JP2011070234A - Progressive-power lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inner face progressive-power lens that solves defects such as thinness of a lens or appearances in the inner face progressive-power lens with a progressive refraction surface on a refractive surface of a side of augen. <P>SOLUTION: A refractive surface 11 of a side of augen of a distant portion is concave and at least part of a refractive surface 3 of the side of the augen of a near portion is a convex region 31 where one or both of principal meridians of the surface are convex. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a progressive-power lens used mainly for spectacles for correcting presbyopia.

  The progressive power lens is a lens having two field parts having different refractive powers and a field part in which the refractive power changes progressively between them. Furthermore, a field of different refractive power can be obtained with one lens. For this reason, it is often used as a spectacle lens having a vision correction function such as presbyopia.

  FIG. 3 shows a general structure of a progressive power lens. 3A is a front view, and FIG. 3B is a longitudinal sectional view. The progressive power lens 100 is provided with a distance portion 2 which is a field portion for viewing a relatively far distance, and a field of view having a refractive power different from that of the distance portion 2 for viewing a relatively near distance. The portion is provided below the distance portion 2 as the near portion 3. The distance portion 2 and the near portion 3 are smoothly smoothed by an intermediate portion (progressive portion) 4 which is a visual field portion having a refractive power that continuously changes in order to see an object at an intermediate distance between the distance and the near. Have been contacted.

  In a single-plate lens used for spectacles, all the performance required for the spectacle lens by the two surfaces of the eyeball-side refractive surface 11 and the object-side refractive surface 12, for example, the apex that matches the power of the user It is necessary to provide a refractive power, a cylindrical refractive power for correcting astigmatism, an addition refractive power for correcting presbyopia, and a prism refractive power for correcting oblique position. For this reason, in the conventional progressive-power lens, the progressive refractive surface that gives the refractive power that continuously changes to form the distance portion 2, the near portion 3, and the intermediate portion 4 is the refractive surface 12 on the object side. The eyeball side refractive surface 11 is used as a refractive surface for correcting astigmatism.

  In such an outer surface progressive addition lens having a progressive refractive surface on the object-side refractive surface 12, the distortion of the image increases. For this reason, a person who uses a progressive power lens for the first time or a person who changes from a progressive power lens of another design may feel uncomfortable.

  In order to suppress the occurrence of distortion due to such a change in image magnification of the outer surface progressive-power lens, an inner surface in which a progressive refraction surface is arranged on the refraction surface 11 on the eyeball side as shown in Patent Document 1 recently. A so-called progressive power lens has also been commercialized. In the inner surface progressive-power lens 100, as shown in FIG. 3B, the object-side refractive surface 12 is a spherical surface or a rotationally symmetric aspherical surface. The eyeball-side refracting surface 11 is provided with a progressive refracting surface having a distance portion 2, a near portion 3, and an intermediate portion 4, and the toric surface is further corrected on the progressive refracting surface and further correction for correcting off-axis aberrations of the lens. A complex curved surface combining aspherical elements is used. Further, Patent Document 2 describes a technique for thinning the inner surface progressive addition lens 100.

International Publication No. 97/19382 Pamphlet JP 2000-227579 A

  However, in order to make the inner surface progressive addition lens curved so as to obtain the addition power on the inner surface side, the surface refractive power of the distance portion is set to a value larger by the addition power than the surface power of the near portion. There must be. Furthermore, it is necessary for the inner surface progressive-power lens to secure the distance power required for the distance portion. For example, when the distance portion has a plus prescription, it is necessary to increase the surface refractive power of the object-side refractive surface according to the plus prescription. Therefore, in the inner surface progressive addition lens having a plus prescription in the distance portion, the protrusion of the convex surface of the refractive surface on the object side is larger than that of the outer surface progressive addition lens. As described above, the inner surface progressive addition lens is advantageous in terms of optical performance such as image distortion, but has disadvantages in terms of thinness and appearance of the lens. A thinning technique as shown in Patent Document 2 described above has been proposed, but is insufficient.

  The present invention has been made in view of the above circumstances, and an inner surface progressive addition lens capable of solving defects in terms of thinness and appearance of the lens in an inner surface progressive addition lens having a progressive addition surface on the refractive surface on the eyeball side. The purpose is to provide.

  In order to achieve the above object, the present invention firstly has two refracting surfaces of the object side and the eyeball side, and the eyeball side refracting surface has a refracting power for relatively far viewing. In a progressive-power lens having a power portion, a near power portion having a refractive power for relatively viewing near, and an intermediate portion having a power for continuously viewing an intermediate distance therebetween, The eye-side refracting surface of the distance portion has a concave shape, and at least part of the eye-side refracting surface of the near portion has a convex region where one or both of the principal meridians of the surface are convex. A progressive power lens characterized by the above is provided.

  This inner surface progressive addition lens has a structure in which a convex surface region convex toward the eyeball side is provided in the region of the near portion of the refractive surface on the eyeball side. By providing the convex area in the near portion, the distance portion on the eyeball side can be a concave surface having a small curvature when obtaining a predetermined addition power. Furthermore, the curvature of the refracting surface on the object side for securing the refractive power necessary for the distance portion can be reduced in accordance with the small curvature on the eyeball side. Therefore, by providing the convex area in the near portion, a shallow base curve is obtained. As a result, the appearance can be improved and the thickness can be reduced.

  The present invention secondly provides the progressive power lens according to the first progressive power lens, wherein the maximum surface power of the principal meridian of the convex region does not exceed 2 diopters in absolute value. .

  By providing a convex surface area in the near portion, it is possible to realize a thin inner surface progressive addition lens having a good appearance. On the other hand, as the base curve becomes shallow, the astigmatism increases, resulting in a problem that the optical performance deteriorates. This problem can be overcome by advances in design technology. In the present application, the deterioration of the optical performance can be minimized by further limiting the degree of convexity of the convex surface region.

  Thirdly, in the first or second progressive-power lens according to the present invention, the area ratio occupied by the convex surface region within a radius of 25 mm from the geometric center of the progressive-power lens is 30% or less. A progressive-power lens is provided.

  By limiting the area ratio occupied by the convex region, it is possible to minimize the deterioration of the optical performance due to the shallow base curve.

The concept of the progressive-power lens of this invention is shown, (a) is a front view, (b) is sectional drawing. (A) of this invention, (b) is a figure which shows the refractive power of each surface of the conventional progressive-power lens. The concept of the conventional progressive-power lens is shown, (a) is a front view, (b) is sectional drawing. An example of the double focus lens which provided the small ball in the refractive surface by the side of an eyeball is shown, (a) is a front view, (b) is sectional drawing. FIG. 3 is a surface refractive power distribution diagram of an eyeball side refractive surface of the progressive-power lens of Example 1; FIG. 4 is an astigmatism distribution diagram on the eyeball side refractive surface of the progressive-power lens of Example 1; FIG. 6 is a visual aberration diagram of the progressive-power lens of Example 1. FIG. 3 is a coordinate diagram of a refractive surface on the eyeball side of the progressive-power lens of Example 1. FIG. 5 is a surface refractive power distribution diagram of an eyeball side refractive surface of the progressive-power lens of Example 2. FIG. 6 is an astigmatism distribution diagram on the eyeball side refractive surface of the progressive-power lens of Example 2. FIG. 6 is a visual aberration diagram of the progressive-power lens of Example 2. 6 is a coordinate diagram of an eyeball side refractive surface of a progressive-power lens according to Embodiment 2. FIG. The surface refractive power distribution map of the eyeball side refractive surface of the progressive-power lens of a comparative example. The astigmatism distribution diagram of the eyeball side refractive surface of the progressive-power lens of the comparative example. The visual aberration diagram of the progressive-power lens of a comparative example. The coordinate figure of the eyeball side refractive surface of the progressive-power lens of a comparative example.

  Hereinafter, embodiments of the progressive-power lens according to the present invention will be described, but the present invention is not limited to the following embodiments.

  1A and 1B show the concept of a progressive-power lens according to the present invention, where FIG. 1A is a front view and FIG. 1B is a longitudinal sectional view. The progressive-power lens 1 is a meniscus lens, and has a concave refractive surface provided with a progressive refractive surface 11 on the eyeball side, and the convex object-side refractive surface 12 is, for example, spherical or rotationally symmetric. It is an inner surface progressive addition lens formed in an aspherical surface. The progressive refracting surface provided on the eyeball side refracting surface 11 includes a distance portion 2 having a refractive power for relatively looking at a distance and a near portion having a refractive power for relatively looking at a near distance. 3 and an intermediate portion 4 having a refractive power for continuously viewing these intermediate distances. In addition to the progressive refractive surface, the refractive surface 11 on the eyeball side has, for example, a cylindrical refractive power as a refractive power for correcting astigmatism, a prism refractive power for correcting oblique position, and an aspherical surface for correcting aberration. Is granted.

  The progressive-power lens 1 of the present invention is such an internal progressive-power lens, and the refracting surface of the distance portion 2 has a concave shape on the eyeball side. In other words, the center of the radius of curvature of the refractive surface of the distance portion 2 is present on the eyeball side with respect to the refractive surface. Further, in at least a part of the refracting surface of the near portion 3, one or both of the principal meridians of the surface are convex to the eyeball side, in other words, one of the principal meridians of one surface having the refracting surface of the near portion 3. Or the center of both the curvature radii has the convex surface area | region 31 which exists in the object side rather than the refractive surface. The convex surface region 31 is a region where the average surface refractive power is negative when the sign of the surface refractive power is positive on the object side and the convex shape on the eyeball side is negative.

  As shown in FIG. 1B, the convex surface region 31 is located on the refractive surface 11 on the eyeball side including the distance portion 2 and having a concave shape of the meniscus lens, and the eyeball in the region of the near portion 3. Convex shape to the side. The convex surface region 31 is defined as one or both of the principal meridians of the surface convex toward the eyeball side. In the inner surface progressive addition lens, a refractive surface in which a progressive refractive surface and a toric surface for correcting astigmatism are combined. In the convex surface area of the synthetic refractive surface, one of the principal meridians of the surface is concaved toward the eyeball side by the toric surface, and the other of the principal meridians of the surface is convex toward the eyeball side. Because there is. In order to be convex toward the eyeball side, at least one of the principal meridians of the surface needs to be convex toward the eyeball side. The principal meridian of a surface has a maximum curvature and a minimum curvature at one point on the surface as defined in JIS standard (JIS / T7330: published on October 18, 2000: Japan Industrial Standards Committee). A meridian.

  By providing a convex surface region 31 convex on the eyeball side in the near portion, the distance portion 2 of the refractive surface on the eyeball side 11 can have a concave surface with a small curvature in order to obtain a predetermined addition refractive power. The curvature of the refracting surface 12 on the object side for ensuring the distance refracting power necessary for the distance portion 2 can be reduced according to the small curvature of the distance portion 2 on the eyeball side. By providing the convex region 31 in the near portion 3, the object-side refractive surface 12, called a base curve, can be made shallow, so that an internal progressive-power lens that has a good appearance and can be made thin. 1 can be realized.

The fact that a shallow base curve can be obtained by providing a convex surface area in the near portion will be specifically described. In the inner surface progressive addition lens, the object side (outer surface) surface refractive power (base curve) D1, the eyeball side (inner surface) distance portion surface refractive power D2f, the near portion surface refractive power D2n, and the lens prescription power are configured. The following relationship exists between the distance dioptric power S and the addition power Ad.
S = D1-D2f
Ad = D2f-D2n
Here, the unit expressing these refractive powers is diopter (D), and the respective signs of the surface refractive powers D1, D2f, and D2n are + for the case of convex on the object side (concave on the eyeball side), and on the object side. The case of concave (convex to the eyeball side) is set to −.

In a conventional inner surface progressive-power lens, the near-surface refractive power D2n is D2n ≧ 0 (D)
Met. That is, the entire near portion is concave or part is flat.
For this reason, when the distance power is + and the power is high, the base curve is the sum of the distance power S, the power Add, and the near surface power D2n, as shown by the following formula. In the case of a refractive power lens, the base curve has to be deeper than a lens having a progressive surface on the outer surface (outer surface progressive lens).
D1 = S + D2f = S + Ad + D2n
As a result, there was a problem that the external appearance of the product was projected and the appearance was poor. There is also a problem that the center thickness is also increased.

  On the other hand, when the convex portion is provided in the near portion, the near portion surface refractive power D2n becomes negative, and as a result, the object side (outer surface) surface refractive power (base curve) D1 can be made shallow.

  With reference to FIG. 2, it demonstrates actually with a number. FIG. 2A shows an internal progressive-power lens according to the present invention, and FIG. 2B shows a conventional internal progressive-power lens in which the refractive surface on the eyeball side is entirely concave. Both lenses have the same prescription power of distance use S of 3.50D and addition power Ad of 2.00D. In the conventional inner surface progressive addition lens shown in FIG. 2B, the near portion surface refractive power D2n is set, for example, to +0.50 D (concave surface) close to a plane. Thereby, the distance portion surface refractive power D2f is 2.50D by adding the addition power Ad2.00D, and the object side surface refractive power (base curve) D1 is added to the distance portion surface refractive power D2f and the distance power S3.50D. Is added to 6.00D, resulting in a deep base curve.

  In the inner surface progressive addition lens of the present invention shown in FIG. 2A, the near-surface refractive power D2n of the near-surface convex surface area is concave on the object side, and thus, for example, -1.50D ( Convex to eyeball side). The distance portion surface power D2f is 0.50D by adding the addition power Ad2.00D, and the object side surface power (base curve) D1 is obtained by adding the distance power S3.50D to the distance portion surface power D2f. 4.00D, a shallow base curve.

  As described above, the inner surface progressive addition lens according to the present invention can be provided with a convex surface region in the near portion and the base curve can be made shallow, so that the lens appearance can be improved and the thickness can be reduced. However, when the base curve is made shallower, astigmatism increases, and it is recognized that the optical performance is inferior compared with a conventional inner surface progressive-power lens in which the entire refractive surface on the eyeball side is concave. In addition, if a convex surface area convex to the eyeball side is provided on the refractive surface on the eyeball side constituted by a concave surface, the distance portion becomes concave by the addition, so that the refractive surface on the eyeball side is complicated with unevenness. There arises a problem that the surface shape creation processing and mirror polishing processing become difficult.

  The problem of difficulty in processing has been overcome by recent significant advances in manufacturing technology. Further, the problem of increasing astigmatism has been overcome by the recent development of computers, which has improved the design technology and can appropriately add an aspheric surface to correct astigmatism.

  Further, as a result of examining the degree of convexity of the convex region in order to improve the optical performance, the maximum surface refractive power of the convex main meridian on the eyeball side in the convex region does not exceed 2 diopters in absolute value. It has been found desirable not to exceed 5 diopters. If the degree of convexity in the convex surface area is too large, the optical performance deteriorates, and it may be difficult to correct astigmatism by adding an aspherical surface. Further, the reflection of light at the convex surface area that is convex becomes strong, and the reflected light becomes troublesome. Furthermore, when the degree of convexity increases, the refractive surface of the convex surface area may approach the eyeball and come into contact with the eyelashes.

  Furthermore, it has been found that the area of the convex area also affects the optical performance. Specifically, it is desirable that the area ratio occupied by the convex surface area within the radius 25 mm from the geometric center of the circular lens before processing the target lens is 30% or less, particularly 20% or less, and particularly 15% or less. If the area ratio occupied by the convex surface area is larger than this range, the optical performance may be deteriorated, and it may be difficult to correct astigmatism by adding an aspheric surface, and reflection on the convex surface area may increase, which may be bothersome. There is.

  The internal progressive addition lens of the present invention includes various design types. For example, in the design for each application, both the far vision and the near vision are arranged in a well-balanced manner, and the progressive zone length is set to about 10 to 16 mm so that the eye can be easily rotated during near vision. There is a perspective type. In addition, there are so-called near and near types that emphasize the field of view from the middle region of about 1 m to the hand, especially the so-called near type that emphasizes the field of view at hand. In order to realize a wide field of view, the progressive zone length is designed as long as about 19 to 25 mm. The above-described area ratio of the convex surface area is also applicable to the case where the main part is the near-use part, such as the middle and near type. Also, in the design of distortion and astigmatism distribution, the distance-use and near-use parts are widened, the aberration-concentrated type in which aberrations are concentrated in a narrow progressive part, and the distance-use and near-use parts are narrowed, It can be roughly classified into an aberration dispersion type in which the progressive portion is widened and the aberration in the intermediate portion is diffused. The present invention can accommodate such different types of designs.

  Conventionally, a bifocal lens is known in which small balls are provided on the refractive surface on the eyeball side. FIG. 4 shows an example of a bifocal lens in which small balls are provided on the refractive surface on the eyeball side. 4A is a front view, and FIG. 4B is a longitudinal sectional view. The bifocal lens 200 is divided into a distance portion 210 and a near portion 220. Generally, the distance portion 210 is referred to as a ball and the near portion 220 is referred to as a small ball. The bifocal lens 200 shown in FIG. 4 is formed by adhering a small ball 220 to an eyeball-side refractive surface 230. The object-side refractive surface 240 is a convex surface, and the eyeball-side refractive surface 230 of the table ball 210 is a concave surface. An eyeball side refractive surface 221 of 220 is convex on the eyeball side.

  The bifocal lens 200 in which the small balls 220 are provided on the refractive surface 230 on the eyeball side includes an inner surface progressive addition lens 1 having a convex surface area on the refractive surface on the eyeball side of the present invention, and a lower refractive surface on the concave eyeball side. Since there is a common point in which there is a protruding surface, it is approximate in appearance.

  However, in the double focus lens 200, a boundary line is formed between the refractive surface 230 on the eyeball side of the pedestal 210 and the refractive surface 221 of the small ball. The bifocal lens 200 is a so-called multifocal lens with a boundary, and has a drawback that an image becomes discontinuous at the boundary line. There is also a problem that it is known that the appearance is presbyopia. There is also a so-called seamless type in which the boundary line of the boundary is smoothed and not understood. However, this seamless type has a problem that it becomes blurred along the smoothed width and cannot be used optically. In any case, a bifocal lens having a small ball has an intermediate portion (progressive portion) that is a visual field portion having a refractive power that continuously changes in order to see an object at an intermediate distance between far and near. It is a spectacle lens that is completely different from the progressive power lens.

Example 1
The distance portion refractive power D2f is 1.00D, the near portion refractive power D2n is -1.00D, the addition power Ad is 2.00D, the distance power S is 3.50D, and the refractive power of the object side refractive surface is (Base curve) An inner surface progressive addition lens having D1 of 4.50D and having a convex region convex toward the eyeball side in the near portion of the refractive surface on the eyeball side was designed. The refractive index of the lens material is 1.66, and the following examples and comparative examples all use a lens material having the same refractive index. In this design, a convex surface area is simply provided in the near portion of the conventional inner surface progressive-power lens having a full concave surface, and the increase in astigmatism due to the shallow base curve is not corrected.

  In such a design, if the lens is circular with a diameter of 70 mm, and the line connecting the geometric center of the object side refractive surface and the geometric center of the eyeball side refractive surface is a center line, the geometric center of the object side refractive surface is The bulge h (see FIG. 1B), which is the distance in the center line direction between the refracting surface and the outer edge of the object side refractive surface, is 4.2 mm, and the center thickness t (see FIG. 1B), which is the distance between the center lines, is It became 4.4 mm.

  FIG. 5 shows the surface refractive power distribution of the refractive surface on the eyeball side of the inner surface progressive-power lens for the right eye (the near portion is displaced toward the nose in consideration of convergence) of this design. FIG. 5 shows a circle having a radius of 25 mm from the geometric center of the intersection of the horizontal and vertical lines indicated by the alternate long and short dash line. The area ratio occupied by the convex area inside the circle is 21%.

  FIG. 6 shows the astigmatism distribution on the refractive surface on the eyeball side. Further, FIG. 7 shows actual astigmatism distributions (hereinafter referred to as visual aberration distributions) acting on the eyes when the lens is worn and the objects at the target distances of the distance portion, the intermediate portion, and the near portion are viewed. FIG. 8 shows the coordinate values of the refractive surface on the eyeball side with the geometrical center point of the lens as the origin.

(Example 2)
The distance portion refractive power D2f is 1.00D, the near portion refractive power D2n is -1.00D, the addition power Ad is 2.00D, the distance power S is 3.50D, and the refractive power of the object side refractive surface is (Base curve) An inner surface progressive addition lens having a convex surface area convex on the eyeball side at the near portion of the refractive surface on the eyeball side with a D1 of 4.50D was designed. In this design, an aspheric surface for correcting an increase in astigmatism due to the shallow base curve was added.

  In such a design, assuming that the lens is circular with a diameter of 70 mm, the protrusion h in the center line direction between the geometric center of the object side refractive surface and the outer edge of the object side refractive surface is 4.2 mm, and the center thickness t. Was 4.1 mm. By adding an aspherical surface, the center thickness t was 0.3 mm thinner than that of Example 1.

  FIG. 9 shows the surface refractive power distribution of the refractive surface on the eyeball side of the inner surface progressive addition lens for the right eye of this design. FIG. 9 shows a circle having a radius of 25 mm from the geometric center of the intersection of the horizontal and vertical lines indicated by the alternate long and short dash line. The area ratio occupied by the convex area inside the circle is 17%. FIG. 10 shows the astigmatism distribution of the eyeball side refractive surface, FIG. 11 shows the visual aberration distribution, and FIG. 12 shows the coordinate values of the eyeball side refractive surface with the geometric center point of the lens as the origin.

  FIG. 6 showing the astigmatism distribution on the refractive surface on the eyeball side in Example 1 is compared with FIG. 10 showing the astigmatism distribution on the refractive surface on the eyeball side in Example 2, and in FIG. Since an aspherical surface that corrects an increase in astigmatism due to a shallow base curve is added to the refracting surface, astigmatism is increased in Example 2. However, comparing FIG. 7 showing the visual aberration of Example 1 with FIG. 11 showing the visual aberration of Example 2, it can be seen that Example 2 has a better correction of the overall astigmatism.

(Comparative example)
A conventional inner surface progressive-power lens was designed in which the refractive surface on the eyeball side without any convex surface area in the near portion was all concave. The distance surface power D2f is 3.00D, the near surface power D2n is 1.00D, the addition power Ad is 2.00D, the distance power S is 3.50D, and the refractive power of the object side refractive surface ( Base curve) D1 is 6.50D.

  In such a design, assuming that the lens is circular with a diameter of 70 mm, the protrusion h in the center line direction between the geometric center of the object side refractive surface and the outer edge of the object side refractive surface is 6.2 mm, and the center thickness t. Was 4.4 mm. In the design of this comparative example, the protrusion h of the object-side refracting surface is 2.0 mm larger than those of Examples 1 and 2 of the present invention. The center thickness t is almost the same as when no aspheric surface is added to correct astigmatism as in the first embodiment, but is 0.3 mm thicker than that when an aspheric surface is added as in the second embodiment. became.

  FIG. 13 shows the surface power distribution of the refractive surface on the eyeball side of the inner surface progressive-power lens for the right eye of this design, FIG. 14 shows the astigmatism distribution of the refractive surface on the eyeball side, and FIG. 15 shows the visual aberration distribution. The coordinate values of the refractive surface on the eyeball side with the geometrical center point of the lens as the origin are shown in FIG.

  The prescription powers of Example 1, Example 2, and Comparative Example are the same, the distance power S is 3.50D, and the addition power Ad is 2.00D. FIG. 7 showing the visual aberration of Example 1 is compared with FIG. 11 showing the visual aberration of Example 2, and FIG. 15 showing the visual aberration of the comparative example. In FIG. 7 of Example 1 in which a convex surface region is simply provided and the base curve is shallow, the visual aberration is greatly deteriorated as compared with FIG. 15 of the conventional inner surface progressive addition lens. On the other hand, in FIG. 11 of Example 2 in which an aspherical surface that corrects an increase in astigmatism due to the shallow base curve is added to the refractive surface on the eyeball side, in FIG. It can be seen that the optical performance is significantly improved with the same visual aberration as in FIG.

  The progressive-power lens of the present invention can be used mainly for spectacles for correcting presbyopia.

  1: progressive power lens, 2: distance portion, 3: near portion, 4: intermediate portion, 31: convex surface region, 11: eyeball side refractive surface, 12: object side refractive surface.

Claims (3)

A refracting power having two refractive surfaces on the object side and an eyeball side, the refracting surface on the eyeball side having a refractive power for relatively looking at the far side, and a refractive power for viewing the relatively near side In a progressive-power lens having a near portion having a refractive index and an intermediate portion having a refractive power for continuously seeing an intermediate distance between them,
An eyeball side refracting surface of the distance portion has a concave shape, and at least a part of the eyeball side refracting surface of the near portion has a convex region where one or both of the principal meridians of the surface are convex. A progressive power lens characterized by that. The progressive-power lens according to claim 1,
A progressive power lens, wherein the maximum surface refractive power of the principal meridian of the convex surface area does not exceed 2 diopters in absolute value. The progressive-power lens according to claim 1 or 2,
The progressive-power lens, wherein an area ratio occupied by the convex surface area within a radius of 25 mm from the geometric center of the progressive-power lens is 30% or less.

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