-power lens of Comparative Example 1. 18A is a diagram showing an equivalent spherical power distribution of the progressive-power lens of Example 1, and FIG. 18B is a diagram showing an equivalent spherical power distribution of the progressive-power lens of Comparative Example 1. The figure which shows a vibration (vibration parameter | index IDd). The figure which shows deformation | transformation amount (vibration index IDs). 21A is a diagram showing the surface refractive power on the main gaze line of the outer surface of the progressive-power lens of Example 2, and FIG. 21B is the surface on the main gaze line of the inner surface of the progressive-power lens of Example 2. FIG. The figure which shows refractive power. 22A is a diagram showing the surface refractive power on the main gaze line of the outer surface of the progressive-power lens of Comparative Example 2, and FIG. 22B is the surface of the inner surface of the progressive-power lens of Comparative Example 2 on the main gaze line. The figure which shows refractive power. FIG. 23A is a diagram showing the surface astigmatism distribution on the outer surface of the progressive-power lens of Example 2, and FIG. 23B is the surface astigmatism distribution on the outer surface of the progressive-power lens of Comparative Example 2. Figure. Figure 24 (a) is a view showing an equivalent spherical surface power distribution of the outer surface of the progressive addition lens of example 2, FIG. 24 (b) is an equivalent spherical surface power distribution of the outer surface of the progressive addition lens of Comparative Example 2 FIG. FIG. 25A is a diagram showing the surface astigmatism distribution on the inner surface of the progressive-power lens of Example 2, and FIG. 25B is the surface astigmatism distribution on the inner surface of the progressive-power lens of Comparative Example 2. Figure. Figure 26 (a) is a view showing an equivalent spherical surface power distribution of the inner surface of the progressive addition lens of example 2, FIG. 26 (b) is an equivalent spherical surface power distribution of the inner surface of the progressive addition lens of Comparative Example 2 FIG. FIG. 27A is a diagram showing the astigmatism distribution of the progressive addition lens of Example 2, and FIG. 27B is a diagram showing the astigmatism distribution of the progressive addition lens of Comparative Example 2. FIG. 28A is a diagram showing an equivalent spherical power distribution of the progressive-power lens of Example 2, and FIG. 28B is a diagram showing an equivalent spherical power distribution of the progressive-power lens of Comparative Example 2. The figure which shows a vibration (vibration parameter | index IDd). The figure which shows deformation | transformation amount (vibration index IDs). The flowchart which shows the process of design and manufacture of a progressive-power lens.

  FIG. 1 is a perspective view showing an example of eyeglasses. FIG. 2A schematically shows one lens of one progressive-power lens according to the embodiment of the present invention in a plan view. FIG. 2B schematically shows one of the progressive-power lenses in a cross-sectional view.

  In this example, as viewed from the user side (user side, wearer side, eyeball side), the left side is described as left and the right side is described as right. The spectacles 1 includes a pair of left and right spectacle lenses 10L and 10R for the left eye and right eye, and a spectacle frame 20 on which the lenses 10L and 10R are respectively mounted. The spectacle lenses 10L and 10R are progressive power lenses, more specifically, progressive multifocal lenses (progressive power lenses). Each of the lenses 10L and 10R is a meniscus lens having a basic shape convex toward the object side. Therefore, each of the lenses 10L and 10R includes an object side surface (convex surface, also referred to as an outer surface) 19A and an eyeball side (user side) surface (a concave surface, also referred to as an inner surface) 19B.

  FIG. 2A shows the right-eye lens 10R. This lens 10R includes a distance portion 11 that is a visual field portion for viewing a long distance object (distant vision) upward, and a short distance object having a different power (refractive power) from the distance portion 11 below. It includes a near vision portion 12 which is a visual field portion for viewing (near vision). Further, the lens 10R includes an intermediate portion (a portion for intermediate vision, a progressive portion, a progressive zone) that connects the distance portion 11 and the near portion 12 so that the refractive power continuously changes. The lens 10 </ b> R includes a main gazing line (also referred to as a main meridian) 14 that connects a position on the lens that is the center of the visual field when performing far vision, intermediate vision, and near vision. The fitting point Pe, which is a reference point on the lens that allows the line of sight in the far horizontal front view (first eye position) to pass when the outer periphery of the spectacle lens 10R is formed and framed with the frame, is a distant point. Usually, it is located at the lower end of the working part 11. In the following, this fitting point Pe is set as the coordinate origin of the lens, the horizontal coordinate is set as the X coordinate, and the vertical coordinate is set as the Y coordinate. The main gazing line 14 extends substantially perpendicularly from the distance portion 11 toward the near portion 12 and bends to the nose side after passing the fitting point Pe with respect to the Y coordinate.

  In the following description, the spectacle lens 10R for the right eye is mainly described as the spectacle lens. However, the spectacle lens, the spectacle lens, or the lens may be the spectacle lens 10L for the left eye. The eyeglass lens 10L is basically symmetrical to the right eyeglass lens 10R except for the difference in spectacle specifications between the left and right eyes. In the following description, the right-eye and left-eye spectacle lenses 10R and 10L are commonly referred to as spectacle lenses (or lenses) 10.

Of the optical performance of the progressive power lens 10, the width of the field of view can be known from an astigmatism distribution diagram and an equivalent spherical power distribution diagram. One of the performances of the progressive-power lens 10 is that the vibration (sway) that is felt when the head is moved while wearing the progressive-power lens 10 is important, and astigmatism distribution and equivalent spherical power distribution are almost all. Even if they are the same, a difference may occur with respect to the wobble. In the following, first, an evaluation method for fluctuation will be described, and the results of comparison between the embodiment of the present application and a conventional example will be shown using the evaluation method.

1. FIG. 3A shows an equivalent spherical power distribution (unit: diopter (D)) of a typical progressive-power lens 10, and FIG. 3B shows an astigmatism distribution (unit: diopter). (D)) is shown, and FIG. 3C shows a state of distortion when the square lattice is viewed by the lens 10. In the progressive-power lens 10, a predetermined power is added along the main gaze line 14. Therefore, due to the addition of the power, a large astigmatism is generated on the side of the intermediate region (intermediate portion, progressive region) 13, and the object appears blurred in that portion. In the equivalent spherical power distribution, the power is increased by a predetermined amount in the near portion 12, and the power is sequentially decreased to the intermediate portion 13 and the distance portion 11. In the progressive-power lens 10, the power of the distance portion 11 (distance power, Sph) is 3.00D (diopter), and the addition power (ADD) is 2.00D.

  Due to the difference of the power depending on the position on the lens 10, the magnification of the image in the near portion 12 having a large power is larger than that in the distance portion 11, and from the intermediate portion 13 to the side of the near portion 12, the square lattice image is Looks distorted. This causes the image to sway when the head is moved.

  FIG. 4 shows an overview of vestibulo-ocular reflex (VOR). When a person looks at things, his head moves and his field of view moves. At this time, the image on the retina also moves. If there is a movement (eye rotation (rotation)) 7 of the eyeball 3 that cancels out the movement of the head (face rotation (rotation), head rotation) 8, the line of sight 2 becomes stable (does not move), The retinal image does not move. Such a reflexive eye movement having a function of stabilizing the retinal image is called compensatory eye movement. One of the compensatory eye movements is the vestibulo-oculomotor reflex, and the head rotation stimulates the reflex. The neural mechanism of vestibulo-oculomotor reflex by horizontal rotation (horizontal rotation, horizontal rotation) has been elucidated to some extent, the horizontal semicircular canal detects head rotation 8, and the input from it acts on the extraocular muscles to suppress and excitability It is considered that the eyeball 3 is moved.

  When the head rotates, the retinal image does not move when the eyeball rotates due to the vestibulo-oculomotor reflex, but the spectacle lens 10 rotates in conjunction with the rotation of the head as shown by the broken line and the alternate long and short dash line in FIG. For this reason, the line of sight 2 that passes through the spectacle lens 10 moves relatively on the spectacle lens 10 due to vestibular movement reflection. Therefore, if there is a difference in the imaging performance of the eyeglass lens 10 in the range in which the eyeball 3 moves due to the vestibular movement reflection, that is, the range in which the line of sight 2 passes due to the vestibular movement reflection, the retinal image may be distorted.

  FIG. 5 shows an example of observing the head position (eye position) movement during target search. Several graphs shown in FIG. 5 show how much the head turns to recognize a target (object) moved by an angle in the horizontal direction from the point of gaze. In a gaze state in which the target (object) is focused, as shown in the graph 41, the head rotates with the object. On the other hand, in a discriminating state where the target (object) is simply recognized, the movement of the head is about 10 degrees smaller than the angle (movement) of the object as shown in the graph 42. (Less). Based on this observation result, the limit of the range in which the object can be recognized by the movement of the eyeball can be set to about 10 degrees. Therefore, when a human moves the head in a natural state and sees an object by the vestibulo-oculomotor reflex, the horizontal rotation angle of the head is about 10 degrees to the left and right (the maximum horizontal movement of the eyeball 3 by the vestibulo-oculomotor reflex). The angle θxm).

  On the other hand, the maximum rotation angle of the head in the vertical direction when viewing an object by vestibulo-oculomotor reflection is a change in power in the middle part in the case of a progressive-power lens. Since the degree is not suitable and the image is blurred, it can be considered to be smaller than that in the horizontal direction. From the above, it is preferable to use a head rotation angle, which is a parameter in the case of simulation of shaking, of about 10 degrees horizontally in the horizontal direction and smaller in the vertical direction, for example, about 5 degrees up and down. In addition, it can be seen that a typical value of the range in which the line of sight moves due to the vestibular movement reflection is about ± 10 degrees to the left and right of the main gazing line 14 in the horizontal direction.

  FIG. 6 shows a state in which a visual simulation is performed in consideration of the vestibulo-oculomotor reflex when the head is rotated with respect to the observation target arranged in the virtual plane 59 of the virtual space, in this example, the rectangular pattern 50. ing. With the rotation center Rc of the eyeball 3 as the origin in the virtual space, the z axis is set in the horizontal front direction, the x axis is set in the horizontal direction, and the y axis is set in the vertical direction. A rectangular pattern 50 of the observation target is arranged on a virtual plane 59 separated by a distance d in a direction that forms an angle θx with respect to the yz plane and an angle θy with respect to the xz plane.

In the present example, the rectangular pattern 50 is a square lattice that is divided into two halves in the vertical and horizontal directions. A grid line 52, a center horizontal grid line 53 passing through the geometric center 55 , and upper and lower horizontal grid lines 54 that are symmetrical with respect to the center horizontal grid line 53 are included. The distance d between the virtual plane 59 and the eyeball 3 is adjusted so that the square pattern 50 of the square lattice is set with the viewing angle on the spectacle lens 10 as shown below.

  In this example, the spectacle lens 10 is placed in front of the eyeball 3 at the same position and posture as when actually worn, and the vicinity of the maximum horizontal angle θxm in which the eyeball 3 moves by the vestibular eye movement reflection with respect to the gazing point, that is, the gazing point. The virtual plane 59 is set so that the left and right vertical grid lines 52 and the upper and lower horizontal grid lines 54 can be seen at ± 10 degrees.

The size of the rectangular lattice 50 of the square lattice can be defined by the viewing angle, and can be set according to the object to be viewed. For example a mobile PC field pitch of the grating is such screen is small, field pitch of the grating in the object, such as a screen desktop PC can be increased.

  On the other hand, regarding the distance d to the observation target (virtual surface) 59, in the case of the progressive-power lens 10, the distance of the observation object assumed by the distance portion, the intermediate portion, and the near portion changes. Considering the above, it is appropriate to set a distance of several meters or more for the distance portion, a short distance of about 40 to 30 cm for the near portion, and an intermediate distance of about 1 to 50 cm for the intermediate portion. However, for example, when walking, the intermediate part and the near part also have a distance of 2 m to 3 m to be observed, so it is not necessary to set the distance d so strictly according to the far / middle / near area on the lens. The influence on the calculation result of the fluctuation index is not significant.

  The rectangular pattern 50 as the target object is observed in the viewing angle direction deviated from the viewing direction (θx, θy) by the lens refraction action. An observation image of the rectangular pattern 50 at this time can be obtained by a normal ray tracing method. Based on this state, when the + α ° head is rotated in the horizontal direction, the lens 10 is also rotated + α ° together with the face. At this time, the eyeball 3 rotates in the opposite direction by α °, that is, −α ° due to the vestibulo-oculomotor reflection, so that the geometrical shape of the rectangular pattern 50 of the target object is determined using the position where the line of sight 2 is moved by −α ° on the lens 10. You will see the center 55. Therefore, since the transmission point of the line of sight 2 of the lens 10 and the incident angle of the line of sight 2 to the lens 10 change, the rectangular pattern 50 as the target object is observed in a different form.

  For this reason, when the head is repeatedly rotated left and right or up and down, images of the observation target (rectangular pattern) 50 at both ends of the maximum or predetermined rotation angle θx1 are superimposed on the geometric center 55 of the observation target, The geometrical difference between the two shapes is calculated. An example of the horizontal angle θx1 is the maximum horizontal angle θxm (about 10 degrees) at which the eyeball 3 moves due to vestibulo-oculomotor reflection.

  One index used for the evaluation of the fluctuation is the fluctuation index IDd, and the fluctuation index IDd is used to calculate the change in the inclination of the horizontal grid lines 53 and 54 and the vertical grid lines 51 and 52. The swing index IDs is used to calculate the moving area of the horizontal grid lines 53 and 54 and the vertical grid lines 51 and 52.

  FIG. 7 shows an example of an image of the rectangular pattern 50 when the eyeball 3 and the rectangular pattern 50 are moved to the left and right at the first horizontal angle (swing angle) θx1 (10 degrees) with respect to the gazing point. In this state, when the spectacle lens 10 is moved left and right together with the head at a horizontal angle (swing angle) of 10 degrees, the line of sight 2 does not move from the geometric center 55 of the rectangular pattern 50 without moving the rectangular pattern 50. Corresponds to the state of viewing the rectangular pattern 50. The rectangular pattern 50a (broken line) is an image (right rotation image) observed through the eyeglass lens 10 by the ray tracing method at a swing angle of 10 °, and the rectangular pattern 50b (solid line) is similarly at a swing angle of −10 °. It is an image to be observed (left-rotated image), and the rectangular patterns 50a and 50b are overlapped so that the geometric center 55 coincides. Incidentally, the image of the rectangular pattern 50 observed at the swing angle of 0 ° is located approximately in the middle thereof. Images observed when the swing angle is set up and down (upper rotation image and lower rotation image) can be similarly obtained.

  These images (rectangular patterns) 50a and 50b are images of the target object that the user actually obtains when the user shakes his / her head while viewing the observation target through the eyeglass lens 10, and these images 50a and 50b. This difference (deformation) can be regarded as representing the movement of the image when the head is shaken.

  FIG. 8 shows the swing index (swing index) IDd. The fluctuation index IDd is a change in the inclination of each of the grid lines 51 to 54. As shown in FIG. 8, twelve fluctuation indices IDd can be obtained by geometrically calculating the amount of change in the gradient of each side (grid line) 51 to 54 of the rectangular pattern 50. Of these, the amount of change in the gradient of the horizontal grid lines 53 and 54 represents “undulation”, and the amount of change in the gradient of the vertical grid lines 51 and 52 represents “fluctuation”. Therefore, when the amount of change in the gradient of the grid lines 51 to 54 is summed for each direction, the fluctuation can be quantitatively evaluated as “a feeling of undulation” and “a feeling of fluctuation”, respectively.

  9 and 10 show the swing index (swing index) IDs. The fluctuation index IDs is a different index used for the evaluation of the fluctuation, and is a magnitude of deformation of the overall shape of the rectangular pattern 50. 9 and 10, twelve numerical values can be obtained by geometrically calculating the amount of movement of each of the grid lines 51 to 54 of the rectangular pattern 50 as an area as shown in FIGS. FIG. 9 shows the amount of movement (hatched area) of the grid lines 53 and 54 in the horizontal direction, and FIG. 10 shows the amount of movement (hatched area) of the grid lines 51 and 52 in the vertical direction. The shake index IDs represented by the movement amount (area) shows the same tendency as the shake index IDd represented by the change amount of the previous gradient, but when the lens 10 has a large magnification change near the shake evaluation position, for example, When there is a deformation that causes expansion and contraction in the horizontal direction, the index includes these elements.

  These fluctuation indices IDd and IDs can be properly used as horizontal components, vertical components, and their combined values depending on the application. Hereinafter, the fluctuation index IDd obtained from the change in gradient may be expressed as “vibration”, and the fluctuation index IDs obtained from the movement amount of the grid line may be expressed as “deformation amount”.

  The unit of the “vibration” fluctuation index IDd is dimensionless because it is the amount of change in the gradient of each grid line on the viewing angle coordinates. On the other hand, the unit of the deflection index IDs of the “deformation amount” is an area on the viewing angle coordinate, and is a square of the degree. Note that the deformation index IDs due to the deformation amount can be made dimensionless by dividing the area of the change amount by the area at 0 degrees before adding the head rotation, and can be displayed as a ratio (for example, percentage). is there.

  The index IDd relating to the vibration is “horizontal @CL” for the lattice line 53 in the horizontal direction and “vertical @CL” for the lattice line 51 in the vertical direction among the vibrations of the center lattice lines 51 and 53. As an index. Further, the vibrations of all the horizontal lattice lines 53 and 54 including the central lattice line 53 are “horizontal L”, and the vibrations of all the vertical lattice lines 51 and 52 are “vertical L”. The total or average of the vibration of the grid lines is indexed as “all L”.

  Since “horizontal @CL” and “vertical @CL” are easy and simple to calculate, it is convenient when calculating over the entire surface of the lens 10 and mapping it. On the other hand, “horizontal L” and “vertical L” are not only fluctuations of a single horizontal or vertical line when a person (user) actually feels shaking, but also an outline of an object captured as a shape. From the fact that fluctuations are perceived at the same time, it can be said that the index is closer to the user's sense.

  Further, since the user perceives both the horizontal direction and the vertical direction at the same time, “total L” obtained by adding them is the most appropriate index. However, there is a possibility that the susceptibility to “waving” and “fluctuation” differs depending on the user, and the use of the gaze according to the individual's living environment often causes the movement of the gaze in the horizontal direction, and “waving” is a problem. Conversely, there may be cases where “fluctuation” is a problem. Therefore, it is also useful to index and evaluate the fluctuation by each direction component.

  For the index IDs relating to the deformation amount, the fluctuation area of all the horizontal grid lines 53 and 54 is “horizontal L”, the fluctuation area of all the vertical grid lines 51 and 52 is “vertical L”, and the sum of them is “all L”. As an index. The necessity for indexing for each component and the indexing by summation are the same as those for the vibration described above. The merit of the index IDs based on the deformation amount is that a change in magnification is taken into account. In particular, in the case of the progressive-power lens 10, power is added in the vertical direction. For this reason, when the user sees his / her neck swinging in the vertical direction, there is a phenomenon that the image is enlarged or reduced due to a change in the frequency, or the image appears to swing back and forth. In addition, even when the addition power is large, the phenomenon that the magnification decreases at the side of the near portion becomes remarkable. For this reason, expansion and contraction in the lateral direction of the image occur. The index IDs based on the deformation amount is useful as an evaluation method because these changes can be quantified.

2. Embodiment 1
2.1 Example 1
FIG. 11A shows the horizontal surface power (surface power) OMHP (y) along the main gaze line 14 of the outer surface (object-side surface) 19A of the progressive-power lens 10a of Example 1 and the vertical direction. The surface refractive power (surface refractive power) OMVP (y) in the direction is shown in units of diopters (D). FIG. 11B shows a horizontal surface power (surface power) IMHP (y) along the main line of sight 14 of the inner surface (eyeball side) 19B of the progressive power lens 10a, and a surface in the vertical direction. The refractive power (surface refractive power) IMVP (y) is shown in units of diopters (D). Although the surface power IMHP (y) of the inner surface 19B and the surface power IMVP (y) in the vertical direction are originally negative values, in this specification, the surface power of the inner surface 19B is an absolute value. Show. The same applies to the following. The y coordinate is the coordinate of a vertical reference line with the fitting point Pe as the origin. The x coordinate described below is a coordinate of a horizontal reference line perpendicular to a horizontal reference line perpendicular to the vertical reference line with the fitting point Pe as an origin. The main gazing line (main meridian) 14 is converging from the nose with respect to the vertical reference line, but the y coordinate is used as a coordinate.

In this progressive-power lens 10a, in the horizontal transmission refractive power (power) HP and the vertical transmission refractive power (power) VP along the main line of sight 14, the line of sight 2 is applied to each surface 19A and 19B of the lens 10a. On the other hand, HP and VP can be approximately obtained by the following equations if they are perpendicular to each other.
HP (y) = OMHP (y) -IMHP (y) (11)
VP (y) = OMVP (y) -IMVP (y) (12)

Here, the expressions (11) and (12) are relational expressions when the thickness of the lens is small, and a shape factor (shape factor) considering the lens thickness generally used for calculating the refractive power of the spectacle lens is taken into account. It is also possible to replace with the relational expression. In that case, the following equations (11a) and (12a) are obtained.
HP (y) = OMHP (y) / (1-t / n * OMHP (y))-IMHP (y)
... (11a)
VP (y) = OMVP (y) / (1-t / n * OMVP (y))-IMVP (y)
... (12a)
Here, t is the lens thickness (unit: meter), n is the refractive index of the lens material. Further, in order to perform the y-coordinates of the expressions (11), (11a), (12), and (12a) more accurately, the outer surface side and the inner surface of the transmission position of the line of sight on the lens are provided in the lens periphery. It is also possible to obtain and apply the shift on the side by ray tracing.

  Further, in a region other than the main gazing line 14, the sight line 2 with respect to the surfaces 19A and 19B of the lens 10 is inclined from the vertical direction, and the prism effect needs to be considered. However, the relationship of the above equations (11) and (12) is approximately established.

  Similarly, as described above, in order to cancel the toric surface element applied to the object side (outer surface) 19A, it is preferable to operate the surface refractive power of the eyeball side (inner surface side) 19B according to the condition (3a). . However, in the case of a thin lens having a sufficiently small lens thickness, the toric surface element can be almost canceled by the condition (3). Therefore, in the following, the present invention will be further described by taking a thin lens having a sufficiently small lens thickness as an example.

  The progressive-power lens 10a of Example 1 is a progressive zone length of 14 mm as a spectacle specification to a progressive-power lens “Seiko P-1 Synergy AS” (refractive index of 1.67) manufactured by Seiko Epson, which is an internal progressive-power lens. The prescription power (distance power, Sph) was 0.00 (D) and the addition power (Add) was 2.00 (D). The lens 10a has a diameter of 65 mm and does not include astigmatism power.

In the progressive-power lens 10a of the first embodiment, the outer surface 19A is further constituted by a toric surface (toroidal surface) in which the horizontal surface power OHP is larger than the vertical surface power OVP, and the inner surface 19B is formed on the outer surface. The inner surface progressive surface includes an element of a toric surface that cancels the shift of the surface refractive power by the surface. In the progressive-power lens 10a, the outer surface 19A has a horizontal surface power OHP and a vertical surface power OVP that are constant, and a horizontal surface power OHP and a vertical surface power OVP. The toric surface satisfies the following conditions.
OHP-OVP = 3 (D) (13)
That is, the outer surface 19A of the progressive-power lens 10a is formed of a toric surface having a constant horizontal curvature Ch and a vertical curvature Cv, and a horizontal curvature Ch larger than the vertical curvature Cv.

  Further, in the progressive-power lens 10a, the inner surface 19B includes a toric surface element that cancels the shift of the surface power due to the toric surface of the outer surface 19A. That is, since the outer surface 19A includes a region along the main gaze line 14 and the surface refractive power OHP in the horizontal direction is larger than the surface refractive power OVP in the vertical direction in the entire region, the inner surface 19B is also in the main gaze line 14. And a toric surface element in which the horizontal surface power IHP is larger than the vertical surface power IVP in the entire region.

Therefore, in the progressive-power lens 10a of Example 1, the horizontal surface power OMHP of the outer surface 19A in the region along the main line of sight 14 is constant at 9.0 (D) , and the main line of sight 14 is aligned. The surface refractive power OMVP in the vertical direction of the outer surface 19A of the region is constant at 6.0 (D). The horizontal surface refractive power IMHP of the region along the main line of sight 14 of the inner surface 19B is 6.0 (D) for the distance portion 11 and 2.0 (D), and the main power of the inner surface 19B is 2.0 (D). The surface refractive power IMVP in the vertical direction of the region along the line of sight 14 is 3.0 (D) for the distance portion 11 and 2.0 (D) for the addition. For this reason, the progressive addition lens 10a of Example 1 has all the conditions (1) to (10).

  That is, the horizontal surface power OMHP (y) in the region along the main gaze line 14 of the outer surface 19A is larger than the surface power OMVP (y) in the vertical direction (condition (1)). Further, the horizontal surface refractive power IMHP (y) in the region along the main gazing line 14 of the inner surface 19B is larger than the vertical surface refractive power IMVP (y) (condition (2)). The difference between the horizontal surface power OMHP (y) and the vertical surface power OMVP (y) in the region along the main gaze line 14 on the outer surface 19A is along the main gaze line 14 on the inner surface 19B. It is equal to the difference between the surface refractive power IMHP (y) in the horizontal direction of the region and the surface refractive power IMVP (y) in the vertical direction (condition (3)). Further, the difference is constant, and the constant C0 in this example is 3 (D) (condition (4), conditions (5) and (5 ′)).

  Further, in the progressive addition lens 10a of the first embodiment, the horizontal surface refractive power of the entire area of the outer surface 19A and the inner surface 19B is shifted in the intensity direction, not limited to the region along the main line of sight 14. Further, the outer surface 19A of the progressive-power lens 10a of Example 1 is a toric surface having a constant surface power OHP in the horizontal direction and a surface power OVP in the vertical direction. Therefore, the conditions (6) to (10) are satisfied. The constant C1 is 9 (D), and the constant C2 is 6 (D).

2.2 Comparative Example 1
In order to compare with the progressive-power lens 10a of Example 1, as Comparative Example 1, a progressive-power lens 10b having the same spectacle specification as described above and a spherical outer surface 19A was designed.

  FIG. 12A shows the horizontal surface power OMHP (y) along the main line of sight 14 of the outer surface (object side surface) 19A of the progressive addition lens 10b of Comparative Example 1 and the vertical surface power. OMVP (y) is shown in units of diopters (D). FIG. 12B shows a horizontal surface power (surface power) IMHP (y) along the main gaze line 14 of the inner surface (eyeball side) 19B of the progressive-power lens 10b, and a vertical surface. The refractive power (surface refractive power) IMVP (y) is shown in units of diopters (D).

  In the progressive-power lens 10b of Comparative Example 1, since the outer surface 19A is a spherical surface, the horizontal surface power OMHP and the vertical surface power OMVP are the same, 6.0 (D). Further, the values of the horizontal surface power IMHP and the vertical surface power IMVP in the region along the main gazing line 14 of the inner surface 19B are the same, and the distance portion 11 is 3.0 (D) and the addition power is 2.0 (D).

  Note that the changes in the surface refractive power shown in FIGS. 11 and 12 are simply shown for understanding the basic configuration. In actual design, intended aspherical correction for correcting aberrations in lens peripheral vision is added to this, and there is a slight variation in refractive power in the vertical and horizontal directions above the distance portion and near portion. Will arise.

2.3 Comparison In the progressive addition lens 10a of the first embodiment, as shown in FIG. 11A, the surface refractive power OMVP in the vertical direction of the outer surface 19A is the same as that of the progressive addition lens 10b of the first comparison example. The horizontal surface power O MHP is 9.0 (D) from the distance portion 11 to the near portion 12 while 6.0 (D) from the portion 11 to the near portion 12. Accordingly, shifts in the direction of the horizontal surface power O MHP of the outer surface 19A is increased by 3.0 (D). On the other hand, as shown in FIG. 11B, the inner surface 19B also has a direction in which the horizontal surface power IMHP is increased by 3.0 (D) with respect to the vertical surface power IMVP, similarly to the outer surface 19A. Has shifted to. Therefore, as a result, the outer surface 19A is a toric surface, but the shift of the surface refractive power of the outer surface 19A is canceled by the shift of the surface refractive power of the inner surface 19B, and is not different from the progressive power lens 10b of Comparative Example 1. The frequency is secured.

FIG. 13A shows the surface astigmatism distribution of the outer surface 19A of the progressive addition lens 10a of Example 1, and FIG. 13B shows the surface astigmatism of the outer surface 19A of the progressive addition lens 10b of Comparative Example 1. Distribution is shown. FIG. 14A shows an equivalent spherical surface refractive power distribution of the outer surface 19A of the progressive addition lens 10a of Example 1, and FIG. 14B shows an equivalent of the outer surface 19A of the progressive addition lens 10b of Comparative Example 1. The spherical surface refractive power distribution is shown. The equivalent spherical surface refractive power ESP is obtained by the following expression (14).
ESP = (OHP + OVP) / 2 (14)

  The vertical and horizontal straight lines in the figure indicate reference lines (vertical reference line y and horizontal reference line x) passing through the geometric center of the circular lens, and the frame to the spectacle frame with the geometric center as the fitting point as the fitting point. The shape image at the time of insertion is also shown. The same applies to the following drawings.

As shown in FIG. 13 (a), the outer surface 19A of the progressive-power lens 10a of Example 1 includes uniform 3.0 (D) surface astigmatism, but does not show an equivalence line because it is uniform. Further, as shown in FIG. 14 (a), the equivalent spherical surface refractive power of the outer surface 19A is uniform 7.5 (D), and since it is uniform, no equivalence line appears. On the other hand, as shown in FIG. 13B, the outer surface 19A of the progressive addition lens 10b of Comparative Example 1 has a surface astigmatism of 0.0 (D), and as shown in FIG. The equivalent spherical surface power of 19A is uniformly 6.0 (D).

15A shows the surface astigmatism distribution of the inner surface 19B of the progressive addition lens 10a of Example 1, and FIG. 15B shows the surface astigmatism of the inner surface 19B of the progressive addition lens 10b of Comparative Example 1. Distribution is shown. FIG. 16A shows an equivalent spherical surface refractive power distribution of the inner surface 19B of the progressive addition lens 10a of Example 1, and FIG. 16B shows an equivalent of the inner surface 19B of the progressive addition lens 10b of Comparative Example 1. The spherical surface refractive power distribution is shown.

  The surface astigmatism of the progressive-power lens 10a of Example 1 shown in FIG. 15A is basically 3.0 (D) astigmatism having a strong principal meridian in the horizontal direction. In addition to the surface astigmatism of the progressive addition lens 10b of Comparative Example 1 shown in FIG. However, since aspherical correction for adjusting the aberration is added, it is understood that the composition is not simple.

Spherical equivalent surface power shown in FIG. 16 (a) essentially +1.5 (D) is a spherical equivalent surface power distribution of the progressive addition lens 10a of the first embodiment shown in is shown in FIG. 16 (b) It is uniformly added to the equivalent spherical surface refractive power distribution of the progressive addition lens 10b of Comparative Example 1. However, it can be seen that this is not a simple composition due to the effect of aspherical correction.

FIG. 17A shows an astigmatism distribution observed through each position on the progressive-power lens 10a of Example 1, and FIG. 17B shows the progressive-power lens of Comparative Example 1. The astigmatism distribution when observed through each position on the lens 10b is shown. FIG. 18A shows the equivalent spherical power distribution observed through each position on the lens of the progressive addition lens 10a of Example 1, and FIG. 18B shows the progressive refraction of Comparative Example 1. The equivalent spherical power distribution when observing through each position on the lens of the force lens 10b is shown.

The astigmatism distribution of the progressive addition lens 10a of Example 1 shown in FIG. 17A is almost the same as the astigmatism distribution of the progressive addition lens 10b of Comparative Example 1 shown in FIG. is there. Also, the equivalent spherical power distribution of the progressive addition lens 10a of Example 1 shown in FIG. 18A is almost the same as the equivalent spherical power distribution of the progressive addition lens 10b of Comparative Example 1 shown in FIG. It is equivalent. Therefore, as the progressive addition lens 10a of the first embodiment, by effectively using the aspheric correction, the progressive power lens 10b of the comparative example 1 has almost the same performance in the astigmatism distribution and the equivalent spherical power distribution. It turns out that a refractive power lens is obtained.

FIG. 19 shows an index IDd related to vibration obtained by the above-described method for evaluating vibration. FIG. 20 shows index IDs relating to the deformation amount obtained by the above-described fluctuation evaluation method. The viewing angle pitch of the observation target grid 50 is 10 degrees, the head swing is set to the left-right direction, and the swing angle is set to 10 degrees to the left and right. In FIG. 20, the index IDs relating to the deformation amount represents the deformation amount as a ratio (%).

  Regarding the index IDd relating to vibration, “horizontal L” which is the sum of vibrations of all the horizontal grid lines 53 and 54 including the central grid line 53 and similarly the sum of vibrations of all the vertical grid lines 51 and 52 “ Vertical L ”and“ total L ”indicating the sum or average of vibrations of all the lattice lines obtained by adding both of them are shown in the progressive power lens 10a of Example 1 and the progressive power lens 10b of Comparative Example 1. It is obtained at several points along the main line of sight (main meridian). The fitting points Pe of the respective lenses 10a and 10b are in a horizontal front view with a viewing angle of 0 degrees, that is, in the first eye position. The distance portion 11 is 20 degrees upward from the fitting point Pe, and the intermediate portion 13 is downward from the fitting point Pe to about −28 degrees, and the lower portion corresponds to the near portion 12.

  The index IDs relating to the deformation amount is also “horizontal L” which is the sum of the fluctuation areas of all the horizontal grid lines 53 and 54 including the central grid line 53 and the sum of the fluctuation areas of all the vertical grid lines 51 and 52. “Vertical L” and “total L” indicating the total or average of the fluctuation areas of all the lattice lines obtained by adding both of them are referred to as the progressive addition lens 10a of Example 1 and the progressive addition lens of Comparative Example 1. It is obtained at several points along the main line of sight (main meridian) of 10b.

  As shown in FIGS. 19 and 20, the progressive-power lens 10a of Example 1 is smaller than the progressive-power lens 10b of Comparative Example 1 in both the index IDd related to vibration and the index IDs related to deformation. . The improvement effect of the shake is clearly shown in all L of the indices IDd and IDs, and it is shown that the shake is reduced in all the areas in the middle, far and near on the main gazing line 14. In particular, in the area above the distance portion 11 and from the intermediate portion 13 to the near portion 12, the effect of improving the shake is great. Further, when comparing the vertical L and the horizontal L, it can be seen that the improvement effect is greater in the vertical L for any of the indices IDd and IDs.

As described above, the progressive addition lens 10a of Example 1 in which the elements of the toric surface are introduced into the outer surface 19A and the inner surface 19B, the astigmatism distribution and the equivalent spherical power distribution, which are general performances as a spectacle lens, are toric. It has the same performance as that of the progressive addition lens 10b of Comparative Example 1 that is a spherical surface that does not include surface elements (as a spectacle lens that does not target astigmatism correction). Furthermore, it was found that the progressive-power lens 10a of Example 1 can reduce the fluctuation of the image when the line of sight 2 (eyeball 3) moves due to vestibulo-oculomotor reflection compared to the progressive-power lens 10b of Comparative Example 1. . This is because the toric surface element is inserted into the inner and outer surfaces, and particularly when the toric surface element is introduced into the inner and outer surfaces of the region along the main gazing line 14, the line of sight 2 is moved by the vestibulo-oculomotor reflex. It is considered that one of the factors is that the change of the angle at which the line of sight 2 enters and exits the spectacle lens 10a can be suppressed, and the fluctuation of various aberrations when the line of sight 2 moves due to the vestibulo-oculomotor reflection.

  Therefore, the progressive addition lens 10a according to the first exemplary embodiment is a spectacle lens suitable for a user or application that is difficult to adapt to image fluctuation. In this example, the entire outer surface 19A is a toric surface, but as a human visual characteristic when using the progressive addition lens 10, the frequency of use on the main gazing line 14 is extremely large, and the image is swayed. This is felt when the visual work is performed using the vicinity of the main gazing line 14. Therefore, if the horizontal surface refractive power OHP in the outer surface 19A is shifted to the intensity direction at least about 10 mm in the horizontal direction around the main gazing line 14, the effect of reducing the fluctuation of the image can be sufficiently obtained.

3. Embodiment 2
3.1 Example 2
FIG. 21A shows the horizontal surface power (surface power) OMHP (y) along the main line of sight 14 of the outer surface (object side surface) 19A of the progressive-power lens 10c of Example 2 and the vertical direction. The surface refractive power (surface refractive power) OMVP (y) in the direction is shown in units of diopters (D). FIG. 21B shows the horizontal surface power (surface power) IMHP (y) along the main line of sight 14 of the inner surface (eyeball side) 19B of the progressive-power lens 10c, and the surface in the vertical direction. The refractive power (surface refractive power) IMVP (y) is shown in units of diopters (D).

  The progressive-power lens 10c of Example 2 is a progressive-length lens of 14 mm as a spectacle specification to a progressive-power lens “Seiko P-1 Synergy AS” (refractive index of 1.67) manufactured by Seiko Epson, which is an internal progressive-power lens. The prescription power (distance power, Sph) is −3.00 (D) and the addition power (Add) is 2.00 (D). The diameter of the lens 10c is 65 mm and does not include the astigmatism power.

  Similarly to the progressive-power lens 10a of Example 1, the progressive-power lens 10c of Example 2 also has a toric surface (toroidal surface) on the outer surface 19A in which the horizontal surface power OHP is larger than the vertical surface power OVP. The inner surface 19B is formed of an inner surface progressive surface including a toric surface element that cancels the shift of the surface refractive power by the outer toric surface. Therefore, the inner surface 19B also includes a region along the main gazing line 14, and includes a toric surface element in which the horizontal surface power IHP is larger than the vertical surface power IVP in the entire region.

  Specifically, in the progressive addition lens 10c of Example 2, the horizontal surface power OMHP of the outer surface 19A in the region along the main line of sight 14 is constant at 5.5 (D), and the main line of sight 14 The surface refractive power OMVP in the vertical direction of the outer surface 19A in the region along the line is constant at 2.5 (D). Further, the horizontal surface refractive power IMHP of the region along the main line of sight 14 of the inner surface 19B is 8.5 (D) for the distance portion 11 and the addition power 2.0 (D). The surface refractive power IMVP in the vertical direction of the region along the line of sight 14 is 5.5 (D) for the distance portion 11 and the addition power is 2.0 (D). For this reason, the progressive-power lens 10c of Example 2 has all the conditions (1) to (10) as in the progressive-power lens 10a of Example 1. The constant C0 is 3 (D), the constant C1 is 5.5 (D), and the constant C2 is 2.5 (D).

3.2 Comparative Example 2
In order to compare with the progressive-power lens 10c of Example 2, as Comparative Example 2, a progressive-power lens 10d having the same spectacle specification as described above and a spherical outer surface 19A was designed.

  FIG. 22A shows the horizontal surface power OMHP (y) along the main line of sight 14 of the outer surface (object side surface) 19A of the progressive addition lens 10d of Comparative Example 2 and the vertical surface power. OMVP (y) is shown in units of diopters (D). FIG. 22B shows a horizontal surface power (surface power) IMHP (y) along the main line of sight 14 of the inner surface (eyeball side) 19B of the progressive-power lens 10d, and a surface in the vertical direction. The refractive power (surface refractive power) IMVP (y) is shown in units of diopters (D).

  In the progressive-power lens 10d of Comparative Example 2, since the outer surface 19A is a spherical surface, the horizontal surface power OMHP and the vertical surface power OMVP are the same, 2.5 (D). Further, the values of the horizontal surface power IMHP and the vertical surface power IMVP in the region along the main line of sight 14 of the inner surface 19B are the same, and the distance portion 11 is 5.5 (D) and the addition power is 2.0 (D).

  Note that the changes in the surface refractive power shown in FIGS. 21 and 22 are simply shown for understanding the basic configuration. In actual design, intended aspherical correction for correcting aberrations in lens peripheral vision is added to this, and there is a slight variation in refractive power in the vertical and horizontal directions above the distance portion and near portion. Will arise.

3.3 Comparison Also in the progressive addition lens 10c of Example 2, as shown in FIG. 21A, the surface refractive power OMVP in the vertical direction of the outer surface 19A is the same as that of the progressive addition lens 10d of Comparative Example 2. to likewise from the distance portion 11 of 2.5 to the near portion 12 (D), consists of a horizontal surface power O MHP is the distance portion 11 and the near portion 12 to 5.5 (D) ing. Accordingly, shifts in the direction of the horizontal surface power O MHP of the outer surface 19A is increased by 3.0 (D). On the other hand, as shown in FIG. 21B, the inner surface 19B also has a direction in which the horizontal surface power IMHP is increased by 3.0 (D) with respect to the vertical surface power IMVP, as with the outer surface 19A. Has shifted to. Therefore, as a result, the outer surface 19A is a toric surface, but the shift of the surface refractive power of the outer surface 19A is canceled by the shift of the surface refractive power of the inner surface 19B, and is not different from the progressive power lens 10d of Comparative Example 2. The frequency is secured.

FIG. 23A shows the surface astigmatism distribution of the outer surface 19A of the progressive addition lens 10c of Example 2, and FIG. 23B shows the surface astigmatism of the outer surface 19A of the progressive addition lens 10d of Comparative Example 2. Distribution is shown. FIG. 24A shows an equivalent spherical surface refractive power distribution of the outer surface 19A of the progressive addition lens 10c of Example 2, and FIG. 24B shows an equivalent of the outer surface 19A of the progressive addition lens 10d of Comparative Example 2. The spherical surface refractive power distribution is shown.

Similar to the first embodiment, the outer surface 19A of the progressive-power lens 10c of the second embodiment includes a uniform 3.0 (D) surface astigmatism, but does not show an equivalence line because it is uniform. Further, the equivalent spherical surface refractive power of the outer surface 19A is uniformly 4.0 (D), and since it is uniform, no equivalence line appears. On the other hand, the outer surface 19A of the progressive-power lens 10d of Comparative Example 2 has a surface astigmatism of 0.0 (D), and the equivalent spherical surface power of the outer surface 19A is uniformly 2.5 (D).

FIG. 25A shows the surface astigmatism distribution of the inner surface 19B of the progressive addition lens 10c of Example 2, and FIG. 25B shows the surface astigmatism of the inner surface 19B of the progressive addition lens 10d of Comparative Example 2. Distribution is shown. FIG. 26A shows the equivalent spherical surface refractive power distribution of the inner surface 19B of the progressive addition lens 10c of Example 2, and FIG. 26B shows the equivalent inner surface 19B of the progressive addition lens 10d of Comparative Example 2. The spherical surface refractive power distribution is shown.

Similar to the first embodiment, the surface astigmatism of the progressive-power lens 10c of the second embodiment is basically 3.0 (D) with the main principal meridian in the horizontal direction. In addition to the surface astigmatism of the progressive-power lens 10d. However, since aspherical correction for adjusting aberration is added, it is not a simple composition. Further, spherical equivalent surface power of the progressive addition lens 10d of the spherical equivalent surface power is Comparative Example 2 essentially +1.5 (D) is a spherical equivalent surface power distribution of the progressive addition lens 10c of Example 2 A uniform addition to the distribution. However, due to the effect of aspherical correction, this is not a simple composition.

FIG. 27A shows an astigmatism distribution when observed through each position on the progressive-power lens 10c of Example 2, and FIG. 27B shows the progressive-power lens of Comparative Example 2. Astigmatism distribution when observed through each position on the lens of 10d is shown. FIG. 28A shows an equivalent spherical power distribution observed through each position on the lens of the progressive addition lens 10c of Example 2, and FIG. 28B shows the progressive refraction of Comparative Example 2. An equivalent spherical power distribution when viewed through each position on the lens of the force lens 10d is shown.

The astigmatism distribution of the progressive addition lens 10c of Example 2 shown in FIG. 27A is almost equal to the astigmatism distribution of the progressive addition lens 10d of Comparative Example 2 shown in FIG. is there. Further, the equivalent spherical power distribution of the progressive addition lens 10c of Example 2 shown in FIG. 28A is almost the same as the equivalent spherical power distribution of the progressive addition lens 10d of Comparative Example 2 shown in FIG. It is equivalent. Therefore, by effectively using the aspherical correction as the progressive addition lens 10c of the second embodiment, the progressive power lens 10c of the comparative example 2 has almost the same performance in the astigmatism distribution and the equivalent spherical power distribution. It turns out that a refractive power lens is obtained.

  FIG. 29 shows an index IDd related to vibration obtained by the above-described method for evaluating vibration. Further, FIG. 30 shows index IDs relating to the deformation amount obtained by the above-described fluctuation evaluation method. The viewing angle pitch of the observation target grid 50 is 10 degrees, the head swing is set to the left-right direction, and the swing angle is set to 10 degrees to the left and right. As in the first embodiment, the index IDd related to vibration indicates “horizontal L”, “vertical L”, and “all L”, and the index IDs related to deformation amounts also indicate “horizontal L” and “vertical”. L ”and“ all L ”.

  It can be seen that the image fluctuations obtained by the progressive addition lenses 10c and 10d of the second embodiment are relatively smaller than the image fluctuations obtained by the progressive addition lenses 10a and 10b of the first embodiment. For this reason, the difference between the indices IDd and IDs of the progressive power lens 10c and the indices IDd and IDs of the progressive power lens 10d is small. However, the indices IDd and IDs of the progressive-power lens 10c of Example 2 are smaller than the indices IDd and IDs of the progressive-power lens 10d of Comparative Example 2 over all regions near and far from the main line of sight 14. It can be seen that the vibration is improved by the progressive addition lens 10c of the second embodiment. In particular, the fluctuation is reduced in a wide range from the distance portion 11 to the intermediate portion 13.

  In the above description, the square lattice 50 of the square lattice is used as the pattern of the observation index for evaluation. However, the accuracy and density of evaluation in each direction can be improved by changing the lattice pitch in the horizontal direction and the vertical direction. It is also possible to change the accuracy and density of evaluation by changing the number of grids.

  FIG. 31 shows an outline of a process for designing and manufacturing a progressive-power lens for spectacles. In step 101, a toric surface having a horizontal surface power OHP greater than a vertical surface power OVP is set on the outer surface 19A. Next, in step 102, the inner surface 19B has a toric surface that cancels the shift of the surface power of the toric surface of the outer surface 19A, that is, the surface power IHP in the horizontal direction is larger than the surface power IVP in the vertical direction. Set a progressive surface that meets spectacle specifications, including surface elements. Further, in step 103, the progressive-power lens 10 for spectacles designed in the above step is manufactured.

  In the progressive-power lens 10 for spectacles, the outer surface 19A is a toric surface in which the horizontal surface power OHP is larger than the vertical surface power OVP, and the inner surface 19B is a toric surface equivalent to the outer surface 19A. Contains the elements. Therefore, the progressive-power lens 10 is a lens in which the entire lens is curved in a toroidal shape along the face, and the horizontal direction of the lens outer surface is deeper than the conventional one. Therefore, the progressive-power lens 10 is suitable for a spectacle design in which the lens wraps around the temple side in accordance with the curve of the face, which is called a wraparound type, which has been attracting attention in recent years.

  In the above description, the present invention has been described by taking the spectacle lens 10 in which the horizontal surface power OHP and the vertical surface power OVP of the outer surface 19A are constant as an example. However, the horizontal surface power OHP and the vertical surface power OVP are constant. The surface refractive power OVP includes the horizontal surface refractive power OMHP and the vertical surface refractive power OMVP along the main gazing line 14 or the vertical reference line, and the vertical direction (y direction) and / or the horizontal direction (x direction). It may change along. The surface power OHP (x, y) in the horizontal direction at a certain coordinate of the outer surface 19A is larger than the surface power OVP (x, y) in the vertical direction, and the shift of the surface power of the outer surface 19A to the inner surface 19B is cancelled. If the toric surface element is included, as described above, the change in the angle when the line of sight 2 passes through the spectacle lens 10 can be suppressed with respect to the movement of the line of sight 2, thereby suppressing variations in various aberrations. It is easy to improve the shaking. In particular, even when the horizontal surface power OMHP (y) and the vertical surface power OMVP (y) along the main gaze line 14 or the vertical reference line change, the horizontal surface at a certain coordinate If the refractive power OMHP (y) is larger than the vertical surface refractive power OMVP (y) and the inner surface 19B includes a toric surface element that cancels the shift of the surface refractive power of the outer surface 19A, the image The effect of suppressing the shaking is great.

  In the above description, an example of the progressive-power lens of the inner surface progressive type is described. However, it may be a progressive-power lens of the outer surface progressive type, and further includes an element of the progressive surface (intermediate portion) on the inner and outer surfaces. It may be a progressive power lens.

The above explanation is for the case where there is no astigmatism prescription in the distance prescription, but when there is an astigmatism prescription, astigmatism is synthesized by synthesizing the toric surface ( toroidal surface) component for astigmatism correction on the inner surface side. A prescription can be included. Further, when the lens thickness is large, a spectacle lens with higher accuracy can be provided by correcting the inner surface side in consideration of the shape factor.

DESCRIPTION OF SYMBOLS 1 Glasses, 10, 10L, 10R Glasses lens 11 Distance part, 12 Near part, 13 Middle part (progressive part)
19A Object side surface, 19B Eyeball side surface 20 Frame

Claims (12)

A progressive-power lens for spectacles including a distance portion and a near portion having different powers,
Horizontal surface refractive power OMHP (y) of the object side surface along the vertical reference line passing through the main gaze line or fitting point, vertical surface refractive power OMVP (y) of the object side surface, and the eyeball side Progressive power lens in which the absolute value IMHP (y) of the surface refractive power in the horizontal direction and the absolute value IMVP (y) of the surface refractive power in the vertical direction of the surface on the eyeball side satisfy the following conditions.
OMHP (y)> OMVP (y)
IMHP (y)> IMVP (y)
OMHP (y) -OMVP (y) = IMHP (y) -IMVP (y)
However, astigmatism prescription is not included, and y is a coordinate along the main gaze line or the vertical reference line. The progressive-power lens according to claim 1, further satisfying the following condition.
OMHP (y) -OMVP (y) = IMHP (y) -IMVP (y) = C0
However, C0 is a constant.   The progressive-power lens according to claim 2, wherein the eyeball side surface is a progressive surface. 4. The horizontal refractive power OHP (y) in the horizontal direction of the object-side surface within a range of ± 10 mm across the main gaze line or the vertical reference line, and the vertical of the object-side surface according to claim 2 or 3 Surface refractive power OVP (y) in the direction, absolute value IHP (y) of the horizontal surface power of the eyeball side surface, and absolute value IVP (y) of the vertical surface power of the eyeball side surface. ) And progressive-power lenses satisfying the following conditions.
OHP (x, y)> OVP (x, y)
IHP (x, y)> IVP (x, y)
OHP (x, y) -OVP (x, y) = IHP (x, y) -IVP (x, y) = C0
Where x is the coordinate of a horizontal reference line passing through the fitting point. 5. The progressive-power lens according to claim 4, further satisfying the following condition within a range of ± 10 mm across the main gaze line or the vertical reference line.
OHP (x, y) = C1
OVP (x, y) = C2
However, C1 and C2 are constants. A progressive-power lens for spectacles including a distance portion and a near portion having different powers,
The object-side surface and the eyeball-side surface are elements of a toric surface that have a larger lateral curvature than a longitudinal curvature, respectively, at least along a vertical reference line passing through the main gaze line or fitting point. A progressive power lens including a toric surface element that mutually cancels a shift in surface power due to the toric surface element. In claim 6,
Horizontal surface refractive power OMHP (y) of the object side surface along the vertical reference line passing through the main gaze line or fitting point, vertical surface refractive power OMVP (y) of the object side surface, and the eyeball side Progressive power lens in which the absolute value IMHP (y) of the surface refractive power in the horizontal direction and the absolute value IMVP (y) of the surface refractive power in the vertical direction of the surface on the eyeball side satisfy the following conditions.
OMHP (y)> OMVP (y)
IMHP (y)> IMVP (y)
OMHP (y) -OMVP (y) = IMHP (y) -IMVP (y)
However, astigmatism prescription is not included, and y is a coordinate along the main gaze line or the vertical reference line. In claim 6,
Horizontal surface refractive power OMHP (y) of the object side surface along the vertical reference line passing through the main gaze line or fitting point, vertical surface refractive power OMVP (y) of the object side surface, and the eyeball side Progressive power lens in which the absolute value IMHP (y) of the surface refractive power in the horizontal direction and the absolute value IMVP (y) of the surface refractive power in the vertical direction of the surface on the eyeball side satisfy the following conditions.
OMHP (y)> OMVP (y)
IMHP (y)> IMVP (y)
IMHP (y) -IMVP (y) =
OMHP (y) / (1-t / n * OMHP (y))-OMVP (y) /
(1-t / n * OMVP (y))
However, astigmatism prescription is not included, y is a coordinate along the main gazing line or the vertical reference line, t is the thickness of the progressive power lens, and n is the refractive index of the base material of the progressive power lens.   9. The progressive power lens according to claim 5, wherein the object side surface is a toric surface. A progressive-power lens according to any one of claims 1 to 9,
Eyeglasses having an eyeglass frame to which the progressive addition lens is attached. A method for designing a multifocal lens for spectacles including a distance portion and a near portion having different powers,
Horizontal surface refractive power OMHP (y) of the object side surface along the vertical reference line passing through the main gaze line or fitting point, vertical surface refractive power OMVP (y) of the object side surface, and the eyeball side And selecting the absolute value IMHP (y) of the surface refractive power in the horizontal direction of the surface of the lens and the absolute value IMVP (y) of the vertical surface refractive power of the surface on the eyeball side so as to satisfy the following relationship: , How to design.
OMHP (y)> OMVP (y)
IMHP (y)> IMVP (y)
OMHP (y) -OMVP (y) = IMHP (y) -IMVP (y)
However, y is a coordinate along the main gaze line or the vertical reference line. The design method according to claim 11, wherein the selecting includes selecting to satisfy the following condition.
OMHP (y) -OMVP (y) = IMHP (y) -IMVP (y) = C0
However, C0 is a constant.

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