Aspheric contact lens

Claim 2

A contact lens made of transparent homogeneous optical material and of a diameter between 7 and 14 mm to fit the human eye, having at least one of its surfaces a novel aspheric surface of revolution with an apical unbilical point at which the derivative of curvature vanishes and wherein said surface decreases continuously and regularly in curvature along a meridian from its apex to its peripheral edge and wherein said surface varies continuously and regularly in eccentricity from its apex to its periphery.

Claim 3

A contact lens as in claim 1, wherein the novel surface is defined by three parameters; the apical radius of curvature, r apex ; the apical eccentricity, e apex ; and collectively one or more derivatives of eccentricity.

Claim 4

A contact lens as in claim 1, wherein the instantaneous eccentricity of the novel surface at any given point on the surface is a function of the apical eccentricity of said novel surface and the derivatives of eccentricity in the form of a polynomial series in e: e.sub.x =df/dx+(d.sup.2 f/dx.sup.2)x+(d.sup.3 f/dx.sup.3)x.sup.2 +d.sup.4 f/dx.sup.4)x.sup.3 . . . , where e x is the instantaneous eccentricity at the given level x and the eccentricity of the coaxial osculating conicoid of revolution which osculates the novel surface at the level x; where df/dx at the apex of the novel surface is the apical eccentricity and the eccentricity of the coaxial osculating conicoid of revolution which osculates the novel surface at its apex; where the focal radius f of said novel surface to said given point at said level x is that of the coaxial osculating conicoid of revolution which osculates the novel surface at said given point at said level x; and where d 2 f/dx 2 , d 3 f/dx 3 , and d 4 f/dx 4 are the first, second and third derivatives of df/dx respectively.

Claim 5

A contact lens as in claim 1, wherein the novel surface is the posterior surface of the lens.

Claim 6

A contact lens as in claim 1, wherein the novel aspheric surface is the anterior surface of the lens.

Claim 7

A contact lens as in claim 1, wherein the novel surface is both anterior and posterior surfaces of the lens.

Claim 8

A contact lens as a claim 1, wherein the novel surface is the posterior surface of the lens and a spherical surface is the anterior surface of the lens.

Claim 9

A contact lens as in claim 1, wherein the novel surface is the posterior surface of the lens and a toric surface is the anterior surface of the lens.

Claim 10

A contact lens as in claim 1, wherein the novel surface is the posterior surface of the lens and a conicoid of revolution which decreases in curvature from its apex to its periphery is the anterior surface of the lens.

Claim 11

A contact lens as in claim 1, wherein the novel surface is the posterior surface of the lens and a conicoid of revolution which increases in curvature from its apex to its periphery is the anterior surface.

Claim 12

A contact lens as in claim 1, wherein the novel surface is the posterior surface of the lens and the anterior surface is a general ellipsoid having two elliptical principal meridian sections, each of which decreases in curvature from its apex to its periphery.

Claim 13

A contact lens as in claim 1, wherein the novel surface is the posterior surface of the lens and the anterior surface is a general ellipsoid having two elliptical principal meridian sections, each of which increases in curvature from its apex to its periphery.

Claim 14

A contact lens as in claim 1, wherein the novel surface is the posterior surface of the lens and the anterior surface is a general ellipsoid having two elliptical principal meridian sections, one of said principal meridian sections increasing in curvature from its apex to its periphery and the other of said principal meridian sections decreasing in curvature from its apex to its periphery.

Claim 15

A contact lens as in claim 1, wherein the novel surface is the anterior surface of the lens and a spherical surface is the posterior surface of the lens.

Claim 16

A contact lens as in claim 1, wherein the novel surface is the anterior surface of the lens and a toric surface is the posterior surface of the lens.

Claim 17

A contact lens as in claim 1, wherein the novel surface in the anterior surface of the lens and a conicoid of revolution which decreases in curvature from its apex to its periphery is the posterior surface of the lens.

Claim 18

A contact lens as in claim 1, wherein the novel surface is the anterior surface of the lens and the posterior surface is a general ellipsoid having two elliptical principal meridian sections, each of which decreases in curvature from its apex to its peripheral edge.

Claim 19

A contact lens as in claim 1, wherein the novel surface has an increasing eccentricity from its apex to its periphery.

Claim 20

A contact lens as in claim 1, wherein the novel surface has a decreasing eccentricity from its apex to its periphery.

Claim 21

A contact lens as in claim 1, wherein the novel surface is concave with the apical eccentricity ranging from 0.0 to 2.5 eccentricity units with the apical radius of curvature ranging from 6.0 to 9.2 mm and with the change in eccentricity from the apex of the novel surface to its periphery lying within the range from +2.0 to -2.0 eccentricity units.

Claim 22

A contact lens as in claim 1, wherein the novel surface is convex with the apical eccentricity ranging from 0.0 to 2.5 eccentricity units with the apical radius of curvature ranging from 4.5 to 15.0 mm and with the change in eccentricity from the apex of the novel surface to its periphery lying within the range from +2.0 to -2.0 eccentricity units.

Claim 23

A semi-finished contact lens made of transparent homogeneous optical material and of a diameter between 7 and 14 mm and of a minimum thickness of 1.5 mm, with the novel aspheric surface of revolution of the lens of this invention being the finished surface which has an apical umbilical point at which the derivative of curvature vanishes and wherein said surface decreases continuously and regularly in curvature along a meridian from its apex to its peripheral edge and wherein said surface varies continuously and regularly in eccentricity from its apex to its periphery, with the second surface being substantially plane.

Claim 24

A semi-finished contact lens made of transparent homogeneous optical material and of a diameter between 7 and 14 mm and of a minimum thickness of 1.5 mm, with the novel aspheric surface of revolution of the lens of this invention being the finished surface which has an apical umbilical point at which the derivative of curvature vanishes and wherein said surface decreases continuously and regularly in curvature along a meridian from its apex to its peripheral edge and wherein said surface varies continuously and regularly in eccentricity from its apex to its periphery, with the second surface being substantially plane.

Claim 25

A semi-finished contact lens as in claim 22, wherein the posterior concave surface is finished and is the novel surface.

Claim 26

A semi-finished contact lens as in claim 22, wherein the anterior convex surface is finished and is the novel surface.