KR20050032574A - Rotationally stabilized contact lenses - Google Patents

Abstract

Abstract of the InventionThe invention provides contact lenses that incorporate a coaxial stabilization zone to stabilize the orientation of the lens in relation to the eye.

Description

Rotationally stabilized contact lenses

1 shows a plan view of the convex surface of many embodiments of a lens of the invention.

2 shows a plan view of the convex surface of a preferred embodiment of the lens of the invention.

Detailed Description and Preferred Embodiments of the Invention

It has been found in the present invention that a rotationally stabilized contact lens can be obtained by inserting a coaxial stabilization region into the lens, and the common axis for the coaxial stabilization region is the Z axis. The present invention provides a lens using the method for an effective method and stabilization of the lens worn on the eye. In addition, lenses can be manufactured using computer numerically controlled coding without the need for specialized stockpile devices.

In one aspect, the invention

a) defining at least one coaxial stabilization region having a common Z axis to at least one surface of the contact lens;

b) measuring a parameter for at least one or both of one or more thick and thin regions in the coaxial stabilization region; And

c) providing a method of making a contact lens consisting essentially of, comprising calculating a surface design for at least one surface. In another aspect, the present invention provides a contact lens comprising, consisting essentially of and consisting of at least one coaxial stabilizing region having a common Z axis and comprising at least one or both of a thick region and a thin region.

The lens of the present invention may be a hard or soft contact lens. Soft contact lenses are preferred. The coaxial stabilizing region can be located on a convex surface or on the front side, a concave surface or the back side, or both surfaces. The coaxial stabilization zone is preferably present on the convex surface.

The present invention provides for one or more correction characteristics such that, for a custom made lens or eye, such as a lens having a surface derived from a morphometric method or a surface aberration measurement, the orientation on the eye of the lens remains stable in one position. It has been found to be most useful for lenses, ie toric lenses. In the first step of the method of the invention, the stabilization zone is defined, which means that its shape, size and location are limited. In the case of the coaxial stabilization zone, any shape, substantially circular, egg shaped, rhombic and triangular and the like are used, but are not limited thereto. Referring to FIG. 1, a number of broadly diverse possible forms are shown. Preferably, the stabilization region can take a substantially circular shape.

The size and position of the stabilization region extends into any point or lens of the lens edge outside any point or edge of the outer edge of the viewing area. For the purposes of the present invention, "outer edge of the viewing area" means the part of the viewing area that is furthest from the geometric center of the lens. Thus, it represents the furthest periphery point of the central viewing area, which provides corrected vision to the lens wearer. Preferably, the coaxial stabilization region extends from about 0 mm outside the outer edge of the viewing area to about 1 mm inside the lens edge, and more preferably from about 1 mm outside the outside edge of the viewing area to about 1 mm inside the lens edge. Most preferably, the width of the stabilization zone is about 3 to about 6.5 mm.

In a second step, the parameters of at least one or both of thick and thin regions in the coaxial region are measured. More specifically, the position and contour of these areas are measured. The thick and thin areas can be located on any axis. However, if the lens is a toric or custom lens, preferably any thick region may be located below the horizontal axis or 0 and 180 ° lines, and any thin region may be above the horizontal axis. . If at least one or both of the thick and thin areas are used, the thick areas may each be at approximately the same radial distance from the center of the lens, or this distance may be variable, but preferably all of the thick areas are more At the bottom, all thin regions are above the 0-180 ° line.

Preferably, the thin areas useful in the present invention are separate and concave areas below the curved surface of the lens. Similarly, the thick area is a separate convex area that preferably rises above the curved surface of the lens. The regions can be any suitable diameter and the diameter can be determined based on the type of lens used and the degree of rotational stability desired.

Preferably, the thick or thin area begins at or within the inner edge of the stabilization area, which edge is closest to the geometric center of the lens. Each of these areas starts at zero and becomes maximum around the surface of the lens and again zero at the outer edge or edge of the stabilization area or at the edge farthest from the geometric center of the lens. For example, the cross section of a lens passing through a thick area may be described as the height of the area gradually increasing from zero to a maximum above the lens surface and then back to zero. In addition, when moving in an annular parallel around the lens, the thick and thin areas also increase in size from zero to the maximum at the lens surface and back to zero.

Thick and thin regions can take a wide variety of forms, including, but not limited to, substantially circular, egg shaped, triangular, square or polygonal and the like. Preferably, the region is substantially circular or egg shaped, more preferably substantially circular.

Preferably, the number of thick and thin regions used is preferably the minimum number necessary to achieve the desired stabilization and to allow easy manufacture of the lens. Typically, the lens is preferably held in a rotational position for at least about 5 minutes. More preferably, one or two thin regions are used in conjunction with two thick regions.

To determine the contours of thick and thin regions, any periodic function that provides the desired contours can be used. Typically, the contours can be single or double peaks. Suitable periodic functions include, but are not limited to, linear functions and their derivation functions, sine or cosine functions or their derivation functions, exponential functions, Gaussian functions; Conic functions such as circles, ellipses, parabolas, and hyperbolas, dashed functions, splines, polynomial functions of arbitrary order, filter functions, step functions, band filter functions, and the Witch of Agnesi function , Trigonometric functions, suspension line functions, combinations thereof, and the like.

Alternatively preferably, the contour can be derived experimentally as follows. The thickness difference, width, number and position of the lens and the thick or thin area or between these two areas are selected based on the rotational stability desired for the lens. Contours in thick or thin areas are arranged so that the connection with the lens surface is smooth and the lens wearer is comfortable. Preferably, it is selected within the mechanical frequency response characteristics of commercially available CNC lathes with asymmetrical properties such as VARIFORM ^™ lathes (Precitech, Tampa, Fla.).

The maximum thickness or height above the lens surface of the thickened region may be about 100 to about 300 μm, preferably about 100 to about 175 μm. The maximum thickness of the thin area may be about 25 to about 50 μm, which means that the peak of the thin area is about 25 to about 50 μm below the lens surface.

The coaxial stabilization region of the present invention can be formed in a wide variety of ways. Suitable methods are, but are not limited to, adding thickness to or subtracting thickness from the lens surface. 2 shows a lens 10 having a substantially circular stabilizing region 11 and a viewing region 12, which are preferred embodiments. Lens 10 has separate and convex thick areas 13 and 14 at the bottom of the lens, each of which is independently centered at about 210 and 330 ° using a horizontal axis of 0-180 ° as reference. There is this. Region 13 starts at about 165 ° and ends at about 255 ° and region 14 starts at about 285 ° and ends at about 15 °. A separate, concave thin region 15 is located at the top and centered at 90 °. Region 15 starts at about 60 ° and ends at about 120 °. The three regions are spaced at substantially regular intervals and have the same radial distance from the center of the lens.

The calculation of the surface design for the lens can be performed by any known method of designing a contact lens surface. The surface of the lens of the present invention may have various correction visual properties incorporated into one or both of the convex surface and the concave surface. For example, the lens may have one or more of spherical, aspherical, bifocal, multifocal, prismatic or cylindrical correction or combinations thereof. In addition, one or more surfaces of the lens may be a surface calculated from a morphometric method or a surface derived from a morphological method, a surface calculated from a wavefront aberration method, a combination thereof, and the like.

The method of stabilizing a lens by applying the stabilization region of the present invention may depend on the position and shape of the region. For example, in FIG. 2, thick areas act as wedges to stabilize the lens, while thin areas allow the eyelid to be worn more closely to the lens.

The lens of the present invention can be produced by any conventional method for producing contact lenses. For example, the lens design can be cut into metal and the metal is used to make plastic mold inserts for the lens surface. A suitable liquid resin is then placed between the inserts, the insert is compressed and the resin cured to form a lens. In addition, the lens of the present invention can be produced by cutting the lens on a shelf. Those skilled in the art will appreciate the advantages of the present invention in which the lens can be manufactured using on-axis CNC lathing of the lens or using a mold apparatus.

The lens can be made using any material suitable for making contact lenses. Preferably, the material selected for forming the lens of the present invention is a material suitable for forming a soft contact lens. Suitable materials for making contact lenses using the methods of the invention include, but are not limited to, silicone elastomers, silicone-containing described in US Pat. Nos. 5,371,147, 5,314,960 and 5,057,578, incorporated herein by reference. Macromers, hydrogels, silicone-containing hydrogels, and combinations thereof. More preferably, the surface is or is not limited to a siloxane functional group, silicone hydrogel or hydrogel, including but not limited to polydimethyl siloxane macromers, methacryloxypropyl polyalkyl siloxanes and mixtures thereof Etafilcon A.

The invention may be apparent from the non-limiting examples.

Example

Experimentally derive coaxial stabilization zones for lenses with morphologically induced surfaces and one thin and two thick regions. With respect to the geometric center of the lens, the coaxial stabilization zone is approximately 8 mm in inner diameter and approximately 14 mm in outer diameter. Thick and thin areas exist at maximum height and minimum depth, approximately 12 mm above and below the lens surface, respectively. Thick areas are centered at 210 and 330 ° on the lens, and thin areas are centered at 90 °. These regions are present at approximately 120 ° relative to each other.

Lenses incorporating coaxial stabilization regions are made by diamond-punching an insert, making a mold, and casting a lens with etafilcon A. The rotational stability of the lens is tested by wearing the lens in the eyes of 10 individuals and observing the lens with a Slit Lamp Biomicroscope. The lens is inserted in the intended orientation at 45 ° relative to the nose and temple, in an orientation 180 ° different from the intended orientation. At least 5 minutes after stopping the rotation, the final position of each lens is evaluated for orientation and for stability in that orientation.

As a result, coaxial stabilization was found to be superior in terms of both the comfort of the wearer and the final position of the lens closer to the intended orientation than conventional stabilization methods.

Field of invention

The present invention relates to a contact lens. In particular, the present invention provides a contact lens comprising a coaxial stabilization region that stabilizes the orientation of the lens in relation to the eye.

Background of the Invention

It is known that correction of certain visual defects can be achieved by imparting aspheric correction characteristics to the contact lens, such as cylindrical, bifocal or multifocal characteristics. In addition, technological advances have allowed the manufacture of lenses or custom lenses based on individual corneal topographic measurements or wavefront measurements, or both. The use of custom lenses or lenses with specific correction characteristics can be problematic for the eye to be effective while keeping the lens in a specific orientation. However, the lens can rotate over the eye due to gum bleed as well as eyelid and tear movement.

Lenses designed to maintain orientation over the eye of a lens typically exist in two general forms. One form uses prism stabilization or enlargement of certain lens portions to maintain orientation. Examples of prism stabilization methods include decentralization of the front face to the lens back, prism balancing, enlargement of the lower lens edge, support of the lens on the lower eyelid, formation of depressions or protrusions on the lens surface, and cutting of the lens edges. .

Dynamically stabilized lenses, the second type of lens, use eyelid movement to maintain lens orientation. Dynamic stabilization involves reducing the thickness of the lens outer surface in two symmetrically lying areas, enlarging the two outer areas on the central horizontal axis, and thinning or rolling off the upper and lower areas on the lens. .

Known methods for maintaining lens orientation require specialized, off-axis tooling in the manufacture of lenses using these methods, which lenses are inconvenient to wear and the known methods are very proportional. It has several disadvantages, including Thus, there is a need for a method of maintaining each orientation that overcomes some or all of these shortcomings.

Claims (27)

A contact lens having at least one coaxial stabilizing region having a common Z axis and comprising at least one or both of a thick region and a thin region. The contact lens of claim 1, wherein the contact lens is a soft contact lens. The contact lens of claim 2, wherein at least one coaxial stabilizing region is present on a convex surface, a concave surface, or both surfaces. The contact lens of claim 2, wherein the coaxial stabilization region is on a convex surface. The contact lens of claim 2, wherein the coaxial stabilization region is substantially circular. The soft contact lens of claim 2, wherein the coaxial stabilization region extends from about 0 mm outside the outer edge of the viewing area to about 1 mm inside the lens edge. The contact lens of claim 2, wherein the surface on which the coaxial stabilization region is located is a surface calculated from topographic measurement, wavefront measurement, or a combination thereof. The contact lens of claim 2, wherein the surface on which the coaxial stabilization region is located is a surface calculated from a morphology test. The contact lens of claim 2, wherein the surface on which the coaxial stabilization region is located is a surface calculated from wavefront aberration measurements. The method of claim 7, wherein the coaxial stabilization zone comprises a separate concave thin region centered at about 90 ° and a separated thick convex first area centered at about 210 °, the separation And a thick, convex second area centered at about 330 °. The contact lens of claim 10, wherein the coaxial stabilization region is substantially circular. 10. The method of claim 7, wherein the coaxial stabilization zone is a separated and concave thin first region centered at about 60 °, a separated and concave thin second region centered at about 120 ° and about 225. A contact lens comprising a separate, thick, convex first region centered at °, the separated, thick, convex second region centered at about 315 °. 13. The lens of claim 12, wherein the coaxial stabilization region is substantially circular. At least one coaxial stabilizing region having a convex surface, a concave surface, and a common Z axis, and located at one or both of the convex and concave surfaces, wherein the coaxial stabilizing region comprises at least one or both of a thick region and a thin region. And the surface on which the coaxial stabilization region is located is a surface calculated from a morphology test, a wavefront aberration method, or a combination thereof. The soft contact lens of claim 14, wherein the coaxial stabilization region is on a convex surface. 15. The soft contact lens of claim 14, wherein the surface on which the coaxial stabilization region is located is a surface calculated from morphology. The soft contact lens of claim 14, wherein the surface on which the coaxial stabilization region is located is a surface calculated from wavefront aberration measurement. 18. The soft contact lens of claim 14, wherein the coaxial stabilization region is substantially circular. 19. The method of claim 18, wherein the coaxial stabilizing region comprises a separate concave thin region centered at about 90 degrees and a separate thick thick convex first region centered at about 210 degrees, wherein the second thick convex region is separated. Soft contact lens centered at 330 °. 19. The method of claim 18, wherein the coaxial stabilization zones are separated and concave thin first regions centered at about 60 ° and separated and concave thin second regions centered at about 120 ° and separated and thick centered at about 225 °. A soft contact lens comprising a convex first region, wherein a separate, thick, convex second region is centered at about 315 °. 15. The soft contact lens of claim 14, wherein the coaxial stabilization region extends from about 0 mm outside the outer edge of the viewing area to about 1 mm inside the lens edge. A convex surface, a concave surface, and one or more substantially circular coaxial stabilizing regions located on a convex surface having a common Z axis and extending from about 0 mm outside the viewing area to about 1 mm inside the lens edge, wherein the coaxial stabilizing area is thick; and A soft contact lens comprising at least one or both of the thin regions, wherein the convex surface is a surface calculated from morphology, wavefront aberration, or a combination thereof. The soft contact lens of claim 22, wherein the surface on which the coaxial stabilization region is located is a surface calculated from a morphology test. 23. The soft contact lens of claim 22, wherein the surface on which the coaxial stabilization region is located is a surface calculated from wavefront aberration measurements. The method of claim 22, wherein the coaxial stabilization zone comprises a separate, concave thin region centered at about 90 ° and a separated thick convex first area centered at about 210 °, and is separated Soft contact lens with a thick, convex second area centered at about 330 °. 25. The method of claim 22, wherein the coaxial stabilization zone is a separated and concave thin first region centered at about 60 ° and a separated and concave thin second region centered at about 120 ° and about 225 °. A soft contact lens comprising a separate, thick, convex first region centered at and wherein the separated, thick, convex second region is centered at about 315 °. a) defining a coaxial stabilization region to one or more surfaces of a contact lens having a common Z axis and comprising at least one or both of a thick region and a thin region; b) measuring parameters for at least one thick region within the coaxial stabilization region; And c) calculating a surface design for at least one surface.