Contact lens with meridional sagittal variation and methods for making and using the same
AssigneeCRT Technology, Inc.
InventorsJerome A. Legerton, William E. Meyers
Life of this patent
Estimating the term…
Abstract
The present invention is directed toward the design of lenses to incorporate elevation features in at least one annular zone on the posterior surface of the lens that engage the elevation differences of the eye while allowing the central zone of the lens to have conventional spherical, aspheric, multifocal or toric geometry. In various embodiments, lenses according to the present invention are rotationally stable, free of flexure and well centered over the pupil.
Claims19
A contact lens comprising:
- a central zone, an annular zone, and an edge reconciliation zone,
- wherein the annular zone comprises:
- a first point located on the posterior surface of the lens at a chord diameter along a first meridian having a first sagittal depth, and
- a second point located on the posterior surface of the lens at said chord diameter along a second meridian having a second sagittal depth,
- wherein said second sagittal depth differs from said first sagittal depth;
- and
- wherein a perimeter of the lens lies within a single plane and is circular.
A contact lens, comprised of at least one annular zone having a sagittal elevation difference between at least two points located the same radial distance from the center axis of the lens, wherein a perimeter of the lens lies within a single plane and is circular.
A contact lens comprising:
- a central zone, an annular zone, and an edge reconciliation zone,
- wherein the annular zone comprises:
- a first semi-meridian and a second semi-meridian, wherein a first radial transition of the first semi-meridian differs from a second radial transition of the second semi-meridian;
- and
- wherein a perimeter of the lens lies within a single plane and is circular.
A contact lens comprising:
- a central zone, a first annular zone, a second annular zone, and an edge reconciliation zone,
- wherein the first annular zone is configured to engage at least one topographical aberration on the surface of at least one of the cornea and sclera;
- wherein the second annular zone is configured for corneal reshaping;
- and
- wherein a perimeter of the lens lies within a single plane and is circular.
A method of making a lens comprising:
- obtaining at least one of corneal and scleral elevation data from computer assisted videokeratography and optical coherence tomography;
- selecting the radius of curvature of a central zone based upon the obtained elevation data;
- applying spline mathematics or other curve fitting methods to the obtained elevation data to define a lens annular zone comprised of a plurality of posterior lens radial meridional transitions and at least one rotational transition between said plurality of posterior lens radial meridional transitions;
- and
- cutting a lens from a pre-formed lens button or blank using a lathe, wherein the lens comprises said lens central zone and said lens annular zone, and wherein a perimeter of the lens lies within a single plane and is circular.
A kit comprising a plurality of lenses for use in fitting a plurality of eyes having geometric diversity over at least one of their respective corneal and scleral regions,
- wherein each of said plurality of lenses is comprised of at least one annular zone having a sagittal elevation difference between at least two points located the same radial distance from the center axis of the lens,
- wherein a perimeter of the lens lies within a single plane and is circular, and
- wherein each of said plurality of lenses comprises at least one of a different posterior surface profile and central zone geometry to allow fitting said plurality of eyes.
Dependencies are inferred from the claim text.