HK1007443B - Colored contact lens having very natural appearance - Google Patents

Description

The present invention relates to colored contact lenses and in particular to such lenses having opaque colored portions that are able to change the apparent color of the wearer's iris while imparting a very natural appearance.

It was recognized very early that a contact lens with opaque coloring should not have a simple solidly colored iris. Such a lens imparts a very unnatural appearance. Wichterle in U.S.-A- 3,679,504 discloses an opaque lens having an iris of more than a single color that is artistically drawn or photographically reproduced. Such a lens never achieved commercial success. Other attempts to produce an opaque lens with a natural appearance are disclosed in U.S.-A- 3,536,386, (Spivak); 3,712,718 (LeGrand), 4,460,523 (Neefe), 4,719,657 (Bawa), 4,744,647 (Meshel et al.), 4,634,449 (Jenkins); European Patent Publication EP-A- 0 309 154 (Allergan) and U.K. Patent Application GB-A- 2 202 540 A (IGEL).

Knapp (in U.S.-A- 4,582,402) discloses a contact lens having, in its preferred embodiment, colored, opaque dots. The Knapp lens has been an enormous commercial success. A natural appearance is achieved, yet the lens is simple and inexpensive to produce, using a simple one-color printed dot pattern. At Column 3, lines 23 to 29, Knapp discloses that "For a more natural effect, the printing step may be repeated one or more times using different patterns in different colors, since upon close examination the iris's of many persons are found to contain more than one color. The printed pattern need not be absolutely uniform, allowing for enhancement of the fine structure of the iris." The one-color Knapp lenses currently achieving commercial success have their dots arranged in an irregular pattern to enhance the structure of the iris. However, neither the Knapp commercial lenses, nor the Knapp patent disclose or suggest how one would arrange a pattern of dots having more than one color to achieve a more natural appearance.

The present invention is predicated on the surprising discovery that very simple multiple-color opaque patterns (some of them in accordance with the Knapp disclosure) achieve an amazingly naturally appearing iris. The improvement in appearance over the one-color Knapp lenses, currently achieving enormous commercial success, is startling. Like the one color lenses, the lenses of this invention are able to cause a fundamental change in the apparent color of the wearer's iris, e.g. from dark brown to light blue or green. Although the preferred embodiments of the invention are two-color lenses, use of more than two colors is contemplated.

The present invention relates to a colored contact lens comprising a non-opaque pupil section and a colored iris section having opaque coloring surrounding said pupil section, wherein a first portion of said iris section is of a first shade, and a second portion of said iris section is of a second shade different from said first shade, said first portion is located generally on the outside of said iris section and said second portion is located generally on the inside of said iris section and a jagged border separates said first and second portions, wherein the minimum distance of said jagged border from the outer perimeter of said iris section is from 5% to 45% of the radial width of said iris section, and the maximum distance of said border from the outer perimeter of said iris section is from 45% to 95% of the radial width of said iris section whereby said second portion protrudes into said first portion.

The most preferable dot patterns are as shown in Figures 1 to 6.

The term "non-opaque" as used herein is intended to describe a part of the lens that is uncolored or colored with translucent coloring.

The term "second shade different from said first shade" as used herein is intended to mean that both shades are of totally different colors, such as blue and hazel; or that both shades are the same basic color, but having different intensities such as light blue and dark blue.

The term "ordinary viewer" is intended to mean a person having normal 20-20 vision standing 1.5 m (5 feet) from a person wearing the lenses of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 illustrates a dot pattern very close to the one-color dot pattern of the Knapp lenses currently being sold. As shown below, this pattern may be overprinted to form a lens in accordance with the present invention.

Figure 2 illustrates a preferred dot pattern of an inside portion of dots in accordance with the invention.

Figure 3 illustrates a preferred dot pattern of an outside portion of dots in accordance with the invention.

Figure 4 illustrates a alternative dot pattern for an outside portion of dots in accordance with the invention.

Figure 5 illustrates an alternative dot pattern for an inside portion of dots in accordance with the invention.

Figure 6 illustrates a dot pattern for overprinting lenses in accordance with the invention with a third color.

Figures 7 and 8 illustrate alternative embodiments of iris patterns in accordance with the second and third aspects of the invention, respectively.

DETAILED DESCRIPTION OF THE INVENTION

Contact lenses in accordance with the preferred embodiments of this invention are also in accordance with those disclosed in Knapp's U.S.-A- 4,582,402. Such a prior art lens is illustrated in Figure 1. It has a non-opaque pupil section 20 in the center of lens, and an annular iris section 21 surrounding the pupil section. For hydrophilic lenses peripheral section 22 surrounds iris section 21. A colored, opaque, intermittent pattern is located over the entire iris section 21, as show in Figure 1. The pattern leaves a suostantial portion of the iris section within the interstices of the pattern non-opaque. The non-opaque areas of iris section 21 appear white in figure 1.

The elements of the pattern are preferably dots, and especially preferred are dots, some of which run together, as shown in Figure 1. Certain portions of the iris section 21 are less densely covered with dots than other portions. The less densely covered portions form approximately radial spokes. This arrangement enhances the structure of the iris of a person wearing the lens.

Of course, the opaque pattern may be comprised of dots having any shape, regular or irregular, such as round, square, hexagonal, elongated, etc. Furthermore, the elements of the pattern may have a shape other than dots, so long as the elements are undescrinable to the ordinary viewer, cover at least 25 percent of the iris, and leave a substantial portion of the iris section within the interstices of the pattern non-opaque.

Thus far, this description has covered the Knapp invention of U.S.-A- 4,582,402 and lenses in accordance thereof which have been sold commercially since about November, 1986. The one-color commercial lenses have a pattern that is almost exactly like that of Figure 1, except that the commercial lenses have a smaller pupil section and a wider iris section caused by about two extra rows of dots on the periphery of pupil section 20. That is, the two extra rows of dots, actually present in the commercial lenses, are not shown in Figure 1.

The improvement of this invention is a very simple multiple-color pattern that greatly improves the natural appearance of the wearer's iris, even over that of the one-color lens currently achieving much commercial success. To produce this two-color pattern of this invention, the elements of the pattern (preferably dots) are in two portions. A first portion of the elements are of a first shade and are located generally on the outside of the iris section, i.e. at or near the outer perimeter of the annular iris section. A preferable first outside portion pattern is shown in Figure 3. A second portion of the elements are of a second shade different from the first shade and are located generally on the inside of the iris section, i.e. at or near the inner perimeter of the annular iris section and surrounded by the first outside portion. A preferable second inside portion pattern appears in Figure 2. A jagged border separates the inner and outer portions of the pattern elements. This border need not be precise. Some dots of the first shade may be mixed in with dots of the second shade, so long as there is a jagged border or border zone across which there takes place a noticable change of shade. If the patterns of figures 2 and 3 are merged to form a two-color lens, the jagged outer edge of the pattern of Figure 2 will merge with the jagged inner edge of the pattern of Figure 3 to form the required jagged border between the two portions having different shades.

Producing the opaque portions of the iris section is preferably accomplished by printing the lens twice using the known printing process of Knapp's U.S.-A- 4,582,402. Very briefly, a plate or cliche having depressions in the desired pattern is smeared with ink of the desired shade. Excess ink is removed by scrapping the surface of the plate with a doctor blade leaving the depression filled with ink. A silicon rubber pad is pressed against the plate to pick up the ink from the depressions and then is pressed against a surface of the lens to transfer the pattern to the lens. The printed pattern is then cured to render it unremovable from the lens. Of course, either the anterior or posterior surfaces of the lens may be printed, but printing the anterior surface is presently preferred.

The preferred lenses and inks used to practice this invention are known and described in Loshaek's U.S.-A- 4,668,240. Very briefly, a lens constructured of polymer having -COOH, -OH, or -NH₂ groups is printed with ink containing binding polymer having the same functional groups, opaque coloring substance, and a diisocyanate compound. First a solution of binding polymer and solvent is prepared and this solution is mixed with paste containing the coloring substance to form an ink. The preferred binding polymer solutions described in the Loshaek patent have a viscosity of 25,000 mPa·s (CPS). It is currently preferred to form inks for the present lenses from binding polymer solutions having a viscosity of 40,000 mPa·s (CPS). The opaque ink is printed and cured on the lens surface.

Of course, alternative ways to form colored opaque elements of the lens may be used. For example, selected portions of the iris section of a wetted hydrophilic lens may be impregrenated with a solution of a first substance, such as barium chloride. Then the lens may be immersed in a solution of a second substance, such as sulfuric acid, that forms an opaque, water-insoluble precipitate with the first substance, for example barium sulfate . Thus an opaque precipitate forms within the lens in a predetermined pattern in the iris section. Next all or at least the opaque pattern of the iris section is colored with translucent tint in two colors in accordance with this invention. This provides a lens having a colored opaque pattern in accordance with the invention. If the entire iris is colored with translucent tint, then the interstices within the pattern will be translucently colored, but still non-opaque and in accordance with the first or second aspects of the present invention. Optionally, the pupil section of the lens may be colored by a non-opaque tint, because such tint is not visible when the lens is against the dark pupil present in the eye of the wearer. Other alternative opaquing methods include use of a laser (U.S.-A- 4,744,647) and finely ground particles U.S.-A- 4,460,523.

The following examples illustrate preferred embodiments, but in general, the exact opaque pattern, and the methods of achieving opacity and coloring are not critical to practice of the invention.

In the following examples, all dimensions are for unhydrated hydrophilic lenses. Upon hydration, the lenses expand by a factor of about 1.3 times their unhydrated size. Hence, upon hydration, all dimensions will be about 1.3 times the values that follow. However, the calculated distances of the jagged border from the outer perimeter of the iris section as a percent of the radial width of the iris section will not change upon hydration.

Although preferred lenses of this invention expand by a factor of about 1.3 upon hydration, those skilled in the art will recognize that different lenses having different amounts of expansion upon hydration may also be used.

EXAMPLE 1

A hydrophilic lens made of hydroxyethyl methacrylate, ethoxy ethyl methacrylate, and methacrylic acid as shown in U.S.-A- 4,668,240 is printed on its front, convex side with ink of a first shade containing pigment, binding polymer made from the same monomers used to form the lens, hexamethylene diisocyanate and solvent. The printed pattern is shown in Figure 1. It covers most of the iris section, having an annular form, with an outer radius R¹ of about 5.2 mm and an inner radius R² of about 2.2 mm. After the ink has cured, the first pattern is overprinted with the pattern shown in Figure 2 having a different shade than the pattern of Figure 1. To accomplish this second printing, it is highly preferable to have the centers 23 of the patterns overlap. However, it is not necessary to rotationally align the patterns of Figures 1 and 2. That is, after the figure 1 pattern is printed on the lens, the rotation of the lens or the pad used in printing the pattern of figure 2 about lens center 23 is not important. An attractive lens is produced regardless of this rotation.

The lens pattern of Figure 2 has an inner radius R³ of about 2 mm and a variable outer radius having a maximum of about 4.5 mm at 24 and a minimum of about 2.7 mm at 25. Variations in the outer radius create the jagged outer edge of the Figure 2 pattern. Notice that since the Figure 1 pattern has a has radius R¹ of 5.2mm, the outer pattern extends inward, into the iris section distances of 5.2 - 4.5 or 0.7 mm (minimum) to 5.2 - 2.7 or 2.5 mm (maximum).

The radial width of the iris section is outer radius R¹ minus inner radius R³ or 5.2 mm - 2 mm = 3.2 mm. Hence, it can be seen that the distance of the jagged border from the outer perimeter of the iris section ranges from a minimum of 0.7/3.2 or about 20% of the radial width of the iris section to a maximum of 2.5/3.2 or 80% of the radial width of the iris section. In general, the minimum distance of the jagged border from the outer perimeter of the iris section should be from 5% to 45% (more preferably 10% to 30%) of the radial width of the iris section and the maximum distance of the jagged border from the outer perimeter should be from 45% to 95% (more preferably 60% to 80%) of the radial width. Hence, the outer pattern comprises a substantial portion of the area of the iris and is not merely a thin outer ring at the periphery as described, for example, in U.S.-A- 4,719,657, (Bawa) col. 7, line 56 to Col. 8, line 34. The finished lens of this example will have the Figure 1 pattern overprinted by the Figure 2 pattern and will thus have an outer portion comprised solely of elements of the first shade of Figure 1 and an inner portion comprised primarily of the second shade of Figure 2, but with some of the Figure 1 shade showing through the interstices of the Figure 2 pattern.

Although the exact shades used in practicing the invention are not critical, the shades produced by the Inks shown in the table below are presently preferred. In the above table, the following abbreviations are used:

TiO₂

Titanium Dioxide

FeO (Red)

Red Iron Oxide

FeO (Blk)

Black Iron Oxide

FeO (Yel)

Yellow Iron Oxide

Cr₂O₃

Chromium Sesquioxide

PCN Blue

Phthalocyanine blue (Pigment Blue 15, C.I.74160)

In addition to the pigments, the inks contain binder polymer, solvent, and di- or higher isocyanate compound as described in Loshaek's U.S.-A- 4,668,240. The following specific color combinations are currently preferred: EXAMPLE 2

A contact lens is printed first with the pattern of Figure 3 and then with the pattern of Figure 2 in a second shade. When using these two patterns, centers 23 of both patterns are in alignment and in addition the patterns are rotationally aligned so that radial lines RL¹ and RL² coincide. The following color combinations are currently preferred:

EXAMPLE 3

Contact lenses are printed with the pattern of Figure 4, then with the pattern of Figure 5 in a second shade, and finally with the pattern of Figure 6 in a third shade. Centers 23 of each pattern are aligned and patterns 4 and 5 are rotationally aligned along radial lines RL³ and RL⁴. As seen in Figures 4 and 5, the jagged border between the portions of the iris sections having the first and second shades will be a minimum distance of about 10% of the radial width of the iris section from the outer perimeter of the iris section and a maximum distance of about 80% of the radial width. This border is very jagged and less distinct than the border of examples 1 and 2. The following color combinations are currently preferred:

Example 3A to 3E illustrate three-color lenses.

All of the lenses in accordance with the above examples have a much more natural appearance than the one-color lenses in accordance with Knapp's U.S.-A- 4,582,402, currently achieving enormous commercial success.

EXAMPLE 4

Prepare a lens in accordance with the second aspect of this invention by using the patterns of Figure 7. In Figure 7, an opaque iris section 26 has non-opaque elements 27 (only a few of which are labeled). The non-opaque elements of figure 7 are roughly radially elongated areas and dots. The opaque area has a first section of a first shade and a second inner section of a second shade different from the first shade, separated by jagged border 28.

EXAMPLE 5

Prepare a lens in accordance with the third aspect of the invention by using the patterns of Figure 8. The iris section of the lens is opaque. An outer section 29 has a first shade and an inner section 30 has a second shade. Jagged border 31 separates sections 29 and 30.

Although lenses in accordance with Examples 4 and 5 have not been produced, it is believed that they would achieve a far more natural appearance than the same lenses having a single color. Yet preparing lenses in accordance with these two embodiments is much more simple and much less expensive than attempting to reproduce a natural iris by photographic or artistic means as disclosed by Wichterle in U.S.-A- 3,679,504.

The above examples and the drawings are intended to illustrate, but not limit the present invention, which is as defined in the claims. Numerous variations from the examples and drawings but still in accordance with the invention are possible. For example, the colors and pattern arrangements may be varied. Either the anterior or posterior surface of the lens or both may be printed. The opaque material may be on the lens surface or within the lens, or both. Furthermore, in lenses intended for wearers having lightly colored iris's, the opaque coloring may be merely translucent.

Claims (13)

1. A colored contact lens comprising a non-opaque pupil section and a colored iris section having opaque coloring surrounding said pupil section, wherein a first portion of said iris section is of a first shade, and a second portion of said iris section is of a second shade different from said first shade, said first portion is located generally on the outside of said iris section and said second portion is located generally on the inside of said iris section and a jagged border separates said first and second portions, wherein the minimum distance of said jagged border from the outer perimeter of said iris section is from 5% to 45% of the radial width of said iris section, and the maximum distance of said border from the outer perimeter of said iris section is from 45% to 95% of the radial width of said iris section whereby said second portion protrudes into said first portion.
2. The colored contact lens of claim 1 wherein the opaque coloring of the said iris section is provided by a colored, opaque intermittent pattern over said entire iris section, that leaves a substantial portion within the interstices of the pattern non-opaque, the opaque parts of said pattern covering at least 25 percent of the area of said iris section, the elements of said pattern being undiscernible to a person having normal 20-20 vision standing 1.5 meters (5 feet) from a person wearing the lens.
3. The lens of claim 2 wherein the minimum distance of said jagged border from the outer perimeter of said iris section is from 10% to 30% of the radial width of said iris section, and the maximum distance of said border from the outer perimeter of said iris section is from 60% to 80% of the radial width of said iris section.
4. The lens of claim 2 or claim 3 wherein the elements of the pattern are dots.
5. The lens of any one of claims 2, 3, or 4, wherein the non-opaque interstices are uncolored.
6. The lens of any one of claims 2, 3, 4 wherein the non-opaque interstices are translucently colored.
7. The colored lens of claim 1 wherein the coloring of the iris section is opaque, except for non-opaque elements in said iris section undiscernible to a person having ordinary 20-20 vision standing 1.5 meters (5 feet) from a person wearing the lens.
8. The lens of claim 7 wherein the minimum distance of said jagged border from the outer perimeter of said iris section is from 10% to 30% of the radial width of said iris section, and the maximum distance of said border from the outer perimeter of said iris section is from 60% to 80% of the radial width of said iris section.
9. The lens of claim 7 or claim 8 wherein the non-opaque elements of said iris section are uncolored.
10. The lens of claim 7 or claim 8 wherein the non-opaque elements of said iris section are translucently colored.
11. The colored contact lens of claim 1 wherein the entire iris section has solid opaque coloring.
12. The lens of claim 11 wherein the minimum distance of said jagged border from the outer perimeter of said iris section is from 10% to 30% of the radial width of said iris section, and the maximum distance of said jagged border from the outer perimeter of said iris section is from 60% to 80% of the radial width of said iris section.
13. A lens in accordance with any one of claims 1 to 12 constructed of hydrophilic material.