JP6598695B2 - Eyeglass lenses - Google Patents

Description

  The present invention relates to a spectacle lens, and more particularly to a spectacle lens in which different prism components are set at the upper and lower portions of the lens.

  In near vision, a person inverts both eyes inward to concentrate the line of sight on one point in front of the eye. Such a function is called “congestion”. If the function of congestion is not sufficient, it becomes difficult to move the line of sight closer.

As a spectacle lens for assisting such congestion failure, for example, there are those described in Patent Document 1 and Patent Document 2 below. FIG. 8 shows an example. In the spectacle lens 100 shown in FIG. 8, an auxiliary lens 104 having a prism component having a base direction on the nose side (left side in the figure) is formed on a part (near-use area) on the outer surface (front surface) side of the main body lens 102. Has been.
By wearing such a spectacle lens, the line of sight in near vision can be bent flexibly to the nose due to the prism effect of the auxiliary lens 104. Effective in some cases.

However, when the auxiliary lens 104 is added to the front surface of the lens as in the spectacle lens 100 shown in FIG. 8, a step is generated at the boundary portion 106 between the auxiliary lens 104 and the main body lens 102, and the wearer's eyes when viewed from others are displayed. The problem that an external appearance is impaired arises.
In particular, when the prism amount of the auxiliary lens 104 is increased, the level difference at the boundary portion 106 is increased, and when the auxiliary lens 104 itself is increased, the peripheral length of the boundary portion 106 is increased. 106 becomes conspicuous, and it is difficult to achieve both the prism effect by the auxiliary lens 104 and the appearance.

Japanese Patent Laid-Open No. 5-303063 JP 2011-107298 A Japanese Patent No. 5442658 Japanese Patent No. 4996006

  The present invention is based on the above circumstances, and an object thereof is to provide a spectacle lens in which different prism components are set in the upper and lower portions of the lens and a clear boundary line does not appear between the upper and lower portions of the lens. It was made as.

Thus, claim 1 is a spectacle lens in which different prism components are set in the upper part and the lower part based on the surface shape of the inner surface, and the upper refractive power surface and the lower refractive power surface formed on the inner surface are , point-like contact only one coupling portion, the vertical direction of inclination of the upper power surface in the coupling portion and the lower power plane is the same, and the lower power side and the upper power plane but, in the relationship that has been twisted at one point of the coupling portion, the upper power plane and / or the lower power surface, the thickness of the lens outer surface is thick in either the nasal or temporal side, On the other hand, it is configured to be thin , a predetermined prism component is set in the upper part and / or the lower part, and the upper refractive power surface and the lower refractive power surface are between the upper refractive power surface and the lower refractive power surface. A curved interpolation surface that smoothly connects the lower refractive power surfaces. It is characterized by being.

  According to a second aspect of the present invention, in the first aspect, the boundary line between the upper refracting power surface and the interpolation surface is a straight left upper boundary line extending obliquely leftward from the coupling portion in the rear view, and the coupling portion. A straight right upper boundary line extending diagonally upward to the right, and a boundary line between the lower refractive power surface and the interpolation surface extending straight diagonally to the left from the coupling portion in a rear view. It is comprised from the lower boundary line and the linear right lower boundary line extended diagonally right below from the said connection part, It is characterized by the above-mentioned.

  A third aspect of the present invention is characterized in that, in any one of the first and second aspects, the inner surface is a double focal plane having different surface refractive powers on the upper refractive power surface and the lower refractive power surface. To do.

  [Claim 4] In any one of claims 1 and 2, the outer surface has a distance area used for viewing a distant object on the upper side and a near area used for viewing a near object on the lower side. Is a progressive refracting surface having a progressive area in which the power continuously changes between the distance area and the near area, so that the coupling portion overlaps the intermediate position of the progressive area in the front-rear direction. It is provided in.

  A fifth aspect of the present invention is characterized in that, in the fourth aspect, the inner surface is a double focal plane having different surface refractive powers on the upper refractive power surface and the lower refractive power surface.

  As described above, according to the present invention, different prism components are set for the upper and lower parts of the lens, and when the wearer moves the line of sight for far vision, or for near vision, When moved to the lower part, the line of sight can be corrected in the intended direction by the respective prism effects.

  In the present invention, regions having different prism components are provided above and below the coupling portion, respectively, and a predetermined prism effect can be obtained even when the line of sight is greatly moved in the vertical direction.

In addition, when an auxiliary lens is formed on the outer surface side of the lens as in the prior art, a step is produced at the boundary between the auxiliary lens and the lens body, and the appearance of the wearer when viewed by another person is impaired. However, in the present invention, since the prism component is set based on the surface shape of the lens inner surface, no boundary line is generated on the lens outer surface side. Further, the upper refractive power surface and the lower refractive power surface of the inner surface are in contact with only one point-like coupling portion, and the vertical inclination of the upper refractive power surface and the lower refractive power surface in the coupling portion is the same, Since a smooth interpolation surface is provided between the upper refractive power surface and the lower refractive power surface, a clear boundary line does not appear between the upper refractive power surface and the lower refractive power surface, and the appearance of the wearer is impaired. This can be prevented well.
Moreover, the discomfort felt by the wearer himself / herself due to the boundary lines and steps can be eliminated or reduced.

In the present invention, the boundary line between the upper refractive power surface and the interpolation surface is divided into a straight left upper boundary line extending diagonally to the left from the coupling portion and a linear right upper boundary line extending diagonally upward to the right from the coupling portion. A boundary line between the lower refractive power surface and the interpolation surface, a straight left lower boundary line extending diagonally to the left from the coupling part, and a linear right lower boundary line extending diagonally downward to the right from the coupling part. (Claim 2).
In this case, the size of the interpolation plane is determined by the angle of the left upper boundary line, the right upper boundary line, the left lower boundary line, and the right lower boundary line with respect to the axis extending in the left-right direction through the coupling portion. The For example, when a large amount of prism is set at the lower part of the lens, the difference in thickness between the upper part of the lens and the lower part of the lens becomes large, but by increasing the angle and setting the interpolation surface larger at the design stage, It is possible to prevent a clear boundary line from appearing between the lower refractive power surface.

In the present invention, the lens inner surface is a double focal plane having different surface refractive powers on the upper refractive power surface and the lower refractive power surface, so that the distance in the distance portion (upper portion) and the near portion (lower portion) can be reduced. In addition, a bifocal lens having different prism components can be provided.
Also in the third aspect, since a smooth interpolation surface is provided between the upper refractive power surface and the lower refractive power surface, a clear boundary line does not appear between the distance portion and the near portion, and the wearer's It is possible to prevent the appearance from being damaged.

  In the present invention, the outer surface is continuously used between a distance area used for viewing a distant object, a near area used for viewing a near object, and the distance area and the near area. A progressive refracting surface having a progressive region with a variable power, and by providing a coupling portion so as to overlap with the intermediate position of the progressive region in the front-rear direction, the prism component together with the power in the distance portion and the near portion It is possible to provide progressive power lenses having different (claim 4).

A progressive-power lens is characterized by being able to visually recognize an intermediate distance lens at a middle portion (progressive region) with respect to a bifocal lens, but the surface shape of the progressive-power surface is changed. When a specific prism component is added to the upper part or the lower part of the lens, the entire intermediate part is twisted, and the clear vision region of the intermediate part is crushed by the aberration.
On the other hand, in claim 4, the lens outer surface is a progressive refractive surface, while the upper refractive surface or the lower refractive surface is twisted at one point of the coupling portion of the inner surface of the lens so that only a specific prism is formed on the upper or lower portion of the lens. Since components can be added, the occurrence of aberrations at the intermediate portion can be minimized.

When constructing a progressive addition lens, the outer surface is a progressive addition surface, while the inner surface of the lens is a double focal plane having different surface refractive powers on the upper and lower refractive surfaces. A part of the addition planned as can be set on the double focal plane side. (Claim 5).
By doing in this way, a frequency change can be enlarged by the point of the coupling part located in the middle of the progressive area. This makes it possible to switch between far-distance and near-distance with less eye movement / rotation amount than a conventional progressive-power lens, thereby reducing fatigue.
In order to secure a clear vision region in the intermediate portion, it is desirable that the addition on the progressive surface of the outer surface be larger than the addition on the double focal plane on the inner surface.

  According to the present invention as described above, it is possible to provide a spectacle lens in which different prism components are set in the upper part and the lower part of the lens and no clear boundary line appears between the upper part and the lower part of the lens.

It is the figure which showed the spectacle lens of one Embodiment of this invention. (A) It is upper part sectional drawing of the spectacle lens of the embodiment. (B) It is a lower section of the spectacle lens of the embodiment. It is explanatory drawing of the interpolation surface production | generation method in the spectacle lens of the embodiment. It is a figure for demonstrating the effect of the spectacles lens of the embodiment. It is the figure which showed the spectacle lens of other embodiment of this invention. It is the figure which showed the clear vision area | region in the spectacle lens of the embodiment with the comparative example. It is the figure which showed the power change of the Example when the total addition power is 2.00D, and the comparative example which is a conventional progressive-power lens. It is the figure which showed an example of the conventional spectacle lens with an auxiliary lens.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the front / rear, left / right, and upper / lower for the wearer when wearing spectacles using the lens are referred to as the front / rear, left / right, and upper / lower, respectively, of the lens.

In FIG. 1, a spectacle lens 10 (hereinafter sometimes referred to simply as a lens) has a prism component that assists the movement of the line of sight in near vision at the bottom of a single focus lens.
The front surface of the lens 10 has a spherical shape, and an upper refractive surface 11 is formed on the upper side of the lens inner surface (rear surface), and a lower refractive surface 12 is formed on the lower side.

The upper refracting power surface 11 and the lower refracting power surface 12 on the inner surface of the lens are in contact with each other at only one dotted coupling portion 13, and the upper and lower refractive power surfaces 11 and 12 are inclined in the vertical direction at the coupling portion 13. Are the same.
Between the upper refractive power surface 11 and the lower refractive power surface 12, a curved interpolation surface 16 that smoothly connects the upper refractive power surface 11 and the lower refractive power surface 12 (see the hatched portion in FIG. 1B). It is said that.
The interpolation surface 16 is a surface that causes astigmatism. Hereinafter, in the lens 10, the portion where the lens inner surface is the interpolation surface 16 is the astigmatism portion 26, the portion where the upper refractive power surface 11 is the upper portion 21, and the lower refraction. A portion that is the force surface 12 is a lower portion 22.

2A shows a lens cross-sectional shape at the upper portion 21 of the lens 10, and FIG. 2B shows a lens cross-sectional shape at the lower portion 22.
In this example, a specific prism component is not set in the upper portion 21 of the lens 10, and a prism component having a base direction on the nose side is set only in the lower portion 22 of the lens 10. For this reason, as shown in FIG. 2A, the upper refractive surface 11 of the lens inner surface is formed symmetrically with respect to the Z axis indicating the front-rear direction in the upper portion 21, while as shown in FIG. In the lower portion 22 of the lens 10, the entire lower refractive power surface 12 is anteroposteriorly so that the thickness of the lower refractive surface 12 and the front surface of the lens is thick on the nose side (left side in the figure) and thin on the ear side (right side in the figure). It is inclined to.
Therefore, in this example, when the surface shapes of the upper refractive power surface 11 and the lower refractive power surface 12 are compared, the positions in the front-rear direction are different from each other in the vicinity of the edge in the left-right direction. 11 and the lower refractive power surface 12 are smoothly connected by the interpolation surface 16, so that no clear boundary line is generated between the upper refractive power surface 11 and the lower refractive power surface 12.

  Next, a method for designing the lens 10 will be described. The method for determining the upper refractive power surface 11, the lower refractive power surface 12, and the interpolation surface 16 based on a given prescription power is described in detail in the above-mentioned Patent Document 3, and is not described in detail here. The refractive power surface of the lens outer surface and the upper refractive power surface 11 and the lower refractive power surface 12 of the lens inner surface are determined based on the prescription power of the person.

Next, as shown in FIG. 1B, the coupling portion 13 is set at a position lower than the geometric center O by δ in the Y-axis direction, and Z of the upper refractive power surface 11 and the lower refractive power surface 12 in the coupling portion 13 is determined. The coordinate value and the inclination in the Y-axis direction are calculated, and the respective differences are obtained. Then, the lower refractive power surface 12 is moved in the Z-axis direction and tilted with respect to the upper refractive power surface 11 so as to eliminate the difference therebetween.
In addition, in this example, the lower refractive power surface 12 is twisted at one point of the coupling portion 13 on the inner surface of the lens so that a prism component that assists the movement of the line of sight in near vision is obtained at the lower portion 22 of the lens 10. The outer surface of the lens should be thicker on the nose side and thinner on the ear side.
In this example, as shown in FIG. 1, the axis extending in the left-right direction through the geometric center O of the lens 10 is the X axis, the axis extending in the vertical direction through the geometric center O is the Y axis, and the geometric center O. An axis that passes through and is orthogonal to the X axis and the Y axis is taken as the Z axis.

Then, as shown in FIG. 1B, in the rear view, the left upper boundary line 14L and the right upper boundary line 14R (when collectively referred to as “upper boundary line 14”) 13, straight lines extending obliquely upward to the left and obliquely upward to the right are formed at a predetermined angle θ ₁ with respect to the axis A parallel to the X axis through the coupling portion 13. Further, the left lower boundary line 15L and the right lower boundary line 15R (referred to as “lower boundary line 15” when collectively referred to) are set at a predetermined angle θ ₂ from the coupling portion 13 to the axis A. Therefore, it is a straight line extending diagonally downward to the left and diagonally downward to the right. Here, the angles θ ₁ and θ ₂ are collectively referred to as “inner surface angle”.

Next, as shown in FIG. 3, the first point P ₁ on the upper boundary line 14 and the second point having the same X coordinate as the first point P ₁ and a slightly larger Y coordinate (1 mm in this case). P ₀ , the third point P ₂ on the lower boundary 15 where the first point P ₁ and the X coordinate are the same, and the third point P ₂ and the X coordinate are the same and the Y coordinate is slightly (here 1 mm) ) Calculate the respective Z coordinates for the small fourth point P ₃ . It is assumed that the Y coordinate increases upward. Then, a curve passing through these four points is obtained by the N-spline interpolation method, a portion between the _first point P ₁ and the third point P ₂ of the curve is set as an interpolation line, and an interval in the X-axis direction is predetermined. Interpolation lines are generated with a short interval of 1 mm (here, 1 mm), and a plane obtained by connecting these interpolation lines is defined as an interpolation plane 16.

  Next, a method for manufacturing the lens 10 will be described. First, a space surrounded by the upper mold and the lower mold is filled with a liquid thermosetting synthetic resin and heated to solidify, thereby obtaining a semi-finished product that becomes a precursor of the lens 10. The lower surface of the upper mold has a concave shape corresponding to the refracting power surface of the outer surface to be obtained, and an outer refracting surface is formed on the upper surface of the semi-finished product at the stage of the semi-finished product. Since the lower mold has a spherical shape whose upper surface is convex upward, the lower surface of the semi-finished product has a concave spherical shape.

  Next, the inner surface of the lens 10 is formed by cutting the lower surface of the semi-finished product so as to become the upper refractive power surface 11, the lower refractive power surface 12, and the interpolation surface 16 designed as described above. A predetermined prism component is given to the lower part 22 of the lens 10 together with the prescription power based on the surface shape of the inner surface formed by the cutting process at this time.

  In the lens 10 of this embodiment designed and manufactured in this way, a prism component having a base direction on the nose side is set only at the lower portion 22 of the lens 10. For this reason, as shown in FIG. 4 (A), when the wearer moves his / her line of sight above the lens 10 for far vision, the line of sight is directed to the front of the front through the upper part 21 of the lens 10 as usual, and a far object Can be visually recognized. On the other hand, as shown in FIG. 4B, when the wearer moves the line of sight downward for near vision, the direction of the line of sight is bent inward through the lower part 22 of the lens 10 in which the prism component is set. Therefore, it is possible to visually recognize a near object without forcing both eyes inward.

  In the present embodiment, since a predetermined prism component is provided on the entire surface of the lower part 22 of the lens up to the lower edge of the lens, a predetermined prism effect can be obtained even when the line of sight is greatly moved downward. it can.

  In this embodiment, since the prism component is set based on the surface shape of the lens inner surface, no boundary line is generated on the lens outer surface side. Further, the upper refractive power surface 11 and the lower refractive power surface 12 on the inner surface of the lens are in contact with only one point-like coupling portion 13, and the upper refractive power surface 11 and the lower refractive power surface 12 in the coupling portion 13 in the vertical direction. Since the inclination is the same and the smooth interpolating surface 16 is provided between the upper refractive power surface 11 and the lower refractive power surface 12, a clear boundary is formed between the upper refractive power surface 11 and the lower refractive power surface 12. The line does not appear, and it is possible to satisfactorily prevent the appearance of the wearer from being damaged.

Further, in the present embodiment, the boundary line between the upper refractive power surface 11 and the interpolation surface 16 includes a straight left upper boundary line 14L extending diagonally left upward from the coupling portion 13 and a straight line extending diagonally right upward from the coupling portion 13. A right-side upper boundary line 14R, and a boundary line between the lower refractive power surface 12 and the interpolation surface 16 is a straight left-side lower boundary line 15L extending obliquely downward to the left from the coupling portion 13; The left upper boundary line 14L and the upper right side with respect to the axis A extending in the left-right direction through the coupling portion 13 are configured with a straight right lower boundary line 15R extending diagonally downward to the right. The size of the interpolation surface 16 is determined by the inclinations (inner surface angles θ ₁ , θ ₂ ) of the boundary line 14R, the left lower boundary line 15L, and the right lower boundary line 15R.
For example, when a large prism amount is set only for the lower portion 22 of the lens 10, the difference in thickness between the upper portion 21 and the lower portion 22 of the lens increases, but interpolation is performed by increasing the inner surface angles θ ₁ and θ ₂ at the design stage. By setting the surface 16 wide, it is possible to prevent a clear boundary line from appearing between the upper refractive power surface 11 and the lower refractive power surface 12.

  In this embodiment, the prism component is set at the lower part of the single focus lens. However, the upper refractive power surface 11 and the lower refractive power surface 12 have different surface refractive powers, and the inner surface of the lens is doubled. If the focal plane is used, it is possible to provide a bifocal lens having different prism amounts as well as power in the distance portion (upper portion 21) and the near portion (lower portion 22).

FIG. 5 is a view showing a spectacle lens according to another embodiment of the present invention.
In the spectacle lens 30 according to the embodiment, a prism component that assists the movement of the line of sight in near vision is set below the progressive addition lens.
This lens 30 has a distance portion 31 used for viewing a distant object on the upper side, a near portion 32 used for viewing a near object on the lower side, a distance portion 31 and a near portion 32 It is set as the structure provided with the intermediate part 33 from which a frequency changes between.

  The outer surface (front surface) 35 of the lens 30 has a distance area 41 used for viewing a distant object on the upper side, and a near area 42 used for viewing a near object on the lower side. And the near region 42 are provided with a progressive region 43 whose power continuously changes, and by making the near region 42 inward on the nose side, a progressive refractive surface that is asymmetrical on the left and right of the center line is obtained. ing.

  Specifically, the outer surface 35 is a progressive refracting surface described in Patent Document 4 described above, that is, in the orthogonal coordinate system, Z given as Z = F (X, Y) is continuously connected by the following formula [Equation 1] Is an n-th power function selected from the range of n = 8 to 20 (preferably n = 11 to 15), and an odd-order term of X and an odd-order term of Y The surface is composed of power functions to be included. More specifically, the order of the power function is n = 13.

  It should be noted that by repeatedly setting the expression of the outer surface 35 while changing the coefficient Aab so as to satisfy the given power addition condition, the coefficient Aab that finally satisfies the given condition is determined, and the outer surface 35 is determined. It becomes.

Further, as shown in FIG. 5B, the inner surface (rear surface) 36 of the lens 30 is formed with an upper refractive power surface 51 on the upper side and a lower refractive power surface 52 on the lower side. In this example, the upper refractive power surface 51 and the lower refractive power surface 52 have different surface refractive powers, and the inner surface 36 of the lens is a double focal plane.
Further, in this example, a specific prism component is not set on the upper portion of the lens 30 (that is, the portion where the inner surface 36 is the upper refractive power surface 51), and the lower portion of the lens 10 (that is, the portion where the inner surface 36 is the lower refractive power surface 52). ) Only has a prism component with a base direction on the nose side. Therefore, similarly to the lower refractive power surface 12 shown in FIG. 2B, the lower refractive power is set so that the thickness with the lens front surface 35 is thicker on the nose side and thinner on the ear side (right side in the figure). The entire surface 52 is inclined in the front-rear direction.

  As shown in FIG. 5B, the upper refracting power surface 51 and the lower refracting power surface 52 are in contact with only one point-like coupling portion 53, and the upper refracting power surface 51 and the lower refracting power surface in the linking portion 53 are in contact with each other. The vertical inclination of 52 is the same, and between the upper refractive power surface 51 and the lower refractive power surface 52, a curved interpolation surface that smoothly connects the upper refractive power surface 51 and the lower refractive power surface 52. 54 (see the hatched portion in FIG. 5B).

The method for determining the upper refractive power surface 51, the lower refractive power surface 52, and the interpolation surface 54 based on the given prescription power is the same as in the first embodiment.
However, the connecting portion 53 is set at a position lower than the geometric center O by δ in the Y-axis direction so that the connecting portion 53 overlaps the middle position of the progressive region 43 of the outer surface 35 in the front-rear direction. For example, in a lens in which a progressive zone length of 12 mm is set downward from the geometric center O, a coupling portion 53 is provided at a position where δ in FIG.
Then, the Z coordinate value and the inclination in the Y-axis direction of the upper refracting power surface 51 and the lower refracting power surface 52 in the coupling portion 53 are calculated, and the respective differences are obtained. Then, the lower refractive power surface 52 is moved in the Z-axis direction and tilted with respect to the upper refractive power surface 51 so as to eliminate the difference therebetween.
In addition, in this example, the lower refractive power surface 52 is twisted at one point of the coupling portion 53 on the inner surface of the lens so that a prism component that assists the movement of the line of sight in near vision is obtained at the lower portion of the lens 30. The thickness with the lens outer surface 35 is made thick on the nose side and thin on the ear side.
The upper refracting power surface 51 and the lower refracting power surface 52 are connected by an interpolation surface 54 using the same method as in the first embodiment.

  In the lens 30, the addition on the progressive refraction surface of the outer surface 35 (hereinafter referred to as “outer surface addition”) is greater than the addition on the double focal plane of the inner surface 36 (hereinafter referred to as “inner surface addition”). Has also been enlarged. The inside addition is obtained by subtracting the outside addition from the addition desired to be obtained as a whole (hereinafter referred to as “total addition”). This is because the astigmatism region is reduced and the clear vision region of the intermediate portion 33 is enlarged when the inner surface addition is suppressed.

  Furthermore, in the lens 30, the inner surface addition power is set to 0.75D or less. This is because when the addition to the inner surface is greater than 0.75D, the reduction effect of the astigmatism region is small, and the appearance of the intermediate portion 33 is likely to be poor. Table 1 shows an example of the outer surface addition and the inner surface addition with respect to the total addition set at 0.25D intervals from 1.00D to 4.25D. However, for example, when the total addition is 1.25D, the external addition is 1.00D, the internal addition is 0.25D, or when the total addition is 2.00D, the external addition is It is good also as addition power settings other than what is shown in Table 1, such as 1.50D and internal surface addition power 0.50D. In Table 1, the outer surface addition is 0.25D or more larger than the inner surface addition because the addition is set in increments of 0.25D.

  Further, when the lens 30 is manufactured, a progressive refraction surface of the outer surface 35 is formed on the upper surface of the semi-finished product at the stage of obtaining a semi-finished product that is a precursor of the lens 30. In addition, 12 types of upper molds corresponding to 0.25D intervals from 0.75D to 3.50D addition of the progressive refractive surface are prepared for each type of base curve. Since the lower mold is one kind of spherical shape whose upper surface is convex upward, the lower surface of the semi-finished product has a concave spherical shape.

  Next, the lower surface of the semi-finished product is cut so that it becomes a double focal plane composed of the upper refractive power surface 51, the lower refractive power surface 52, and the interpolation surface 54 designed as described above, thereby the lens 30. The inner surface 36 is formed. A predetermined prism component is given to the lower portion of the lens 30 together with the prescription power based on the surface shape of the inner surface formed by the cutting process at this time.

  As described above, in the lens 30, the outer surface 35 is a progressive refractive surface, and the inner surface 36 has a seamless boundary line between the upper refractive power surface 51 and the lower refractive power surface 52. It is regarded as a heavy focal plane. Therefore, a clear boundary line does not appear on either the outer surface 35 or the inner surface 36, and the possibility of impairing the appearance of the wearer is reduced.

FIG. 6 is a diagram schematically showing changes in the clear vision region when a specific prism component is added only to the lower part of the progressive-power lens. In the figure, the white background portion is a clear vision region.
FIG. 6A shows a clear vision region in a conventional progressive power lens in which a progressive refractive surface is formed. In this case, if the surface shape of the lens is changed to add a specific prism component only to the lower portion of the lens, the entire intermediate portion 33 is twisted, and the clear vision region of the intermediate portion 33 becomes larger as shown in FIG. It collapses due to aberrations.
On the other hand, in the present embodiment, a specific prism component can be added only to the lower part of the lens by twisting the lower refractive surface 52 at one point of the coupling part 53 on the inner surface of the lens, so that it is shown in FIG. Thus, it is possible to minimize the occurrence of aberration in the intermediate portion 33.

FIG. 7 is a diagram showing the power change at the center line in the longitudinal direction of the lens when the total addition power is 2.00 D and the comparative example which is a conventional progressive-power lens.
This embodiment (solid line) is a progressive addition lens having a progressive zone length of 12 mm, and the addition power on the progressive addition surface is 1.25D and the addition power on the bifocal plane is 0.75D with respect to the total addition power 2.00D. In the comparative example (broken line), the addition power is 2.00 D with only the progressive refractive surface.
As shown in the figure, in this embodiment, the frequency change is gentle in the vicinity of the geometric center O where the progressive region begins, and the front view is easy. Further, the addition power is larger than that of the comparative example below the point corresponding to the position of the coupling portion 53 that is 7 mm below the geometric center O. That is, the near portion 32 is enlarged upward. Therefore, in the embodiment, it is possible to switch between the distance use and the near use with less eye movement / rotation amount than in the comparative example.

The above embodiment is an example in which a prism component having a base direction on the nose side is set only at the lower part of the lens for the purpose of assisting movement in near vision. When the eyeball is difficult to return to the outside (ear side), that is, when the divergence is weak, a prism component with the base direction on the ear side is set only at the top of the lens for the purpose of assisting movement during distance vision It is also possible to do.
In addition, when the astigmatism power is prescribed, the present invention can be implemented in various forms without departing from the gist of the present invention, such as adding an astigmatism power component to the inner surface of the lens.

10, 30 Eyeglass lens 11, 51 Upper refractive surface 12, 52 Lower refractive surface 13, 53 Coupling portion 14L, 14R Upper boundary line 15L, 15R Lower boundary line 16, 54 Interpolation surface 21 Upper portion 22 Lower portion 35 Outer surface 36 Inner surface 41 Far area 42 Near area 43 Progressive area

Claims (5)

A spectacle lens in which different prism components are set in the upper part and the lower part based on the surface shape of the inner surface,
The upper refracting power surface and the lower refracting power surface formed on the inner surface are in contact with only one point-like coupling portion, and the vertical inclination of the upper refracting power surface and the lower refracting power surface at the coupling portion is The upper refractive power surface and the lower refractive power surface are twisted at one point of the coupling portion, and the upper refractive power surface and / or the lower refractive power surface is a lens. The outer surface is configured to be thicker on either the nose side or the ear side and thinner on the other side, and a predetermined prism component is set on the upper part and / or the lower part,
The spectacle lens, wherein a curved interpolation surface that smoothly connects the upper refractive power surface and the lower refractive power surface is formed between the upper refractive power surface and the lower refractive power surface.
A boundary line between the upper refracting power surface and the interpolation surface is a straight left upper boundary line extending diagonally to the left from the coupling part and a linear right side extending diagonally upward to the right from the coupling part in rear view. It consists of an upper border and
A boundary line between the lower refractive power surface and the interpolation surface is a straight left lower boundary line extending diagonally to the left from the coupling portion and a straight right side extending diagonally downward to the right from the coupling portion in rear view. The spectacle lens according to claim 1, comprising a lower boundary line.   The spectacle lens according to claim 1, wherein the inner surface is a bifocal surface having different surface refractive powers on the upper refractive power surface and the lower refractive power surface. The distance between the distance area and the near area is a distance area that is used to see a distant object on the upper side and a near area that is used to see a near object on the lower side. It is a progressive refracting surface with a progressive region whose power changes continuously,
The spectacle lens according to claim 1, wherein the coupling portion is provided so as to overlap with a midway position of the progressive region in the front-rear direction.   The spectacle lens according to claim 4, wherein the inner surface is a bifocal surface having different surface refractive powers on the upper refractive power surface and the lower refractive power surface.

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