Contact lens and methods of manufacture and fitting such lenses and computer program product

A contact lens comprising:

• a central zone having a posterior surface with a curvature;
• a connecting zone having a posterior surface provided adjacent and concentric to said central zone, and
• at least one peripheral zone having a posterior surface provided adjacent and concentric to said connecting zone, said peripheral zone being integral with said connecting zone and being formed as a truncated conoid over at least a substantial portion thereof.

A method of fitting a contact lens by adjusting and assessing changes to the sagittal depth of a contact lens having a central zone with a posterior surface having a curvature corresponding in a predetermined manner to the cornea of a wearer, at least one annular peripheral zone and an annular connecting zone, wherein changes in the axial length of the connecting zone produce directly corresponding changes in the sagittal depth of said contact lens.

A method of fitting a contact lens having a central zone with a posterior surface having a central zone with a posterior surface having a curvature corresponding in a predetermined manner to the cornea of a wearer, at least one annular peripheral zone and an annular connecting zone, wherein adjusting and assessing changes to the volume distribution of a void space formed beneath the connecting zone are provided by changing the diameter of the central zone, the axial length of the connecting zone and/or the radial width of the connecting zone without otherwise affecting the fit of the lens.

A method of fitting a contact lens having a central zone with a posterior surface having a central zone having a curvature corresponding in a predetermined manner to the cornea of a wearer, at least one annular peripheral zone and an annular connecting zone, wherein adjusting and assessing changes to the radial location of possible peripheral tangential contact of said at least one peripheral zone to the peripheral cornea are provided by changing the angle made by the peripheral zone to the central axis of the lens.

A method of fitting a contact lens having a central zone with a posterior surface having a curvature corresponding in a predetermined manner to the cornea of a wearer, at least one annular peripheral zone and an annular connecting zone, wherein adjusting and assessing changes to edge lift of said contact lens from the cornea of a wearer are provided by changing the extension of the lens beyond the point of peripheral tangential contact of the lens with the cornea of a wearer.

A method of establishing centration over the visual axis of a contact lens, comprising the steps of adjusting the location of possible peripheral tangential contact and extension of the lens beyond the point of peripheral tangential contact of the lens with the cornea.

A method of fitting, adjusting, visualizing, teaching, assessing and communicating a preferred geometry for a contact lens having a central zone with a posterior surface having a curvature corresponding in a predetermined manner to the cornea of a wearer, at least one annular peripheral zone and an annular connecting zone, wherein a lens set is provided having the central zone diameter, connecting zone width, lens diameter and edge profile provided with predetermined shapes, and measuring the preferred corneal curvature needed to eliminate refractive error for a patient, measuring central corneal curvature of the patient's cornea, and determining the additional parameters of connecting zone depth and peripheral zone angle from fitting or computer modeling to provide a contact lens to reshape the cornea in a desired manner.

A method of manufacturing a contact lens that comprises:

• a computer system, where a specific set of data elements comprised of parameters related to fitting a contact lens having a central zone, a connecting zone adjacent and concentric to said central zone, and a peripheral zone adjacent and concentric to said connecting zone to a patients eye are input, wherein the characteristics in each of central and peripheral zones are independent from one another, and said connecting zone is modeled to transition between said central and peripheral zones,
• a system that processes said data elements and computer lathe parameters and lens cutting data;
• a computerized lathe that utilizes said lathe parameters and lens cutting data to form a contact lens that embodies the user's predetermined specifications.

A method for altering the shape of a patients cornea comprising the steps of:

• determining the desired corrected shape of a cornea, imparting force to said cornea to alter its shape by means of a contact lens comprising a central zone with a posterior surface curvature corresponding to said desired corrected shape, and a first and at least one second annular zones concentric to said central zone, said at least one second annular zone being positioned relative to said cornea and shaped such that upon redistribution of corneal tissue by said central zone, said at least one second annular zone will contact said cornea acting to neutralize forces imparted on said cornea by said central zone, and wherein said first annular zone connects said central zone to said at least one second annular zone.

A method of treating visual acuity deficiencies by wearing a contact lens for an amount of time to modify the shape of the cornea in a predetermined manner, comprising the steps of:

• providing said lens with a central zone having a shape designed to impart force on said cornea, and at least one annular peripheral zone positioned relative to said central zone and shaped to selectively contact said cornea after an amount of redistribution of the corneal tissue by said force applied by said central zone, and an annular connecting zone connecting said central zone with said peripheral zone.

A computer program product for designing a contact lens comprising:

• a computer usable storage medium,
• a computer readable program code means, responsive to user inputs, for modeling said contact lens to have a central zone having a posterior surface curvature selected according to characteristics of a patient's cornea, and a first and at least one second annular zone wherein said at least one second annular zone is positioned and shaped to selectively engage said cornea upon alteration of its shape a predetermined amount, and said first annular zone connecting said central zone and said at least one second annular zone, and
• computer readable program code means for calculating cutting parameters for a lathe used to produce said lens from a blank of material.

41 The computer program product according to claim 40, wherein the fitting set of lenses are selected from the group of fitting lenses having a variable series of base curves with a fixed connecting zone depth and a fixed peripheral zone angle, a fixed base curve with a variable series of connecting zone depths and a fixed peripheral zone angle, variable series of base curves with a fixed connecting zone depth and a plurality of concentric rings, a fixed base curve with a variable series of connecting zone depths and a plurality of concentric rings or having a fixed base curve and a fixed connecting zone depth and a series of peripheral zone angles with or without a plurality of visible concentric rings