Progressive addition spectacle lens

Claim 2

A progressive power ophthalmic lens comprising: a lens body with a progressive power surface having a first vision portion and a second vision portion, the power of one of said portions being different than the other; at least one of said first and second vision portions being a point surrounded by an area of optical stability in which the power changes gradually but imperceptively across said area toward said point; an intermediate portion of gradually changing power between said point of said one vision portion and the other of said vision portions; the form of the progressive surface of said lens being effective to distribute surface astigmatism over substantially the entire surface of the lens from said point of said one vision portion to the other vision portion.

Claim 3

A progressive power ophthalmic lens as in claim 1 wherein: said contours of successively different means surface powers converge toward said point.

Claim 4

A progressive power ophthalmic lens as in claim 1 wherein: the surface astigmatism is distributed substantially uniformly over the entire surface of the lens.

Claim 5

A progressive power ophthalmic lens as in claim 1 wherein: said area of optical stability around said point is effectively spherical.

Claim 6

A progressive power ophthalmic lens as in claim 1 wherein the power progression along meridian from said point to said other portion is smooth.

Claim 7

A progressive power lens according to claim 5 wherein the mean square gradient of the progression or one of its higher derivatives is a minimum.

Claim 8

A progressive power ophthalmic lens as in claim 1 wherein: each of said first vision and second vision portions is a point, each of said points being surrounded by an area of optical stability and having a series of contours of successively different constant mean surface powers around the point, said points forming the poles of a bipolar system of coordinate line approximately coincident with isopower contours on the progressive power surface of the lens.

Claim 9

A progressive power lens according to claim 7 wherein the progressive power surface comprises the curve of intersection of a sequence of spheres of varying radii and a corresponding sequence of cylinders of varying diameters.

Claim 10

A progressive power ophthalmic lens comprising: a lens body have a progressive power surface with a reading portion of a first effectively constant power, a distance portion of a second effectively constant power, and an intermediate portion of gradually changing power between the reading portion and the distance portion; at least one of said distance and reading portions being defined by an area of optical stability in which the power changes gradually but visually imperceptively around the toward a point; the form of the progressive power surface of the lens being effective to distribute surface astigmatism over substantially the entire surface of the lens from said point of said one portion to the other portion.

Claim 11

A progressive power ophthalmic lens comprising: a lens body have a progressive power surface with a reading portion of a first effectively constant power, a distance portion of a second effectively constant power, and an intermediate portion of gradually changing power between the reading portion and the distance portion; at least one of said distance and reading portions being defined by an area of optical stability in which the power changes gradually but visually imperceptively around the toward a point; the form of the progressive power surface of the lens being effective to distribute surface astigmatism over substantially the entire surface of the lens from said point of said one portion to the other portion.

Claim 12

A progressive power ophthalmic lens as in claim 9 wherein: the surface astigmatism is distributed substantially uniformly over the entire surface of the lens.

Claim 13

A progressive power ophthalmic lens as in claim 9 wherein: said area of optical stability around said point is effectively spherical.

Claim 14

A progressive power ophthalmic lens as in claim 9 wherein the power progression along a meridian from said point to said other portion is smooth.

Claim 15

A progressive power lens according to claim 12 wherein the mean square gradient of the progression or one of its higher derivatives is a minimum.

Claim 16

A progressive power ophthalmic lens as in claim 9 wherein: each of said reading and distance portions is a point, each of said points being surrounded by an area of optical stability and having a series of contours of successively different constant mean surface powers around the point, said points forming the poles of a bipolar system of coordinate lines approximately coincident with isopower contours on the progressive power surface of the lens.

Claim 17

A progressive power lens according to claim 14 wherein the progressive power surface comprises the curve of intersection of a sequence of spheres of varying radii and a corresponding sequence of cylinders of varying diameters.

Claim 18

A progressive power ophthalmic lens comprising: a body having a progressive power surface with a reading portion and a distance portion, the reading portion being of higher power than the distance portion; a progression of contours of constant means surface power extending from the distance portion to the reading portion and increasing in power along the meridian from the distance portion to the reading portion; at least one of said distance and reading portions being defined by an area of optical stability wherein successive contours of constant mean surface power converge toward a point; and the form of the progressive power surface of the lens being effective to distribute surface astigmatism over substantially the entire surface of the lens from said point of said one portion to the other portion.

Claim 19

A progressive power ophthalmic lens comprising: a body having a progressive power surface with a reading portion and a distance portion, the reading portion being of higher power than the distance portion; a progression of contours of constant means surface power extending from the distance portion to the reading portion and increasing in power along the meridian from the distance portion to the reading portion; at least one of said distance and reading portions being defined by an area of optical stability wherein successive contours of constant mean surface power converge toward a point; and the form of the progressive power surface of the lens being effective to distribute surface astigmatism over substantially the entire surface of the lens from said point of said one portion to the other portion.

Claim 20

A progressivepower ophthalmic lens as in claim 16 wherein: the surface astigmatism is distributed substantially uniformly over the entire surface of the lens.

Claim 21

A progressively power ophthalmic lens as in claim 16 wherein: said area of optical stability around said point is effectively spherical.

Claim 22

A progressive power lens according to claim 16 wherein the power progression along the meridian is smooth.

Claim 23

A progressive power lens according to claim 19 wherein the mean square gradient of the progression or one of its higher derivatives is a minimum.

Claim 24

A progressive power ophthalmic lens as in claim 16 wherein: each of said reading and distance portions is a point, each of said points being surrounded by an area of optical stability and having a series of contours of successively different constant mean surface powers around the point, said points forming the poles of a bipolar system of coordinate lines approximately coincident with isopower contours on the progressive power surface of the lens.

Claim 25

A progressive power lens according to claim 21 wherein the progressive power surface comprises the curve of intersection of a sequence of spheres of varying radii and a corresponding sequence of cylinders of varying diameters.

Claim 26

A progressive power ophthalmic lens comprising a lens body having a progressive power surface with a reading portion and a distance portion, the reading portion having a higher power than the distance portion, at least one of said reading and distance portions being defined by an area of optical stability having a series of contours of successively different constant mean surface powers around a point, the power change in said area of optical stability being imperceptible, a meridian of continuous change of power between said distance portion and said reading portion, and the form of the progressive power surface of the lens being effective to distribute surface astigmatism over substantially the entire surface of the lens from the distance portion to the reading portion.

Claim 27

A progressive power ophthalmic lens comprising a lens body having a progressive power surface with a reading portion and a distance portion, the reading portion having a higher power than the distance portion, at least one of said reading and distance portions being defined by an area of optical stability having a series of contours of successively different constant mean surface powers around a point, the power change in said area of optical stability being imperceptible, a meridian of continuous change of power between said distance portion and said reading portion, and the form of the progressive power surface of the lens being effective to distribute surface astigmatism over substantially the entire surface of the lens from the distance portion to the reading portion.

Claim 28

A progressive power ophthalmic lens as in claim 23 wherein: said contours of successively different mean surface powers converge toward said point.

Claim 29

A progressive power ophthalmic lens as in claim 23 wherein: the surface astigmatism is distributed substantially uniformly over the entire surface of the lens.

Claim 30

A progressive power ophthalmic lens as in claim 23 wherein: said area of optical stability around said point is effectively spherical.

Claim 31

A progressive power lens according to claim 23 wherein the power progression along the meridian is smooth.

Claim 32

A progressive power lens according to claim 27 wherein the mean square gradient of the progression or one of its higher derivatives is a minimum.

Claim 33

A progressive power ophthalmic lens as in claim 23 wherein: each of said reading and distance portions is a point, each of said points being surrounded by an area of optical stability and having a series of contours of successively different constant mean surface powers around the point, said points forming the poles of a bipolar system of coordinate lines approximately coincident with isopower contours on the progressive power surface of the lens.

Claim 34

A progressive power lens according to claim 23 wherein the progressive power surface comprises the curve of intersection of a sequence of spheres of varying radii and a corresponding sequence of cylinders of varying diameters.

Claim 35

A progressive ophthalmic power lens comprising a lens body having a progressive power surface with a reading portion of relatively high power and a distance portion of relatively lower power, wherein constant power regions of the reading portion and the distance portion comprise substantially tow spaced points on the progressive power surface of the lens, each of said points being surrounded by an area of optical stability and an area of progressive power, said two spaced points being connected by an umbilic of progressive dioptric power, and the surface being shaped to distribute surface astigmatism over essentially the surface of the lens between said two spaced points.

Claim 36

A progressive ophthalmic power lens comprising a lens body having a progressive power surface with a reading portion of relatively high power and a distance portion of relatively lower power, wherein constant power regions of the reading portion and the distance portion comprise substantially tow spaced points on the progressive power surface of the lens, each of said points being surrounded by an area of optical stability and an area of progressive power, said two spaced points being connected by an umbilic of progressive dioptric power, and the surface being shaped to distribute surface astigmatism over essentially the surface of the lens between said two spaced points.

Claim 37

A progressive power lens according to claim 31 wherein said areas of optical stability around said two spaced points are effectively spherical.

Claim 38

A progressive power lens according to claim 31 wherein the power progression along the umbilic line is smooth.

Claim 39

A progressive power lens according to claim 33 wherein the mean square gradient of the progression or one of its higher derivatives is a minimum.

Claim 40

A progressive power lens according to claim 31 wherein the spaced points are the poles of a bipolar system of coordinate lines approximately coincident with isopower contours on the progressive power surface of the lens.

Claim 41

A progressive power lens according to claim 31, wherein the progressive power surface comprises the curve of intersection of a sequence of spheres of varying radii and a corresponding sequence of circular cylinders of varying diameters.

Claim 42

In a progressive power ophthalmic lens having two refractive surfaces one of which is divided into three viewing zones comprising an upper distance portion, an intermediate progressive portion and a lower near portion, and having a principal vertical meridian defined by a sequence of points traversing said zones, wherein said distance portion is in the upper portion of said lens and provides a focal length for distant vision, wherein said near portion is in a lower portion of said lens and provides a focal length for near vision, and wherein said intermediate progressive portion lies between said distance and near portions and has a varying curvature which increases continuously and progressively along said meridian from a minimum value, which approximates the curvature of said distance portion, to a maximum value, which approximates the curvature of said near portion, the improvement wherein said distance portion and said reading portion each comprise substantially a point surrounded by an area of essentially indiscernible power change and a area of progressive power, and wherein the surface of the progressive portion comprises the curve of intersection of a sequence of spheres of varying radii and a corresponding sequence of cylinders of varying diameters, the surface astigmatism being distributed over substantially said entire surface of the lens between said two spaced points.

Claim 43

In a progressive power ophthalmic lens having two refractive surfaces one of which is divided into three viewing zones comprising an upper distance portion, an intermediate progressive portion and a lower near portion, and having a principal vertical meridian defined by a sequence of points traversing said zones, wherein said distance portion is in the upper portion of said lens and provides a focal length for distant vision, wherein said near portion is in a lower portion of said lens and provides a focal length for near vision, and wherein said intermediate progressive portion lies between said distance and near portions and has a varying curvature which increases continuously and progressively along said meridian from a minimum value, which approximates the curvature of said distance portion, to a maximum value, which approximates the curvature of said near portion, the improvement wherein said distance portion and said reading portion each comprise substantially a point surrounded by an area of essentially indiscernible power change and a area of progressive power, and wherein the surface of the progressive portion comprises the curve of intersection of a sequence of spheres of varying radii and a corresponding sequence of cylinders of varying diameters, the surface astigmatism being distributed over substantially said entire surface of the lens between said two spaced points.

Claim 44

A progressive power lens comprising a lens body having a progressive power surface defined by the equation ##EQU17## h=distance between DP and RP poles, L=distance of DP pole above origin O, r D =radius of curvature of the progressive surface at the DP pole, r R =radius of curvature of the progressive surface at the RP pole, c n =constant coefficients, and N=order of polynomial power law.

Claim 45

A progressive power lens comprising a lens body having a progressive power surface defined by the equation ##EQU17## h=distance between DP and RP poles, L=distance of DP pole above origin O, r D =radius of curvature of the progressive surface at the DP pole, r R =radius of curvature of the progressive surface at the RP pole, c n =constant coefficients, and N=order of polynomial power law.