Tear shaping for refractive correction
A lens for refractive tear shaping, including a curved lens body defining an anterior partial thickness cavity indented into its anterior surface. The anterior partial thickness cavity has an anterior facing tear shaping surface structured to form a tear lens within the anterior partial thickness cavity. The anterior partial thickness cavity is structured to define a tear lens within the anterior partial thickness cavity by interaction between a tear film of the eye and the anterior facing base tear shaping surface. The posterior curvature of the tear lens is dependent on the shape of the anterior facing base tear shaping surface.
1. A method of making a lens for refractive tear shaping, the method comprising:
determining a refractive correction for the lens;
determining a size and a shape of an anterior partial thickness cavity to be formed in the lens, based on the determined refractive correction;
forming a curved lens body from an optically transparent material, the curved lens body having a peripheral edge, wherein a thickness of the lens body from the base surface to a posterior surface of the lens body is in a range of 10 μm to 100 μm;
forming the anterior partial thickness cavity in an anterior surface of the lens body, wherein the anterior partial thickness cavity comprises:
an anterior facing base surface; and
an edge, wherein the anterior facing base surface and the edge are sized and shaped to form a tear lens within the anterior partial thickness cavity to provide the determined refractive correction.
2. The method of claim 1 , wherein forming the anterior partial thickness cavity comprises forming the base surface to have a curvature greater than that of a posterior surface of the lens body.
3. The method of claim 1 , wherein forming the anterior partial thickness cavity comprises forming the base surface to have a curvature less than that of a posterior surface of the lens body.
4. The method of claim 1 , wherein forming the anterior partial thickness cavity comprises forming the base surface to have a diffractive surface.
5. The method of claim 4 , wherein the diffractive surface is defined by
rn =2 nfλ
wherein rn represents a radius of curvature of the diffractive surface, n represents a refractive index or a refractive index difference, if the diffractive surface is immersed in a fluid having a refractive index other than air, f represents a focal length and λ is a wavelength of light.
6. The method of claim 4 , wherein forming the anterior partial thickness cavity comprises forming the base surface to have a shape selected from the group consisting of a convex and concave.
7. The method of claim 1 , wherein forming the anterior partial thickness cavity comprises positioning the anterior partial thickness cavity at an optical center of the lens body.
8. A method of making a lens for refractive tear shaping, the method comprising:
determining a refractive correction for the lens;
determining a size and a shape of an anterior partial thickness cavity to be formed in the lens, based on the determined refractive correction;
forming a curved lens body from an optically transparent material, the curved lens body having a peripheral edge;
forming the anterior partial thickness cavity in an anterior surface of the lens body, wherein the anterior partial thickness cavity comprises:
an anterior facing base surface; and
an edge, wherein the anterior facing base surface and the edge are sized and shaped to form a tear lens within the anterior partial thickness cavity to provide the determined refractive correction, and wherein forming the anterior partial thickness cavity comprises forming the base surface to have a diffractive surface.
9. The method of claim 8 , wherein forming the anterior partial thickness cavity further comprises forming the base surface to have a curvature greater than that of a posterior surface of the lens body.
10. The method of claim 8 , wherein forming the anterior partial thickness cavity further comprises forming the base surface to have a curvature less than that of a posterior surface of the lens body.
11. The method of claim 8 , wherein forming the anterior partial thickness cavity further comprises positioning the anterior partial thickness cavity at an optical center of the lens body.
12. The method of claim 8 , wherein a thickness of the lens body from the base surface to a posterior surface of the lens body is in a range of 10 μm to 100 μm.
13. The method of claim 8 , wherein the diffractive surface is defined by
rn =2 nfλ
wherein rn represents a radius of curvature of the diffractive surface, n represents a refractive index or a refractive index difference, if the diffractive surface is immersed in a fluid having a refractive index other than air, f represents a focal length and λ is a wavelength of light.
14. The method of claim 8 , wherein forming the anterior partial thickness cavity further comprises forming the base surface to have a shape selected from the group consisting of a convex and concave.
15. A method of making a lens for refractive tear shaping, the method comprising:
determining a refractive correction for the lens;
determining a size and a shape of an anterior partial thickness cavity to be formed in the lens, based on the determined refractive correction;
forming a curved lens body from an optically transparent material, the curved lens body having a peripheral edge;
forming the anterior partial thickness cavity in an anterior surface of the lens body, wherein the anterior partial thickness cavity comprises:
an anterior facing base surface; and
an edge, wherein the anterior facing base surface and the edge are sized and shaped to form a tear lens within the anterior partial thickness cavity to provide the determined refractive correction, and wherein forming the anterior partial thickness cavity comprises forming the base surface to have a curvature greater than that of a posterior surface of the lens body.
16. The method of claim 15 , wherein forming the anterior partial thickness cavity further comprises forming the base surface to have a diffractive surface.
17. The method of claim 16 , wherein the diffractive surface is defined by
rn =2 nfλ
wherein rn represents a radius of curvature of the diffractive surface, n represents a refractive index or a refractive index difference, if the diffractive surface is immersed in a fluid having a refractive index other than air, f represents a focal length and λ is a wavelength of light.
18. The method of claim 16 , wherein forming the anterior partial thickness cavity further comprises forming the base surface to have a shape selected from the group consisting of a convex and concave.
19. The method of claim 15 , wherein forming the anterior partial thickness cavity further comprises positioning the anterior partial thickness cavity at an optical center of the lens body.
20. The method of claim 15 , wherein a thickness of the lens body from the base surface to a posterior surface of the lens body is in a range of 10 μm to 100 μm.