Contact lenses with off-center sphere surface
AssigneeNovartis AG
InventorsMing Ye, Curtis Dean McKenney
Life of this patent
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Abstract
The present invention provides a contact lens comprising a convex surface and a concave surface, one or both of the surfaces comprising: a) a central optical zone that is an aspherical sub-surface; b) a transition zone that is adjacent to said central optical zone, wherein and is a rotationally symmetric off-center sphere sub-surface; and c) a peripheral zone that comprises one or more sphere sub-surfaces, wherein all sub-surfaces are tangent to each other. By having a transition zone of the present invention, flexion points at the junction of optical zone with peripheral zone can be eliminated. The present invention also provides a method for producing a contact lens of the present invention.
Claims17
A contact lens comprising a convex surface and a concave surface, one or both of the surfaces comprising:
- (a) an apex;
- (b) an axis passing through the apex;
- (c) a central optical zone that is an aspherical sub-surface described by an aspherical function form yopz(x);
- (d) a transition zone that is adjacent to and surrounds said central optical zone, wherein said transition zone is a rotationally symmetric off-center sphere sub-surface characterized by having a curvature radius ra the center C(xc,yc) of which is not located in the axis, wherein said curvature radius (ra) is defined by a functional form (2)
- r
- a
- =
- {
- 1
- +
- [
- y
- opz
- ′
-
- (
- x
- a
- )
- ]
- 2
- }
- 3
- /
- 2
- y
- opz
- ′′
-
- (
- x
- a
- )
- ,
- (
- 2
- )
- wherein the center C(xc,yc) of the curvature radius ra is given by formula (3) and (4)
- x
- c
- =
- x
- a
- -
- y
- opz
- ′
-
- (
- x
- a
- )
- ·
- {
- 1
- +
- [
- y
- opz
- ′
-
- (
- x
- a
- )
- ]
- 2
- }
- y
- opz
- ′′
-
- (
- x
- a
- )
- (
- 3
- )
- y
- c
- =
- y
- a
- -
- {
- 1
- +
- [
- y
- opz
- ′
-
- (
- x
- a
- )
- ]
- 2
- }
- y
- opz
- ′′
-
- (
- x
- a
- )
- (
- 4
- )
- wherein y′opz(Xa) is the 1st derivative of the aspherical function form at a junction point A(xa,ya) of the transition zone with the central optical zone, y″opz(xa) is the 2nd derivative of the aspherical function form at the junction point A(xa,ya);
- and
- (e) a peripheral zone that comprises one or more sphere sub-surfaces, wherein all sub-surfaces are tangent to each other.
A method of producing a contact lens, comprising the steps of providing a convex surface and a concave surface, one or both of the surfaces comprising:
- (a) an apex;
- (b) an axis passing through the apex;
- (c) a central optical zone that is an aspherical sub-surface described by an aspherical function form form yopz(x);
- (d) a transition zone that is adjacent to and surrounds said central optical zone, wherein said transition zone is a rotationally symmetric off-center sphere sub-surface characterized by having a curvature radius ra, the center C(xc,yc) of which is not located in the axis, wherein said curvature radius (ra) is defined by a functional form (2)
- r
- a
- =
- {
- 1
- +
- [
- y
- opz
- ′
-
- (
- x
- a
- )
- ]
- 2
- }
- 3
- /
- 2
- y
- opz
- ′′
-
- (
- x
- a
- )
- ,
- (
- 2
- )
- wherein the center C(xc,yc) of the curvature radius ra is given by formula (3) and (4)
- x
- c
- =
- x
- a
- -
- y
- opz
- ′
-
- (
- x
- a
- )
- ·
- {
- 1
- +
- [
- y
- opz
- ′
-
- (
- x
- a
- )
- ]
- 2
- }
- y
- opz
- ′′
-
- (
- x
- a
- )
- (
- 3
- )
- y
- c
- =
- y
- a
- +
- {
- 1
- +
- [
- y
- opz
- ′
-
- (
- x
- a
- )
- ]
- 2
- }
- y
- opz
- ′′
-
- (
- x
- a
- )
- (
- 4
- )
- wherein y′opz(xa) is the 1st derivative of the aspherical function form at a junction point A(xa,ya) of the transition zone with the central optical zone, y″opz(xa) is the 2nd derivative of the aspherical function form at the junction point A(xa,ya);
- and
- (e) a peripheral zone that comprises one or more sphere sub-surfaces, wherein all sub-surfaces are tangent to each other.
A series of contact lenses comprising contact lenses having different power corrections, wherein each contact lens in the series comprises a convex surface and a concave surface, one or both of the surfaces comprising:
- (a) an apex;
- (b) an axis passing through the apex;
- (c) a central optical zone that is an aspherical sub-surface described by an aspherical function form form yopz(x);
- (d) a transition zone that is adjacent to and surrounds said central optical zone, wherein said transition zone is a rotationally symmetric off-center sphere sub-surface characterized by having a curvature radius ra the center C(xc,yc) of which is not located in the axis, wherein said curvature radius (ra) is defined by a functional form (2)
- r
- a
- =
- {
- 1
- +
- [
- y
- opz
- ′
-
- (
- x
- a
- )
- ]
- 2
- }
- 3
- /
- 2
- y
- opz
- ′′
-
- (
- x
- a
- )
- ,
- (
- 2
- )
- wherein the center C(xc,yc) of the curvature radius ra is given by formula (3) and (4)
- x
- c
- =
- x
- a
- -
- y
- opz
- ′
-
- (
- x
- a
- )
- ·
- {
- 1
- +
- [
- y
- opz
- ′
-
- (
- x
- a
- )
- ]
- 2
- }
- y
- opz
- ′′
-
- (
- x
- a
- )
- (
- 3
- )
- y
- c
- =
- y
- a
- +
- {
- 1
- +
- [
- y
- opz
- ′
-
- (
- x
- a
- )
- ]
- 2
- }
- y
- opz
- ′′
-
- (
- x
- a
- )
- (
- 4
- )
- wherein y′opz(xa) is the 1st derivative of the aspherical function form at a junction point A(xa,ya) of the transition zone with the central optical zone, y″opz(xa) is the 2nd derivative of the aspherical function form at the junction point A(xa,ya);
- and
- (e) a peripheral zone that comprises one or more sphere sub-surfaces, wherein all sub-surfaces are tangent to each other.
Dependencies are inferred from the claim text.