Multipocal contact lens and method for preparing
OwnerLeonard Seidnerinventor
Life of this patent
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Abstract
A multifocal contact lens customized for a patient includes a central portion having a concave aspherical posterior surface of a standardized eccentricity and an annular portion connected to the central portion. The central portion also has a convex anterior surface with a power curve customized to the patient. The annular portion is provided with an aspheric annular cornea-fitting posterior surface and has an outer edge with a centralized apex, whereby the annular portion may be formed at the outer edge to be entrainable by a patient's eyelid to shift the lens relative to the patient's eye to vary which portion of the power curve is used during vision. The contact lenses according to the invention may be rigid or soft (hydrogels).
Claims29
A multifocal contact lens customized for a patient, comprising:
- an annular portion with an aspheric annular cornea-fitting posterior surface having a standardized eccentricity;
- an edge bevel at an annular periphery of said annular portion;
- a central portion connected to said annular portion, said central portion having a concave aspherical posterior surface of a standardized eccentricity, said central portion also having a convex anterior surface with an aspheric power curve customized to the patient;
- and
- a transition surface connecting said cornea-fitting posterior surface and said concave aspherical posterior surface.
A multifocal contact lens customized for a patient, comprising:
- an annular portion with an aspheric annular cornea-fitting posterior surface having a standardized eccentricity;
- an edge bevel at an annular periphery of said annular portion;
- a central portion connected to said annular portion, said central portion having a concave aspherical posterior surface of a standardized eccentricity, said central portion also having a convex anterior surface with a central power curve and a lenticular power curve of different powers both customized to the patient;
- and
- a transition surface connecting said cornea-fitting posterior surface and said concave aspherical posterior surface, said transition surface having a gradual change in curvature.
A method for use in preparing a customized multifocal contact lens, comprising the steps of:
- providing a standard diagnostic contact lens having an annular portion with a concave cornea-fitting posterior surface, said diagnostic contact lens also having a central portion with a predetermined convex anterior surface and a concave aspherical posterior surface of predetermined eccentricity;
- placing said diagnostic contact lens on the cornea of a patient's eye so that said fitting surface is in substantial contact with the cornea;
- allowing said diagnostic contact lens to align itself with the cornea in an off-center position while the patient looks at an effectively distant object;
- upon aligning of said diagnostic contact lens in said off-center position, disposing a series of test lenses before the patient's eye to determine a first portion of a power curve with which said anterior surface of said central portion could be formed to provide optimal far vision for the patient;
- and
- while the patient looks at an effectively near object, disposing another series of test lenses before the patient's eye to determine whether said anterior surface of said central portion should be formed with a second portion of a power curve to provide optimal near vision for the patient.
A multifocal contact lens customized for a patient, comprising:
- an annular portion with an aspheric annular cornea-fitting posterior surface having a standardized eccentricity between about 0.4 and about 0.8;
- an edge bevel at an annular periphery of said annular portion;
- a central portion connected to said annular portion, said central portion having a concave aspherical posterior surface of a standardized eccentricity between 0.6 and 1.50, said central portion also having a convex anterior surface with a power curve customized to the patient;
- and
- a transition surface connecting said cornea-fitting posterior surface and said concave aspherical posterior surface.
A multifocal contact lens customized for a patient, comprising:
- a central portion having a concave aspherical posterior surface of a standardized eccentricity, said central portion also having a convex anterior surface with a power curve customized to the patient;
- and
- an annular portion connected to said central portion, said annular portion being provided with an aspheric annular cornea-fitting posterior surface, said annular portion having an outer edge formed so as to be effectively entrainable by a patient's eyelid to shift the lens relative to the patient's eye to vary which portion of said power curve is used during vision.
A multifocal contact lens customized for a patient, having an annular cornea fitting posterior surface and a concave aspheric posterior surface with a standardized eccentricity, a convex anterior surface with a power curve customized to the patient, and a transition surface connecting said cornea-fitting posterior surface and said concave aspherical posterior surface.
Dependencies are inferred from the claim text.