Methods for designing and making contact lenses having aberration control and contact lenses made thereby
First Claim
1. A method for constructing a soft contact lens having a prescribed power correction for focusing light on the retina of an eye, said method comprising:
- constructing an eye model including a cornea, a crystalline lens and a retina;
selecting a shape for an anterior surface of the cornea to be a conic section having an eccentricity in the range of about 0.14<
e<
0.63;
selecting a preliminary soft contact lens having a center thickness, a radius, a posterior contact lens surface and an anterior contact lens surface to provide a prescribed plus or minus correction power such that, when applied to the anterior surface of the cornea, the anterior contact lens surface defining a conic section having a shape factor in the range of 0<
E<
1 or -1<
E<
0;
performing an analysis using the preliminary soft contact lens and eye model tracing light ray paths through the contact lens/eye system;
varying the shape factor of the anterior contact lens surface when applied to the anterior surface of the cornea to achieve an contact lens/eye system wherein a trace of light ray paths is optimized for sharpest focus by minimizing a retinal spot size of the rays, the shape factor being varied within the range of 0<
E<
1 or -1<
E<
0, thereby defining an optimized anterior contact lens surface for the soft contact lens when applied to the anterior surface of the cornea;
calculating a thickness profile for the optimum contact lens using the differences in distance between the anterior surface of the cornea and the optimized anterior contact lens surface at various values of the contact lens radius from the center of the contact lens; and
determining a shape for manufacture of said soft contact lens by selecting a first surface for said soft contact lens and calculating a second surface for said soft contact lens using said first surface and said thickness profile.
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Accused Products
Abstract
A method for constructing a soft contact lens having a prescribed power correction for focusing light on the retina of an eye is described. The method provides a soft contact lens that, when in place ("flexed") on the wearer'"'"'s eye, is designed and manufactured to provide a substantially ellipsoidal anterior surface. In the method, an eye model including a cornea, a crystalline lens and a retina is constructed. Then a shape for an anterior surface of the cornea is selected to be a conic section having an eccentricity in the range of about 0.14<e<0.63. Next, a preliminary soft contact lens is selected having a center thickness, a radius, a posterior contact lens surface and an anterior contact lens surface to provide a prescribed plus or minus correction power such that, when applied to the anterior surface of the cornea, the anterior contact lens surface defining a conic section having a shape factor in the range of 0<E<1 or -1<E<0. An analysis is performed using the preliminary soft contact lens and eye model tracing light ray paths through the contact lens/eye system. The shape factor of the anterior contact lens surface when applied to the anterior surface of the cornea is varied within the range of 0<E<1 or -1<E<0 to achieve an contact lens/eye system wherein a trace of light ray paths is optimized for sharpest focus by minimizing a retinal spot size of the rays. Thus, an optimized anterior contact lens surface for the soft contact lens when applied to the anterior surface of the cornea is defined. A thickness profile is calculated for the optimum contact lens using the differences in distance between the anterior surface of the cornea and the optimized anterior contact lens surface at various values of the contact lens radius from the center of the contact lens. Contact lenses having the calculated thickness profile can be made by conventional methods. Both monofocal and multifocal lenses having optimized aberration correction can be made.
175 Citations
36 Claims
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1. A method for constructing a soft contact lens having a prescribed power correction for focusing light on the retina of an eye, said method comprising:
-
constructing an eye model including a cornea, a crystalline lens and a retina; selecting a shape for an anterior surface of the cornea to be a conic section having an eccentricity in the range of about 0.14<
e<
0.63;selecting a preliminary soft contact lens having a center thickness, a radius, a posterior contact lens surface and an anterior contact lens surface to provide a prescribed plus or minus correction power such that, when applied to the anterior surface of the cornea, the anterior contact lens surface defining a conic section having a shape factor in the range of 0<
E<
1 or -1<
E<
0;performing an analysis using the preliminary soft contact lens and eye model tracing light ray paths through the contact lens/eye system; varying the shape factor of the anterior contact lens surface when applied to the anterior surface of the cornea to achieve an contact lens/eye system wherein a trace of light ray paths is optimized for sharpest focus by minimizing a retinal spot size of the rays, the shape factor being varied within the range of 0<
E<
1 or -1<
E<
0, thereby defining an optimized anterior contact lens surface for the soft contact lens when applied to the anterior surface of the cornea;calculating a thickness profile for the optimum contact lens using the differences in distance between the anterior surface of the cornea and the optimized anterior contact lens surface at various values of the contact lens radius from the center of the contact lens; and determining a shape for manufacture of said soft contact lens by selecting a first surface for said soft contact lens and calculating a second surface for said soft contact lens using said first surface and said thickness profile. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for constructing a multi-focal soft contact lens having a center circular zone for a first prescribed vision correction and an outer zone circumscribing the center zone for a second prescribed vision correction, one of the zones having a prescribed far distance vision correction for focusing light on the retina of an eye, said method comprising:
-
constructing an eye model including a cornea, a crystalline lens and a retina; selecting a shape for an anterior surface of the cornea to be a conic section having an eccentricity in the range of about 0.14<
e<
0.63;selecting a preliminary soft contact lens having a center thickness, a radius, a posterior contact lens surface and an anterior contact lens surface to provide a prescribed distance vision correction power in one of the zones such that, when applied to the anterior surface of the cornea, the anterior contact lens surface in a region of the distance vision correction power zone defines a conic section having a shape factor in the range of 0<
E<
1 or -1<
E<
0;performing an analysis using the preliminary soft contact lens and eye model tracing light ray paths through the contact lens/eye system in zone having distance vision correction power; varying the shape factor of the anterior contact lens surface in the zone having distance vision correction power when applied to the anterior surface of the cornea to achieve an contact lens/eye system wherein a trace of light ray paths is optimized for the zone having distance vision correction power for sharpest focus by minimizing a retinal spot size of the rays, the shape factor being varied within the range of 0<
E<
1 or -1<
E<
0, thereby defining an optimized anterior contact lens surface for the zone having distance vision correction power for the soft contact lens when applied to the anterior surface of the cornea;calculating a thickness profile for the zone having distance vision correction power for the optimum contact lens using the differences in distance between the anterior surface of the cornea and the optimized anterior contact lens surface at various values of the contact lens radius from the center of the contact lens for the zone having distance vision correction power; and determining a shape for manufacture of said soft contact lens by selecting a first surface for said soft contact lens and calculating a second surface for said soft contact lens using said first surface and said thickness profile for the zone having distance vision correction power. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A soft contact lens having a prescribed power correction for focusing light on the retina of an eye and having aberration correction, said contact lens being constructed by a method including the steps of:
-
constructing an eye model including a cornea, a crystalline lens and a retina; selecting a shape for an anterior surface of the cornea to be a conic section having an eccentricity in the range of about 0.14<
e<
0.63;selecting a preliminary soft contact lens having a center thickness, a radius, a posterior contact lens surface and an anterior contact lens surface to provide a prescribed plus or minus correction power such that, when applied to the anterior surface of the cornea, the anterior contact lens surface defining a conic section having a shape factor in the range of 0<
E <
1 or -1<
E<
0;performing an analysis using the preliminary soft contact lens and eye model tracing light ray paths through the contact lens/eye system; varying the shape factor of the anterior contact lens surface when applied to the anterior surface of the cornea to achieve an contact lens/eye system wherein a trace of light ray paths is optimized for sharpest focus by minimizing a retinal spot size of the rays, the shape factor being varied within the range of 0<
E<
1 or -1<
E<
0, thereby defining an optimized anterior contact lens surface for the soft contact lens when applied to the anterior surface of the cornea; andcalculating a thickness profile for the optimum contact lens using the differences in distance between the anterior surface of the cornea and the optimized anterior contact lens surface at various values of the contact lens radius from the center of the contact lens. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A multi-focal soft contact lens having a center circular zone for a first prescribed vision correction and an outer zone circumscribing the center zone for a second prescribed vision correction, one of the zones having a prescribed distance vision correction power for focusing light on the retina of an eye and having aberration correction, said contact lens being constructed by a method including the steps of:
-
constructing an eye model including a corneal a crystalline lens and a retina; selecting a shape for an anterior surface of the cornea to be a conic section having an eccentricity in the range of about 0.14<
e<
0.63;selecting a preliminary soft contact lens having a center thickness, a radius, a posterior contact lens surface and an anterior contact lens surface to provide a bed distance vision correction power in one of the zones such that, when applied to the anterior surface of the cornea, the anterior contact lens surface in a region of the distance vision correction power zone defines a conic section having a shape factor in the range of 0<
E<
1 or -1<
E<
0;performing an analysis using the preliminary soft contact lens and eye model tracing light ray paths through the contact lens/eye system in zone having distance vision correction power; varying the shape factor of the anterior contact lens surface in the zone having distance vision correction power when applied to the anterior surface of the cornea to achieve an contact lens/eye system wherein a trace of light ray paths is optimized for the zone having distance vision correction power for sharpest focus by minimizing a retinal spot size of the rays, the shape factor being varied within the range of 0<
E<
1 or -1<
E<
0, thereby defining an optimized anterior contact lens surface for the zone having distance vision correction power for the soft contact lens when applied to the anterior surface of t h e cornea; andcalculating a thickness profile for the zone having distance vision correction power for the optimum contact lens using the differences in distance between the anterior surface of the cornea and the optimized anterior contact lens surface at various values of the contact lens radius from the center of the contact lens for the zone having distance vision correction power. - View Dependent Claims (30, 31, 32, 33, 34)
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35. A soft contact lens comprising the structural characteristics of a lens selected from the group consisting of the following contact lenses wherein the anterior surface of the contact lens has an apical radius of curvature and eccentricity defined in the table below and the posterior surface of the contact lens is a spherical surface having an apical radius of curvature of 8.6 mm:
space="preserve" listing-type="tabular">______________________________________ Apical radius Center Lens Corrective of curvature thickness No. power (D) (mm) Eccentricity (mm) ______________________________________ 1 -10 10.75 -.59 0.10 2 -8 10.25 -.51 0.10 3 -6 9.80 -.42 0.125 4 -4 9.38 -.29 0.15 5 -2 9.01 .12 0.175 6 0 8.66 .32 0.20 7 2 8.34 .41 0.225 8 4 8.05 .47 0.25 9 6 7.77 .51 0.275 10 8 7.52 .52 0.30 ______________________________________
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36. A soft contact lens comprising the structural characteristics of a lens selected from the group consisting of the following contact lenses wherein the anterior surface of the contact lens has an apical radius of curvature and eccentricity defined in the table below and the posterior surface of the contact lens is a spherical surface having an apical radius of curvature of 8.6 mm:
space="preserve" listing-type="tabular">______________________________________ Apical radius Center Lens Corrective of curvature thickness No. power (D) (mm) Eccentricity (mm) ______________________________________ 1 -10 10.73 -.56 0.10 2 -8 10.24 -.49 0.10 3 -6 9.79 -.39 0.12 4 -4 9.38 -.26 0.15 5 -2 9.00 .16 0.17 6 0 8.66 .33 0.20 7 2 8.34 .42 0.23 8 4 8.05 .47 0.25 9 6 7.78 .51 0.28 10 8 7.51 .53 0.30 ______________________________________
Specification