Aspherical multifocal intraocular lens
View Patent ↗A multifocal intraocular lens has an anterior lens surface which includes a first optic of a first radius and a second optic of a different radius. The posterior surface of the lens include an aspheric surface.
1. A multifocal lens comprising:
a posterior lens surface having a first radius of curvature
an anterior aspheric lens surface, said anterior aspheric lens surface having a first aspheric distance optic portion having a radius of curvature equal to the first radius of curvature of the posterior lens surface and
a second near optic portion having a radius of curvature less than that of the first portion thereby forming a second optic surface on the anterior lens surface, the second near optic portion having an outer perimeter, and
a flat surface extending outwardly from the entire radially outer perimeter of the anterior lens near optic portion.
2. A multifocal lens as claimed in claim 1 wherein the flat surface lies in a plane which is parallel to a longitudinal axis of the lens.
3. A multifocal lens as claimed in claim 1 wherein the distance optic portion on the anterior surface is about 50% to 70% of the anterior surface of the lens and the near optic portion is about 50% to 30% of the anterior surface of the lens.
4. The multifocal lens of claim 1 wherein the distance optic portion on the anterior surface is about 60% of the anterior surface and the second near optic portion on the anterior surface is about 40% of the anterior surface.
5. The multifocal lens according to claim 1 wherein the posterior lens surface, the anterior aspherical distance optic portion and the second near optic portion of the anterior aspheric surface each consists of a convex lens surface only.
6. A method of improving the eyesight of a human comprising:
a) making an incision in an eye of the human;
b) removing a natural lens of the eye; and
c) implanting an intraocular lens, wherein the intraocular lens comprises:
d) a posterior surface, wherein the posterior surface has a radius of curvature and
e) an anterior aspheric lens surface, said anterior aspheric lens surface having a first aspheric distance optic portion having a radius of curvature equal to the radius of curvature of the posterior surface,
f) a second near optic portion having a radius of curvature less than that of the first aspheric distance optic portion thereby forming a second optic surface on the anterior lens surface,
g) the second near optic portion having an outer perimeter, and
h) a flat surface extending outwardly from the entire outer perimeter of the anterior lens near optic portion.
7. The method of claim 6 , wherein the posterior surface is aspherical in shape.
8. The method of claim 6 , wherein the intraocular lens is made from an acrylic.