US20010030735A1 - Progressive power spectacle lens - Google Patents
Progressive power spectacle lens Download PDFInfo
- Publication number
- US20010030735A1 US20010030735A1 US09/271,454 US27145499A US2001030735A1 US 20010030735 A1 US20010030735 A1 US 20010030735A1 US 27145499 A US27145499 A US 27145499A US 2001030735 A1 US2001030735 A1 US 2001030735A1
- Authority
- US
- United States
- Prior art keywords
- distance
- progressive
- surface astigmatism
- main meridian
- spectacle lens
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
- G02C7/00—Optical parts
- G02C7/02—Lenses; Lens systems ; Methods of designing lenses
- G02C7/06—Lenses; Lens systems ; Methods of designing lenses bifocal; multifocal ; progressive
-
- G—PHYSICS
- G02—OPTICS
- G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
- G02C7/00—Optical parts
- G02C7/02—Lenses; Lens systems ; Methods of designing lenses
- G02C7/06—Lenses; Lens systems ; Methods of designing lenses bifocal; multifocal ; progressive
- G02C7/061—Spectacle lenses with progressively varying focal power
- G02C7/063—Shape of the progressive surface
- G02C7/065—Properties on the principal line
-
- G—PHYSICS
- G02—OPTICS
- G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
- G02C7/00—Optical parts
- G02C7/02—Lenses; Lens systems ; Methods of designing lenses
- G02C7/06—Lenses; Lens systems ; Methods of designing lenses bifocal; multifocal ; progressive
- G02C7/061—Spectacle lenses with progressively varying focal power
Definitions
- the present invention relates to a progressive power spectacle lens with a dioptric power varying progressively between a distance portion and a near portion.
- FIG. 17 is a front view (viewed from an object side) of a progressive power spectacle lens 1 for a right eye.
- the lens 1 includes:
- a near portion 3 having a dioptric power for near vision at a lower area of the lens [0004] a near portion 3 having a dioptric power for near vision at a lower area of the lens
- a dioptric power in the intermediate portion 4 progressively varies from the upper portion to the lower portion.
- Such a power is given by the asymmetrical shape formed on the front or rear surface, which is referred to as a progressive side surface.
- a rectangular coordinate is defined by a fitting point O as an origin, a horizontal X-axis, and a vertical Y-axis.
- the fitting point O is the point on the progressive side surface of the lens 1 determined by a manufacturer as a reference point for positioning the lens in front of the eye.
- the power of the progressive side surface varies along a main meridian MM′ that is a virtual centerline extending substantially along the vertical direction.
- the main meridian MM′ is coincident with the Y-axis in the distance portion 2 , while it is bent toward a nasal side in the intermediate portion 4 , and extends vertically with being shifted toward the nasal side in the near portion 3 by an amount Xm.
- the progressive power spectacle lens 1 must include surface astigmatism on the progressive side surface since the distance portion and the near portion, which have different dioptric powers, are smoothly connected.
- a zone along the main meridian MM′ is a center of a view field of a user, and accordingly, it is desirable that the astigmatism along the main meridian MM′ is minimized in order to provide a clear vision zone.
- the clear vision zone is a zone through which a user obtains a natural and comfortable view.
- the main meridian MM′ is designed as an umbilical line along which a surface astigmatism has a value of zero.
- a progressive power lens is designed with a surface performance evaluation of a progressive side surface (referred hereinafter as “a surface evaluating design”) to reduce complicated and expensive calculation work.
- the lens having the umbilical main meridian results in good performance in terms of the surface performance evaluation.
- the lens having a good surface performance does not always have a good transmission performance in a transmitting performance evaluation using the ray-tracing method.
- the transmission performance (which corresponds to a worn condition) is more important than the surface performance for actual products.
- a surface astigmatism is an absolute value of the difference between the dioptric power of the progressive side surface in a maximum curvature direction where the curvature has the maximum value, and the dioptric power of the surface in a direction where the curvature has the minimum value.
- the surface astigmatism is only determined by the shape of the progressive side surface.
- a resultant astigmatism is an astigmatism caused on a fundus of an eye through the lens.
- the transmission performance is substantially coincident with the surface performance. This means that the good transmission performance lens can be designed by the surface evaluating design. However, the large curvature of the lens results in a heavy and thick lens.
- Japanese provisional patent publication Nos. SHO 59-58415, HEI 1-221722, HEI 8-136868 and HEI 4-500870 disclose the progressive power spectacle lenses that have non-umbilical main meridians. Although each of the publications teaches the surface astigmatism along the main meridian, none of the publications disclose the variation of the surface astigmatism along the horizontal direction.
- a progressive power spectacle lens which includes:
- a predetermined surface astigmatism is provided on a main meridian, and the surface astigmatism decreases and then increases as the distance from the main meridian increases in a horizontal direction within the near portion.
- the variation of the surface astigmatism is desirable to satisfy the condition (1) on at least one point in the range of ⁇ 30 ⁇ Y ⁇ 15, and further to satisfy the condition (2) on at least one point in the overlapped range of ⁇ 30 ⁇ Y ⁇ 15 and 3 ⁇
- AS(x, y) is the surface astigmatism at the point (x, y), and
- the maximum curvature direction ⁇ (x, y) that is defined as an angle (unit: degree) with respect to the X-axis at the point (x, y) is desirable to satisfy the conditions (3) and (4);
- FIG. 1 is a map showing a surface astigmatism distribution on a progressive side surface of a spectacle lens according to a first embodiment
- FIG. 4 is a distribution map showing a resultant astigmatism distribution of the lens shown in FIG. 1;
- FIG. 5 is a distribution map of a surface astigmatism distribution on a progressive side surface of the spectacle lens according to a comparative example 1 that is not an embodiment
- FIG. 7 is a distribution map showing a resultant astigmatism distribution of the lens shown in FIG. 5;
- FIG. 8 is a distribution map showing a surface astigmatism distribution on a progressive side surface of the spectacle lens according to a second embodiment
- FIG. 11 is a distribution map showing a resultant astigmatism distribution of the lens shown in FIG. 8;
- FIG. 12 is a distribution map showing a surface astigmatism distribution on a progressive side surface of the spectacle lens according to a comparative example 2 that is not an embodiment
- FIG. 14 is a distribution map of a resultant astigmatism distribution of the lens shown in FIG. 12;
- FIG. 15 shows rectangular coordinates on a progressive power spectacle lens
- FIG. 16 is a graph showing the definition of the maximum curvature direction.
- FIG. 17 shows a general distribution of portions on the progressive side surface of a progressive power spectacle lens.
- the progressive power spectacle lens according to each of the embodiments includes a distance portion having a dioptric power for distance vision, a near portion having a dioptric power for near vision, and an intermediate portion having a progressive dioptric power for vision at ranges intermediate between distance and near portions.
- a main meridian is not an umbilical line.
- a predetermined surface astigmatism is provided on the main meridian as defined by condition (1) on at least one point in the range of ⁇ 30 ⁇ Y ⁇ 15 when a rectangular coordinate (unit: mm) is defined by a fitting point O as an origin, a horizontal X-axis, and a vertical Y-axis;
- AS(x, y) is the surface astigmatism at the point (x, y), and
- FIG. 15 shows the rectangular coordinate on the progressive power spectacle lens.
- the range of ⁇ 30 ⁇ Y ⁇ 15 is indicated by “A”.
- the surface astigmatism decreases and then increases as the distance from the main meridian MM′ increases in a horizontal direction (i.e., in the X-axis direction) within a clear vision zone.
- Such a distribution of the surface astigmatism is effective to enlarge the width of the clear vision zone.
- the variation of the surface astigmatism satisfies condition (2) on at least one point in the overlapped range of ⁇ 30 ⁇ Y ⁇ 15 and 3 ⁇
- ⁇ 10 is indicated by “B”.
- Condition (2) is satisfied in the ranges (shown by hatching) where the ranges A and B overlap.
- the range B may be limited to 5 ⁇
- the maximum curvature direction ⁇ (x, y) that is defined as an angle (unit: degree) with respect to the X-axis at the point (x, y) satisfies conditions (3) and (4);
- the dioptric power at a point on the progressive side surface can be described as an ellipse as shown in FIG. 16.
- the size of the ellipse indicates the dioptric power at the point (x, y).
- the point having the surface astigmatism is indicated by an ellipse, while an umbilical point is indicated by a circle.
- a major axis Cmax of the eclipse represents the direction of the maximum curvature thereof, and the angle of the major axis Cmax with respect to the X-axis is the maximum curvature direction ⁇ (x, y).
- Condition (3) requires that the maximum curvature direction on the main meridian MM′ is substantially parallel to the horizontal direction (X-axis), and condition (4) requires that the maximum curvature direction at the points distant from the main meridian by ⁇ 10 mm is substantially perpendicular to the horizontal direction.
- FIG. 1 is a map of a surface astigmatism distribution on a progressive side surface of the progressive power spectacle lens according to the first embodiment. Specifications of the lens are as follows:
- the near portion of the lens includes a zone C (shown by hatching) in which the surface astigmatism is larger than 0.20 [D] along the main meridian MM′.
- the displacement Xm is equal to 2.5 mm in a range of ⁇ 40 ⁇ Y ⁇ 19.
- FIGS. 2 and 3 are graphs showing a variation of the surface astigmatism AS(X, ⁇ 25) and a variation of the maximum curvature direction ⁇ (X, ⁇ 25) of the lens shown in FIG. 1 respectively.
- the surface astigmatism decreases and then increases as the distance from the main meridian MM′ increases within the clear vision zone.
- the maximum curvature direction varies along the horizontal direction as a monotonic function as shown in FIG. 3.
- the first embodiment satisfies conditions (1) though (4) as follows.
- FIG. 4 A distribution of the resultant astigmatism, which is obtained by the transmitting evaluation, according to the first embodiment is shown in FIG. 4.
- the width of the clear vision zone S, in which the resultant astigmatism is lower than 0.5, is equal to 11 mm.
- FIG. 5 shows a map of a surface astigmatism distribution on a progressive side surface of the comparative example 1. This example is described for indicating the compared effect of the first embodiment and it is not an embodiment of the invention.
- the lens of the example 1 has the same specification as the first embodiment in the base curve, SPH and the additional power, while the lens is designed so that the surface performance is optimized. That is, the main meridian is designed as an umbilical line.
- FIG. 6 is a graph showing a variation of the surface astigmatism AS (X, ⁇ 25) of the lens shown in FIG. 5. As shown in FIG. 6, the surface astigmatism is almost equal to zero on the main meridian MM′ and it monotonically increases as the distance from the main meridian MM′ increases.
- FIG. 7 A distribution of the resultant astigmatism according to the example 1 is shown in FIG. 7.
- the width of the clear vision zone s is 4 mm.
- FIG. 8 is a map of a surface astigmatism distribution on a progressive side surface of the progressive power spectacle lens according to the second embodiment. Specifications of the lens are as follows:
- the near portion of the lens includes a zone D (shown by hatching) in which the surface astigmatism is larger than 0.20 [D] along the main meridian MM′.
- the displacement Xm is equal to 2.5 mm in a range of ⁇ 40 ⁇ Y ⁇ 19.
- FIGS. 9 and 10 are graphs showing a variation of the surface astigmatism AS (X, ⁇ 25) and a variation of the maximum curvature direction ⁇ (X, ⁇ 25) of the lens shown in FIG. 8 respectively.
- the surface astigmatism decreases and then increases as the distance from the main meridian MM′ increases within the clear vision zone.
- the maximum curvature direction varies along the horizontal direction as a monotonic function as shown in FIG. 10.
- the second embodiment satisfies the conditions (1) though (4) as follows.
- FIG. 11 A distribution of the resultant astigmatism, which is obtained by the transmitting evaluation, according to the second embodiment is shown in FIG. 11.
- the width of the clear vision zone s is equal to 12 mm.
- FIG. 12 shows a map of a surface astigmatism distribution on a progressive side surface of the comparative example 2.
- the lens of the example 2 has the same specification as the second embodiment in the base curve, SPH and the additional power, while the lens is designed so that the surface performance is optimized. That is, the main meridian is designed as an umbilical line.
- FIG. 13 is a graph showing a variation of the surface astigmatism AS(X, ⁇ 25) of the lens shown in FIG. 12. As shown in FIG. 13, the surface astigmatism is almost equal to zero on the main meridian MM′ and it monotonically increases as the distance from the main meridian MM′ increases.
- FIG. 14 A distribution of the resultant astigmatism according to the example 2 is shown in FIG. 14.
- the clear vision zone is limited at only the center portion of the lens.
- the width of the clear vision zone s is 7 mm.
Landscapes
- Health & Medical Sciences (AREA)
- Ophthalmology & Optometry (AREA)
- Physics & Mathematics (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Eyeglasses (AREA)
Abstract
Description
- The present invention relates to a progressive power spectacle lens with a dioptric power varying progressively between a distance portion and a near portion.
- FIG. 17 is a front view (viewed from an object side) of a progressive
power spectacle lens 1 for a right eye. Thelens 1 includes: - a
distance portion 2 having a dioptric power for distance vision at an upper area of the lens; - a
near portion 3 having a dioptric power for near vision at a lower area of the lens; and - an intermediate portion4 between the near and distance portions.
- A dioptric power in the intermediate portion4 progressively varies from the upper portion to the lower portion. Such a power is given by the asymmetrical shape formed on the front or rear surface, which is referred to as a progressive side surface.
- A rectangular coordinate is defined by a fitting point O as an origin, a horizontal X-axis, and a vertical Y-axis. The fitting point O is the point on the progressive side surface of the
lens 1 determined by a manufacturer as a reference point for positioning the lens in front of the eye. - The power of the progressive side surface varies along a main meridian MM′ that is a virtual centerline extending substantially along the vertical direction. Specifically, the main meridian MM′ is coincident with the Y-axis in the
distance portion 2, while it is bent toward a nasal side in the intermediate portion 4, and extends vertically with being shifted toward the nasal side in thenear portion 3 by an amount Xm. - The progressive
power spectacle lens 1 must include surface astigmatism on the progressive side surface since the distance portion and the near portion, which have different dioptric powers, are smoothly connected. In particular, a zone along the main meridian MM′ is a center of a view field of a user, and accordingly, it is desirable that the astigmatism along the main meridian MM′ is minimized in order to provide a clear vision zone. The clear vision zone is a zone through which a user obtains a natural and comfortable view. - In one type of the conventional progressive power lenses, the main meridian MM′ is designed as an umbilical line along which a surface astigmatism has a value of zero.
- Conventionally, a progressive power lens is designed with a surface performance evaluation of a progressive side surface (referred hereinafter as “a surface evaluating design”) to reduce complicated and expensive calculation work. The lens having the umbilical main meridian results in good performance in terms of the surface performance evaluation. However, the lens having a good surface performance does not always have a good transmission performance in a transmitting performance evaluation using the ray-tracing method. The transmission performance (which corresponds to a worn condition) is more important than the surface performance for actual products.
- It should be noted that two types of astigmatism are used in the specification. “A surface astigmatism” is an absolute value of the difference between the dioptric power of the progressive side surface in a maximum curvature direction where the curvature has the maximum value, and the dioptric power of the surface in a direction where the curvature has the minimum value. The surface astigmatism is only determined by the shape of the progressive side surface. On the other hand, “a resultant astigmatism” is an astigmatism caused on a fundus of an eye through the lens.
- When a progressive power spectacle lens is provided with a large base curve, the transmission performance is substantially coincident with the surface performance. This means that the good transmission performance lens can be designed by the surface evaluating design. However, the large curvature of the lens results in a heavy and thick lens.
- Recently, a small base curve is generally required to obtain a light and thin lens even in the field of the progressive power spectacle lens. When the progressive power spectacle lens is designed so as to have a small base curve, the transmission performance is not coincident with the surface performance. That is, the lens having the umbilical main meridian results in insufficient transmission performance.
- Japanese provisional patent publication Nos. SHO 59-58415, HEI 1-221722, HEI 8-136868 and HEI 4-500870 (the counterpart of PCT international patent publication W091/01508) disclose the progressive power spectacle lenses that have non-umbilical main meridians. Although each of the publications teaches the surface astigmatism along the main meridian, none of the publications disclose the variation of the surface astigmatism along the horizontal direction.
- It is therefore an object of the present invention to provide an improved progressive power spectacle lens, which has an enlarged clear vision zone with employing a small base curve.
- For the above object, according to the present invention, there is provided a progressive power spectacle lens, which includes:
- a distance portion having a dioptric power for distance vision;
- a near portion having a dioptric power for near vision; and
- an intermediate portion having a progressive dioptric power for vision at ranges intermediate between the distance and near portions;
- wherein a predetermined surface astigmatism is provided on a main meridian, and the surface astigmatism decreases and then increases as the distance from the main meridian increases in a horizontal direction within the near portion.
- The variation of the surface astigmatism is desirable to satisfy the condition (1) on at least one point in the range of −30<Y<−15, and further to satisfy the condition (2) on at least one point in the overlapped range of −30<Y<−15 and 3<|X−Xm|<10, when a rectangular coordinate (unit: mm) is defined by a fitting point O as an origin, a horizontal X-axis and a vertical Y-axis;
- AS(Xm, Y)>0.2, and (1)
- AS(Xm, Y)−AS(X, Y)>0.05, (2)
- where
- AS(x, y) is the surface astigmatism at the point (x, y), and
- Xm is a displacement (i.e., a distance along the X-axis) of the main meridian from the Y-axis defined by Xm=f(Y).
- Further, the maximum curvature direction θ(x, y) that is defined as an angle (unit: degree) with respect to the X-axis at the point (x, y) is desirable to satisfy the conditions (3) and (4);
- −10° <θ(Xm, Y)<10°, and (3)
- 60°<|θ(Xm±10, Y) <90°, (4)
- where the surface astigmatism at the points satisfying the conditions (3) and (4) are larger than 0.2.
- FIG. 1 is a map showing a surface astigmatism distribution on a progressive side surface of a spectacle lens according to a first embodiment;
- FIG. 2 is a graph showing a variation of the surface astigmatism of the lens shown in FIG. 1 along a horizontal line at Y=−25;
- FIG. 3 is a graph showing a variation of a maximum curvature direction of the lens shown in FIG. 1 along a horizontal line at Y=−25;
- FIG. 4 is a distribution map showing a resultant astigmatism distribution of the lens shown in FIG. 1;
- FIG. 5 is a distribution map of a surface astigmatism distribution on a progressive side surface of the spectacle lens according to a comparative example 1 that is not an embodiment;
- FIG. 6 is a graph showing a variation of the surface astigmatism of the lens shown in FIG. 5 along a horizontal line at Y=−25;
- FIG. 7 is a distribution map showing a resultant astigmatism distribution of the lens shown in FIG. 5;
- FIG. 8 is a distribution map showing a surface astigmatism distribution on a progressive side surface of the spectacle lens according to a second embodiment;
- FIG. 9 is a graph showing a variation of the surface astigmatism of the lens shown in FIG. 8 along a horizontal line at Y=−25;
- FIG. 10 is a graph showing a variation of the maximum curvature direction of the lens shown in FIG. 8 along a horizontal line at Y=−25;
- FIG. 11 is a distribution map showing a resultant astigmatism distribution of the lens shown in FIG. 8;
- FIG. 12 is a distribution map showing a surface astigmatism distribution on a progressive side surface of the spectacle lens according to a comparative example 2 that is not an embodiment;
- FIG. 13 is a graph showing a variation of the surface astigmatism of the lens shown in FIG. 12 along a horizontal line at Y=−25;
- FIG. 14 is a distribution map of a resultant astigmatism distribution of the lens shown in FIG. 12;
- FIG. 15 shows rectangular coordinates on a progressive power spectacle lens;
- FIG. 16 is a graph showing the definition of the maximum curvature direction; and
- FIG. 17 shows a general distribution of portions on the progressive side surface of a progressive power spectacle lens.
- First and second embodiments will be described hereinafter in contrast to comparative examples. The progressive power spectacle lens according to each of the embodiments includes a distance portion having a dioptric power for distance vision, a near portion having a dioptric power for near vision, and an intermediate portion having a progressive dioptric power for vision at ranges intermediate between distance and near portions.
- A main meridian is not an umbilical line. A predetermined surface astigmatism is provided on the main meridian as defined by condition (1) on at least one point in the range of −30<Y<−15 when a rectangular coordinate (unit: mm) is defined by a fitting point O as an origin, a horizontal X-axis, and a vertical Y-axis;
- AS(Xm, Y)>0.2, (1)
- where
- AS(x, y) is the surface astigmatism at the point (x, y), and
- Xm is a displacement (i.e., a distance along the X-axis) of the main meridian from the Y-axis defined by Xm=f(Y).
- FIG. 15 shows the rectangular coordinate on the progressive power spectacle lens. The range of −30<Y<−15 is indicated by “A”.
- In the near portion, the surface astigmatism decreases and then increases as the distance from the main meridian MM′ increases in a horizontal direction (i.e., in the X-axis direction) within a clear vision zone. Such a distribution of the surface astigmatism is effective to enlarge the width of the clear vision zone. The variation of the surface astigmatism satisfies condition (2) on at least one point in the overlapped range of −30<Y<−15 and 3<|X−Xm|<10;
- AS(Xm, Y)−AS(X, Y)>0.05. (2)
- In FIG. 15, the range of 3<|X−Xm|<10 is indicated by “B”. Condition (2) is satisfied in the ranges (shown by hatching) where the ranges A and B overlap. Optionally, the range B may be limited to 5<|X−Xm|<10.
- Further, the maximum curvature direction θ(x, y) that is defined as an angle (unit: degree) with respect to the X-axis at the point (x, y) satisfies conditions (3) and (4);
- −10°<|θ(Xm, Y)<10°, and (3)
- 60°<|θ(Xm±10, Y)<90°, (4)
- where the surface astigmatism at the points satisfying conditions (3) and (4) are larger than 0.2.
- The dioptric power at a point on the progressive side surface can be described as an ellipse as shown in FIG. 16. The size of the ellipse indicates the dioptric power at the point (x, y). The point having the surface astigmatism is indicated by an ellipse, while an umbilical point is indicated by a circle. A major axis Cmax of the eclipse represents the direction of the maximum curvature thereof, and the angle of the major axis Cmax with respect to the X-axis is the maximum curvature direction θ(x, y).
- Condition (3) requires that the maximum curvature direction on the main meridian MM′ is substantially parallel to the horizontal direction (X-axis), and condition (4) requires that the maximum curvature direction at the points distant from the main meridian by ±10 mm is substantially perpendicular to the horizontal direction.
- Satisfaction of the condition (3) reduces the resultant astigmatism on the main meridian MM′. When the condition (4) is satisfied, a distortion can be effectively corrected.
- [First Embodiment]
- FIG. 1 is a map of a surface astigmatism distribution on a progressive side surface of the progressive power spectacle lens according to the first embodiment. Specifications of the lens are as follows:
- Base curve: 5.00 [D]
- SPH (a dioptric power at a distance design reference point ): +2.00 [D]
- Addition power: 2.00 [D]
- As shown in FIG. 1, the near portion of the lens includes a zone C (shown by hatching) in which the surface astigmatism is larger than 0.20 [D] along the main meridian MM′. The displacement Xm is equal to 2.5 mm in a range of −40<Y<−19.
- FIGS. 2 and 3 are graphs showing a variation of the surface astigmatism AS(X, −25) and a variation of the maximum curvature direction θ(X, −25) of the lens shown in FIG. 1 respectively. As shown in FIG. 2, the surface astigmatism decreases and then increases as the distance from the main meridian MM′ increases within the clear vision zone. Further, the maximum curvature direction varies along the horizontal direction as a monotonic function as shown in FIG. 3. The first embodiment satisfies conditions (1) though (4) as follows.
- (1) AS(Xm, Y)=AS(2.5, −25)=0.33. This value is larger than 0.2 and thus the condition (1) is satisfied.
- (2) AS(Xm, Y)−AS(X, Y)=AS(2.5, −25)−AS(0, −25)>0.05 If the range B (shown in FIG. 15) is defined by 3<|X−Xm|<10, condition (2) is satisfied in a range R1 (shown in FIG. 2) of −4.5<X<−0.5 and in a range R2 of 5.5<X<7.4 under the condition of Y=−25. If the range B is defined by 5<|X−Xm|<10, condition (2) is satisfied in a range R3 of −4.5<X−2.5 under the condition of Y=−25.
- (3) θ(Xm, Y)=θ(2.5, −25)=0°. This value falls within the range of condition (3).
- (4) θ(Xm−10, Y)=θ(−7.5, −25)=69°, and θ(Xm+10, Y)=θ(12.5, −25)=−69°. These values fall within the range of the condition (4).
- Since the surface astigmatism AS(2.5, −25)=0.33, AS(−7.5, −25)=0.75 and AS(12.5, −25)=1.22, the premise of conditions (3) and (4) are satisfied.
- A distribution of the resultant astigmatism, which is obtained by the transmitting evaluation, according to the first embodiment is shown in FIG. 4. The width of the clear vision zone S, in which the resultant astigmatism is lower than 0.5, is equal to 11 mm.
- FIG. 5 shows a map of a surface astigmatism distribution on a progressive side surface of the comparative example 1. This example is described for indicating the compared effect of the first embodiment and it is not an embodiment of the invention. The lens of the example 1 has the same specification as the first embodiment in the base curve, SPH and the additional power, while the lens is designed so that the surface performance is optimized. That is, the main meridian is designed as an umbilical line.
- FIG. 6 is a graph showing a variation of the surface astigmatism AS (X, −25) of the lens shown in FIG. 5. As shown in FIG. 6, the surface astigmatism is almost equal to zero on the main meridian MM′ and it monotonically increases as the distance from the main meridian MM′ increases.
- A distribution of the resultant astigmatism according to the example 1 is shown in FIG. 7. The width of the clear vision zone s is 4 mm.
- It is understood, by comparing the first embodiment with the comparative example 1, that the distribution of the surface astigmatism of the first embodiment is effective to enlarge the clear vision zone S.
- [Second Embodiment]
- FIG. 8 is a map of a surface astigmatism distribution on a progressive side surface of the progressive power spectacle lens according to the second embodiment. Specifications of the lens are as follows:
- Base curve: 2.00 [D]
- SPH: −4.00 [D]
- Addition power: 2.00 [D]
- As shown in FIG. 8, the near portion of the lens includes a zone D (shown by hatching) in which the surface astigmatism is larger than 0.20 [D] along the main meridian MM′. The displacement Xm is equal to 2.5 mm in a range of −40<Y<−19.
- FIGS. 9 and 10 are graphs showing a variation of the surface astigmatism AS (X, −25) and a variation of the maximum curvature direction θ(X, −25) of the lens shown in FIG. 8 respectively. As shown in FIG. 9, the surface astigmatism decreases and then increases as the distance from the main meridian MM′ increases within the clear vision zone. Further, the maximum curvature direction varies along the horizontal direction as a monotonic function as shown in FIG. 10. The second embodiment satisfies the conditions (1) though (4) as follows.
- (1) AS(Xm, Y)=AS(2.5, −25)=0.26. This value is larger than 0.2 and thus the condition (1) is satisfied.
- (2) AS(Xm, Y)−AS(X, Y)=AS(2.5, −25)−AS(0, −25)>0.05 If the range B (shown in FIG. 15) is defined by 3<|X−Xm|<10, the condition (2) is satisfied in a range R4 (shown in FIG. 9) of −2.7<X<−0.5 and in a range R5 of 5.5<X<8.2 under the condition of Y=−25. If the range B is defined by 5<|X−Xm|<10, the condition (2) is satisfied in a range R6 of −2.7<X<−2.5 under the condition of Y=−25.
- (3) θ(Xm, Y)=θ(2.5, −25)−0°. This value falls within the range of the condition (3).
- (4) θ(Xm−10, Y)=θ(−7.5, −25)=67°, and θ(Xm+10, Y)=θ(12.5, −25)=−70°. These values fall within the range of the condition (4).
- Since the surface astigmatism AS(2.5, −25)=0.26, AS(−7.5, −25)=0.78 and AS(12.5, −25)=0.85, the premise of the conditions (3) and (4) are satisfied.
- A distribution of the resultant astigmatism, which is obtained by the transmitting evaluation, according to the second embodiment is shown in FIG. 11. The width of the clear vision zone s is equal to 12 mm.
- FIG. 12 shows a map of a surface astigmatism distribution on a progressive side surface of the comparative example 2. This example is not an embodiment of the invention. The lens of the example 2 has the same specification as the second embodiment in the base curve, SPH and the additional power, while the lens is designed so that the surface performance is optimized. That is, the main meridian is designed as an umbilical line.
- FIG. 13 is a graph showing a variation of the surface astigmatism AS(X, −25) of the lens shown in FIG. 12. As shown in FIG. 13, the surface astigmatism is almost equal to zero on the main meridian MM′ and it monotonically increases as the distance from the main meridian MM′ increases.
- A distribution of the resultant astigmatism according to the example 2 is shown in FIG. 14. The clear vision zone is limited at only the center portion of the lens. The width of the clear vision zone s is 7 mm.
- It is understood, by comparing the second embodiment with the comparative example 2, that the distribution of the surface astigmatism of the second embodiment is effective to enlarge the clear vision zone.
- The present disclosure relates to the subject matter contained in Japanese Patent Application No. HEI 10-068223, filed on Mar. 18, 1998, which is expressly incorporated herein by reference in its entirety.
Claims (6)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP06822398A JP3605281B2 (en) | 1998-03-18 | 1998-03-18 | Progressive multifocal lens |
JP10-068223 | 1998-03-18 | ||
JP10-68223 | 1998-03-18 |
Publications (2)
Publication Number | Publication Date |
---|---|
US20010030735A1 true US20010030735A1 (en) | 2001-10-18 |
US6354704B2 US6354704B2 (en) | 2002-03-12 |
Family
ID=13367608
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/271,454 Expired - Lifetime US6354704B2 (en) | 1998-03-18 | 1999-03-18 | Progressive power spectacle lens |
Country Status (6)
Country | Link |
---|---|
US (1) | US6354704B2 (en) |
JP (1) | JP3605281B2 (en) |
KR (1) | KR100454604B1 (en) |
DE (1) | DE19912200B4 (en) |
FR (1) | FR2776397B1 (en) |
GB (1) | GB2338081B (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2834568A1 (en) * | 2002-01-07 | 2003-07-11 | Pentax Corp | GLASSES WITH PROGRESSIVE POWER |
US6712467B1 (en) * | 1999-04-13 | 2004-03-30 | Hoya Corporation | Progressive-power lens and design process for same |
WO2005040894A1 (en) * | 2003-10-23 | 2005-05-06 | Rodenstock Gmbh | Workplace screen lens |
EP3457195A1 (en) * | 2017-09-19 | 2019-03-20 | Hoya Lens Thailand Ltd. | Spectacle lenses and methods for producing the same |
EP2678732B1 (en) * | 2011-02-23 | 2020-04-22 | EHS Lens Philippines, Inc. | Spectacle lens |
CN113906332A (en) * | 2019-09-25 | 2022-01-07 | 豪雅镜片泰国有限公司 | Progressive-power lens design method, progressive-power lens design system, and progressive-power lens group |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4164550B2 (en) | 2001-10-12 | 2008-10-15 | セイコーオプティカルプロダクツ株式会社 | Progressive power spectacle lens |
JP3882748B2 (en) * | 2002-12-12 | 2007-02-21 | セイコーエプソン株式会社 | Progressive power lens |
JP4885445B2 (en) * | 2004-12-21 | 2012-02-29 | 株式会社フジミインコーポレーテッド | Thermal spray powder |
WO2020067522A1 (en) * | 2018-09-28 | 2020-04-02 | Hoya株式会社 | Progressive power lens and design method therefor |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5958415A (en) | 1982-09-29 | 1984-04-04 | Seiko Epson Corp | Progressive multifocal lens |
SE453959B (en) * | 1986-06-04 | 1988-03-21 | Gote Palsgard | ARRANGEMENT FOR POSSIBILITY FOR DISABLED DISABLED PERSONS WITHOUT NUMBER AND MOVEMENT FORMS IN THE ARMS TO COMMUNICATE WITH THE ENVIRONMENT |
JP2756670B2 (en) | 1987-11-30 | 1998-05-25 | 旭光学工業株式会社 | Progressive multifocal spectacle lens |
JP2576054B2 (en) | 1988-02-29 | 1997-01-29 | 株式会社ニコン | Progressive multifocal lens |
WO1991001508A1 (en) | 1989-07-17 | 1991-02-07 | Optische Werke G. Rodenstock | Progressive spectacle glass with positive action in the distance portion |
US5327181A (en) | 1993-01-12 | 1994-07-05 | Gentex Optics, Inc. | Progressive lens for specialty and occupational use |
JP3381306B2 (en) * | 1993-05-31 | 2003-02-24 | 株式会社ニコン | Progressive focus lens |
US5719657A (en) | 1993-11-19 | 1998-02-17 | Asahi Kogaku Kogyo Kabushiki Kaisha | Progressive power lens |
JP3495437B2 (en) * | 1993-11-19 | 2004-02-09 | ペンタックス株式会社 | Progressive multifocal lens |
JP3619264B2 (en) | 1994-08-22 | 2005-02-09 | ペンタックス株式会社 | Progressive multifocal lens and its mold |
JP3196877B2 (en) * | 1995-04-18 | 2001-08-06 | ホーヤ株式会社 | Progressive multifocal lens |
FR2733328B1 (en) | 1995-04-21 | 1997-06-13 | Essilor Int | PROGRESSIVE MULTIFOCAL OPHTHALMIC LENS |
JP3196880B2 (en) * | 1995-09-22 | 2001-08-06 | ホーヤ株式会社 | Progressive multifocal lens |
DE59709693D1 (en) | 1996-07-05 | 2003-05-08 | Rodenstock Gmbh | PROGRESSIVE EYEWEAR |
-
1998
- 1998-03-18 JP JP06822398A patent/JP3605281B2/en not_active Expired - Fee Related
-
1999
- 1999-03-18 DE DE19912200.8A patent/DE19912200B4/en not_active Expired - Lifetime
- 1999-03-18 KR KR10-1999-0009101A patent/KR100454604B1/en not_active IP Right Cessation
- 1999-03-18 US US09/271,454 patent/US6354704B2/en not_active Expired - Lifetime
- 1999-03-18 GB GB9906289A patent/GB2338081B/en not_active Expired - Lifetime
- 1999-03-18 FR FR9903378A patent/FR2776397B1/en not_active Expired - Lifetime
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6712467B1 (en) * | 1999-04-13 | 2004-03-30 | Hoya Corporation | Progressive-power lens and design process for same |
FR2834568A1 (en) * | 2002-01-07 | 2003-07-11 | Pentax Corp | GLASSES WITH PROGRESSIVE POWER |
WO2005040894A1 (en) * | 2003-10-23 | 2005-05-06 | Rodenstock Gmbh | Workplace screen lens |
US7338162B2 (en) | 2003-10-23 | 2008-03-04 | Rodenstock Gmbh | Workplace screen lens |
EP2678732B1 (en) * | 2011-02-23 | 2020-04-22 | EHS Lens Philippines, Inc. | Spectacle lens |
EP3457195A1 (en) * | 2017-09-19 | 2019-03-20 | Hoya Lens Thailand Ltd. | Spectacle lenses and methods for producing the same |
WO2019059410A1 (en) * | 2017-09-19 | 2019-03-28 | Hoya Lens Thailand Ltd. | Spectacle lenses and methods for producing the same |
CN113906332A (en) * | 2019-09-25 | 2022-01-07 | 豪雅镜片泰国有限公司 | Progressive-power lens design method, progressive-power lens design system, and progressive-power lens group |
Also Published As
Publication number | Publication date |
---|---|
GB2338081B (en) | 2002-06-19 |
KR100454604B1 (en) | 2004-11-03 |
GB2338081A (en) | 1999-12-08 |
DE19912200B4 (en) | 2015-02-26 |
KR19990077991A (en) | 1999-10-25 |
JP3605281B2 (en) | 2004-12-22 |
US6354704B2 (en) | 2002-03-12 |
JPH11264955A (en) | 1999-09-28 |
FR2776397B1 (en) | 2000-11-10 |
GB9906289D0 (en) | 1999-05-12 |
FR2776397A1 (en) | 1999-09-24 |
DE19912200A1 (en) | 1999-09-23 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5710615A (en) | Progressive power multifocal lens | |
US7422325B2 (en) | Method of designing a spectacle lens | |
US7874673B2 (en) | Progressive power lens and method of designing the same | |
US6652097B2 (en) | Progressive-power spectacle lens | |
US6354704B2 (en) | Progressive power spectacle lens | |
JP3080295B2 (en) | Progressive multifocal spectacle lens | |
US20100045931A1 (en) | Short Channel Progressive Addition Lenses | |
EP1895351A1 (en) | Spectacle lens design method | |
US6220704B1 (en) | Progressive power lens | |
US7008058B2 (en) | Progressive spectacle lens having two aspherical progressive surfaces | |
US7125118B2 (en) | Progressive multifocal lens and method of designing the same | |
JP4024851B2 (en) | A set of progressive ophthalmic lenses | |
JP4806218B2 (en) | Progressive power lens | |
WO2013046677A1 (en) | Progressive refractive power lens | |
JP2008249828A (en) | Eyeglass lens and design method thereof | |
US7040758B2 (en) | Spectacle lens | |
US6715875B2 (en) | Astigmatic-power spectacle lens | |
JP4401175B2 (en) | Progressive power lens | |
US6736505B2 (en) | Progressive power spectacle lens | |
JP2000227579A (en) | Inner progressive refractive lens | |
US11681163B2 (en) | Pair of progressive power lenses and design method for the same | |
EP0964285A1 (en) | Aspheric ophthalmic lens | |
US20020101565A1 (en) | Multifocal lens capable of preventing distortion on edge of the lens with enlarging a nearsighted region | |
US7341344B2 (en) | Progressive power lens | |
JP2003262837A (en) | Progressive refracting power lens |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: ASAHI KOGAKU KOGYO KABUSHIKI KAISHA, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:YAMAMOTO, CHIKARA;REEL/FRAME:009991/0963 Effective date: 19990330 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
AS | Assignment |
Owner name: SEIKO OPTICAL PRODUCTS KABUSHIKI KAISHA (TRADING A Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:PENTAX CORPORATION;REEL/FRAME:021691/0025 Effective date: 20080328 |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
FPAY | Fee payment |
Year of fee payment: 12 |
|
AS | Assignment |
Owner name: HOYA LENS THAILAND LTD., THAILAND Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SEIKO OPTICAL PRODUCTS CO.,LTD.;REEL/FRAME:040741/0245 Effective date: 20161001 Owner name: SEIKO OPTICAL PRODUCTS CO.,LTD., JAPAN Free format text: CHANGE OF ADDRESS;ASSIGNOR:SEIKO OPTICAL PRODUCTS CO.,LTD.;REEL/FRAME:041174/0192 Effective date: 20110211 |