WO1990014056A1

WO1990014056A1 - Artificial eye, scleral shell, contact lens or the like

Info

Publication number: WO1990014056A1
Application number: PCT/GB1989/001457
Authority: WO
Inventors: Abhijit Roy; Brian Alan Rowell
Original assignee: Abhijit Roy; Brian Alan Rowell
Priority date: 1989-05-19
Filing date: 1989-12-06
Publication date: 1990-11-29
Also published as: CA2031683A1; GB9124480D0; GB2248399B; GB2248399A; AU4746290A

Abstract

The invention provides a process of manufacture of an article such as an artificial eye (10, 110, 210) scleral shell, contact lens or the like, wherein a portion (16) of the article is provided by producing a photograph of a corresponding portion of a natural eye, and incorporating that photograph in the article so as to constitute that portion of the article. The invention also provides an article manufactured by such a process.

Description

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Title: "Artificial eye, scleral shell, contact lens or the like"

This invention relates to a process of manufacture of an article such as an artificial eye, scleral shell, contact lens or the like, and to an article manufactured by said process.

Where a person's natural eye has been so badly damaged, or has ς deteriorated to such an extent, as to necessitate complete removal of the natural eye, the natural eye is commonly removed from the eye socket and replaced by a cosmetic "artificial eye", now usually made from organic plastics material, which is shaped so as to be retained naturally in the eye socket and which from the front has an external appearance mimicking that IQ of the lost eye, in that it provides a portion corresponding to the sclera, that is the hard firm "white" of the eye. and a portion corresponding to the iris of the eye. It will be appreciated that in a real eye the iris is generally coloured, defines the pupil of the eye, and lies behind a transparent front portion, the cornea, of the eye.

I r Generally, replacement of only one eye is required, and there is a need to ensure that the artificial eye is a satisfactorily good match to the other eye. Thus there is a need to ensure that the colour and generally delineated appearance of the iris portion of the artificial eye, are a satisfactorily good match to the real iris of said other eye. and that the colour and detailed 0 appearance of the scleral portion of the artificial eye are a satisfactorily good match to the real sclera of said other eye. A good match is particularly necessary because even if a slight mis-match exists which would not be noticed by most onlookers, the wearers themselves, when they look in a mirror, often become acutely aware of any mis-match, leading to serious 5 psychological problems such as distress, withdrawal or the like.

This problem is complicated by the fact that hitherto, artificial eyes have been produced by laborious processes involving intricate hand-painting, at considerable cost, of the iris and scleral portions of the artificial eyes, and wearers often have to wait many months for this process to be completed. 0 Not only is this wait itself a cause of distress, the additional distress caused if it is found, when the artificial eye is eventually received, that the αrtificiαl eye is α poor match to the wearer's remaining natural eye is considerable, particularly since repetition of the conventional manufacturing process is again very slow and laborious. The iris is particularly difficult to match. Similar problems arise where the damage or deterioration of an eye is not sufficient to warrant its complete removal, in which case it is normal practice, instead of removing the eye, to provide a "scleral shell", namely a generally part-spherical (generally less-than hemispherical) cap-like body which is received against the front surface of the damaged or deteriorated natural eye, with its edges received behind the upper and lower eye lids, and which has a generally white scleral portion to provide a cosmetically- improved appearance for the sclera of the eye, and an iris portion to provide a cosmetically-improved appearance for the iris of the eye. Where the wearer still has sight in the eye concerned, the scleral shell is generally provided with a transparent pupil portion to permit vision through the shell.

In any such shell, the iris and scleral portions are again conventionally produced by being painted by hand, and again similar problems arise in terms of cost and the difficulty of achieving a good match with the other eye.

Other cases where the cosmetic appearance of eyes may be changed involve contact lenses.

Contact lenses are commonly formed from transparent material, such as relatively hard plastics material or, increasing commonly, soft flexible plastics material. Whilst most contact lenses are intended to serve the purpose of correcting a wearer's defective vision, contact lenses are now available in a variety of coloured tints with the alternative or additional object of enabling the wearer to modify the apparent colour of the irises of his or her eyes. Usually this colour modification is for cosmetic purposes, including remedying a natural mis-match between the eye colours.

It is an object of the invention to overcome or reduce the above problems.

According to the present invention, there is provided a process of manufacture of an article such as an artificial eye, scleral shell, contact lens or the like, wherein a portion of the article is provided by producing a photograph of a corresponding portion of a natural eye, and incorporating that photograph in the article so as to constitute that portion of the article. In this manner, an article manufactured in accordance with the invention may be of exceptionally natural appearance.

Said portion of the article may correspond to the iris of the natural eye or to the sclera of the natural eye, or to such iris and sclera in combination. Where the article is an artificial eye or scleral shell, said portion of the article may correspond to the iris and sclera, in combination.

At least in preferred artificial eyes and scleral shells in accordance with the invention, the portion of the photograph actually included in the article includes at least the iris and the iris-to-sclera transitional region. In this manner, an iris-to-sclera transitional region of exceptionally natural appearance may be achieved in the article.

In preferred embodiments of artifical eye and scleral shell in accordance with the invention, the peripheral border of the portion of photograph to be included in the article at least substantially coincides with the outer edge of the iris-to-sclera transitional region in the photograph.

At least in a preferred artificial eye in accordance with the invention, the photograph is accommodated in a recess, preferably formed with an undercut edge, formed in the body of the artificial eye.

Where the article is a contact lens, said portion of the article wil l generally correspond to the iris alone, excluding the sclera or the iris-to- sclera transitional region.

Preferably the photograph at least as ultimately used in the article, is to 1 : 1 (i.e. unit) or generally 1 : 1 scale, in comparison with a natural eye.

In some embodiments the photograph may be produced initially to an at least substantially 1: 1 scale compared with the natural eye, whilst in other embodiments the photograph is initially produced to a sub- l : l scale and undergoes a stretching and shaping operation.

Desirably the photograph is a colour photograph obtained by a process achieving reproducible high accuracy of colour rendition. Thus, where a person still has one "good" eye, the photograph may be a high colour-accuracy photograph of at least the iris (and for some articles manufactured in accordance with the invention, of the sclera also) of the person's "good" eye, so that when the photograph is incorporated in the article concerned, a faithful match will be perceived with the colour and delineated or otherwise detailed appearance of the "good" eye when the αrticle is worn in place of, or on, the damaged or deteriorated eye, so that the above described psychological problems may be avoided.

It will be appreciated that the process in accordance with the invention is far more rapid (hours or days at the most) than prior processes involving hand-painting of at least the artificial iris.

Furthermore, should, for some reason, a mis-match be obtained, it is a relatively straight-forward and swift matter to repeat the process in accordance with the invention, minimising inconvenience to the wearer. Reproducibility is important, to enable a replacement of at least

10 substantially identical colour and appearance to be provided should the original article supplied be damaged or lost.

In the course of manufacture in accordance with the invention the photograph may undergo process stages involving heating. In preferred processes in accordance with the invention, the iris portion of the photograph

15 is re-touched with a dye, such as a pale cyan dye, before the photograph undergoes a heating stage of the process. In this manner, the colour of the iris in the photograph may be unaffected by such heating, leading to substantially improved reproducibility of results. The dye may be a photo re¬ touching dye.

20 Preferably the photograph is provided in the form of a direct photographic print (i.e. made optically from a photographic positive or negative) on a substrate of photographic material, which substrate advantageously affords a white or generally white base, whereby, in particular, the perceived brightness of the artificial iris, as seen by reflected

^•" light, may match that of a natural iris.

Thus the print may be made upon conventional photographic paper e.g. comprising a front surface (e.g. gelatin) incorporating/carrying the photographic emulsion, and a paper (or the like) rear surface. Whilst the print may be incorporated in the article without removal of said rear surface,

™ desirably the rear surface is removed at least from a peripheral area of the portion of the photograph actually to be included in the article, prior to incorporation of said portion in the article. Removal of the rear surface from said peripheral area prevents the photograph from having a hard peripheral edge. Where only the peripheral area of the rear surface is

^■" removed, general ease of handling of the photograph is unimpeded. In some embodiments, however, the entire rear surface may be removed. The rear surfαce, or appropriate area thereof, may be removed from the front surface by suitable physical or chemical means; processes for lifting the gelatin/emulsion layer of photographic paper from the paper are known, and may for example involve the peeling or scraping of successive paper layers 5 from the rear surface of the paper, until substantially only the gelatin/emulsion layer remains.

It will be appreciated that the surface of certain artificial eyes or scleral shells in accordance with the invention, or the general form of a contact lens, is or may be curved. 10 In order to produce the then required curvature, the photograph (e.g. the separated gelatin/emulsion layer) may in some embodiments be "vacuum formed" into the required curved shape by suction onto a former, or onto the article itself. Alternatively or additionally, such curvature may be produced by manually and/or mechanically pressing the emulsion layer against such 15 former or article, preferably with the photograph disposed between a pair of protective sheets during such pressing. In any event, heat may be applied if necessary to facilitate any stretching which may be required.

Although in the case of artificial eyes or scleral shells, the material of the photograph may adhere naturally to the material of the artifical eye or -"-^ shell, the photograph is preferably secured thereto by a varnish, and then preferably coated externally with that varnish. A final coating of a plastics resin is preferably applied to seal the artificial iris and/or sclera on the artificial eye or shell. Such a coating may be a clear acrylic.

In general terms, the photograph is preferably mounted directly on the " front surface of a rear portion of the article, and a material which, in the finished article, is transparent is then applied over the photograph.

Alternatively the photograph could be encapsulated prior to incorporation (e.g. incorporation in a screw-in manner) in a recess in the article. ^ A very important feature of preferred processes in accordance with the invention is that the photograph is produced by photographing the natural eye using flash illumination arranged such that the reflection of the flash in the eye appears strictly on the pupil, so as not to mar the image of the iris.

Thus, where the photograph is to be incorporated in e.g. an artificial

^■" eye, the reflection may easily be re-touched out using a black dye, whilst in contact lens applications, or in scleral shell applications where through-vision is required, the reflection is lost when the photograph is perforated suitably to provide an optically clear pupil, prior to incorporation in the article.

In a suitable method of photographing the natural eye, the photograph is taken along an axis arranged at least substantially normal to the front of the eye, and the flash illumimation is provided by a co-axial ly disposed ring flash.

In the case of a contact lens the photograph may be sandwiched within contact lens material.

Where the article is an artificial eye, scleral shell or the like, an artificial scleral surface of desired colour may be afforded afforded through formation of a body of the article from a material of that colour.

The invention also provides an article manufactured by a process in accordance with the invention.

Several articles embodying the invention will now be described, by way of example only, with reference to the accompanying drawings in which: FIGURES la and lb are respectively cross-sectional and front elevational views of a first artificial eye embodying the invention;

FIGURE 2 is a cross-sectional view of a second artifical eye embodying the invention;

FIGURE 3 is a cross-sectional view of a third artificial eye embodying the invention;

FIGURE 4 is a cross-sectional view of a scleral shell embodying the invention;

FIGURE 5 is a cross-sectional view of a contact lens embodying the invention; and FIGURE 6 is a cross sectional view of a mould, in use for the manufacture of the lens of Figure 3.

Referring first to Figures la and l b of the drawings, a first artificial eye 10 in accordance with the invention comprises a body 12 of organic plastics material having a front surface 14 corresponding in shape and size generally to that of a natural eye. The body 12 is painted white or is white by virtue of said material (e.g. polymethyl methacrylate) being white.

In use, the artificial eye 10 is positioned in the eye socket of the wearer, to replace the natural eye, for cosmetic purposes.

The artificial eye 10 further comprises a layer 16 which covers a slightly protruding front-most portion 18 of the surface 14 and in this case also covers a generally annular portion 20 of surface 14 lying around the portion 18. In comparison with a natural eye, the portion 20 corresponds to the white or sclera of the natural eye, and the portion 18 to the cornea behind which the iris and pupil of the natural eye would be located.

A transparent layer 22 of hardened resin seals the layer 16 onto the body 12. The layer 16 affords both an artificial iris and pupil, and in this example further affords an annular portion of an artificial sclera surface, as will now be described.

In order to manufacture the layer 16, a colour photograph is taken of the iris and surrounding area of sclera of the wearer's "good" eye, which the artificial eye is required to match, and is printed on a slightly less than 1 : 1 scale (i.e. a slight reduction compared with the "good" eye), in this example by printing optically from a basic photographic positive or negative image, onto photographic paper of a naturally white colour. It will be appreciated that in order for this photgraph to be taken, the lids of a wearer's "good" eye should be held apart.

Further details of the manner in which the photograph can be taken are described later, but it should here be noted that the photographic process used is such that a reproducible high accuracy of colour rendition, and fine detail rendition, are obtained. A colour bar code/chart, such as are supplied by some photographic manufacturers, may be used to check the accuracy of colour and tone rendition. Typically this would involve photographing a multi-coloured test chart adjacent to the eye under idential conditions of lighting and exposure, and adjusting the photographic printing process until the printed image of the chart conforms to the original chart, then making the photographic print of the eye using identical photographic printing parameters.

By a physical or chemical process a front layer of the photographic paper, carrying the gelatin/photographic emulsion and hence the final image, is then separated from the rear layer(s) of the paper, and this front layer, trimmed appropriately around its outer periphery, constitutes the layer 16.

In this example the paper is a "gloss" paper, for example paper with a "resin coated" front surface, and the front layer is separated by carefully peeling off successive paper layers from the rear surface of the paper until substantially only the gelatin/emulsion front layer remains. In some cases this front layer may be only about 2 micrometres in thickness. In order to produce α curvature in the initially flat layer 16 to enable it to conform to the surface 14 (which surface 1 may correspond in shape to a natural eye of the wearer, by virtue of being formed using a cast made from that natural eye), the layer 16 is formed into the required curved shape at least primarily by suction (i.e. "vacuum forming") onto a former of suitable shape (e.g. made from said cast), or onto the surface 14 itself, heat and/or manual or mechanical pressure being applied if necessary to facilitate any stretching of the layer 16 which may be required. Such stretching involves slight enlargement of the photograph (for the iris portion, by about 8% in terms of diameter), and for this reason an initial scale for the photograph of slightly less than 1: 1, such as about 92%, is advantageous, to give a 1 : 1 (i.e. unit) scale on stretching.

Where the layer 16 is shaped directly on the body 12, the layer 16 is positioned beforehand on the body 12 by way of an alignment mark, such as a dot provided on the fore-most point of the portion 18, to correspond to the pupil of the image on the layer 16. A similar mark may be used where the layer 16 is first shaped on a former other than the body 12.

Although the gelatin of the layer 16 has a tendency to adhere naturally to the body 12, the layer 16 is secured to the body 12 by an acrylic varnish and then coated externally with that varnish. A liquid clear acrylic resin is finally applied over the front of the layer 16 and surrounding surface 14 to seal the layer 16 on the body 12, and seal the entire front surface of the artificial eye, the resin hardening to afford the layer 22 after a matter of minutes or hours. Such resin may for example be liquid acrylic (requiring heat curing) or ultra-violet fixed resins. Such liquid acrylic (non-toxic) may be obtained from the field of dentistry where it is used in repairing holes/cracks in teeth or dentures.

Thus, in the artificial eye 10 so obtained, the image of the wearer's good iris constitutes the iris, and pupil, of the artificial eye, and because of said high accuracy colour rendition, assisted by said essentially 1:1 final size and said fine detail, affords an artificial iris which matches the iris of the "good" eye better than has hitherto been possible with manual "painting" techniques, and with a time requirement of only hours or days per eye rather than months, so that the frequent distress caused by mis-matches and delays regarding conventional artificial eyes is avoided. Similar considerations apply in relation to the portion of artificial sclera also provided by the layer 16, since the artificial sclera can also be difficult to match to that of the "good" eye by conventional techniques: a wide range of sclera colours exist, together with differing degrees of fine detail (e.g. fine blood vessels) from one sclera to another. An alternative approach to provision of an artificial sclera is hereinafter described in relation to the second and third embodiments of the invention.

A benefit of including a portion of artificial sclera in the layer 16 of the eye 10 is that an iris-to-sclera transition of natural appearance is obtained. A second artificial eye 1 10 in accordance with the invention is illustrated in Figure 2 of the drawings, and corresponds to the artificial eye 10 hereinbfore described (corresponding parts being correspondingly numbered) except that the layer 16 of the eye I 10 covers only the slightly protruding front-most portion 18 of the surface 14, so as to contribute essentially only an artificial iris and pupil to the eye 1 10. The remainder of the surface 14 provides an artificial sclera of suitable colour by virtue of being painted and/or by being moulded from material (e.g. opaque acrylic) of suitable colour, as will hereinafter be explained more fully in relation to the third embodiment. The peripheral border of the layer 16 in the eye I 10 coincides with the outer edge of the iris-to-sclera transitional region in the photograph, so that in the eye I 10 an exceptionally natural appearance is still obtained for the iris-to-sclera transition.

Since the layer 16 of the eye 1 10 affords essentially only the iris and pupil, so as to be only of about I I or 12 millimetres or so (for an adult) in diameter, the curvature in the layer 16 of the eye 1 10 may be produced differently, namely by heating two I mm thick sheets of clear acrylic each 50 mm square with an infra-red lamp, placing the gelatin layer 16 between these sheets, and then manually and/or mechanically pressing the sheets, with the layer 16 between them, against the front-most portion of a positive cast made from a natural eye of the wearer. The pupil centre of this cast is marked with a dot, to ensure perfect positioning of the layer 16 during shaping. Said acrylic sheets are then discarded, the sheet 16 retaining its curvature.

A third artificial eye 210, being a preferred form of artificial eye in accordance with the invention, is illustrated in Figure 3 of the drawings.

Parts of the eye 210 which are at least in part analogous to those of the eyes 10 and 1 10 hereinbefore described are correspondingly numbered. Importαnt features of the artificial eye 210 are that: (i) In the eye 210 the layer /photograph 16 affords only the iris and the pupil;

(ii) In the eye 210, the layer 16 is flat, so that the aforementioned stretching and shaping of the layer 16 is not required;

(iii) The body 12 of the eye 210 is of coloured (e.g. white or off-white) acrylic material which itself determines the basic colour of the artificial sclera afforded thereby, fine detail such as capϊlliaries being hand painted, this being a relatively easy task compared with painting the entire artificial sclera; and

(iv) The layer/photograph 16 is accommodated within a generally cylindrical recess, the edge of the recess importantly being undercut.

The layer /photograph 16 of the eye 210 corresponds generally to that of the eye 1 10, except that in the eye 210, the photograph, provided and used in a flat state, is accurately to 1: 1 scale (preferably to within about 2% of 1 : 1 scale), since no stretching or shaping of the photograph is required in this embodiment. The peripheral border of the layer 16 of the eye 210 again corresponds to the outer edge of the iris- to sclera transitional region in the photograph. At the start of manufacture of the eye 210, the artificial eye maker is provided with:

(i) Said photograph of the natural eye, the print (which will afford the layer 16) being initially uncut and showing the iris/pupil and the surrounding sclera (showing scleral capilliary detail, but sometimes, due to the need to print an accurate-colour iris, the difference in brightness of the iris and sclera, and limitations of the photographic printing process, not showing the sclera colour absolutely accurately);

(ii) A cast made (where possible) from the wearer's natural eye which is to be replaced, giving the shape required for the surface 14, and having the position of the pupil centre marked thereon, and

(iii) An indication of the true colour of the sclera, the latter having been ascertained by direct comparison of the sclera of the wearer's good eye with a colour comparison chart or set of coloured filters, (viewed against a white card) giving all likely sclera colours, from white/colourless to various off-white shades of yellow, pink, or blue for example. Using α drill/cutter having an annular cutting edge of the correct diameter, the iris-plus-pupil portion of the photographic print is cut out of the print, the line of the cut following the outer edge of the iris-to-sclera transition zone on the print, to afford the layer 16 for the eye 210, the remainder of the print being retained for reference to scleral detail. (If it is desired to remove the rear layer(s) of photographic paper, this is conveniently done before cutting of the print.)

Next, a hole of about 2mm depth is drilled in the aforesaid cast supplied, in the position of the pupil-centre mark, and a 2 mm clear acrylic rod is placed in this hole, so as to protrude therefrom. A wax model (i.e. a negative impression) is then made of the thus modified cast.

Using the information supplied on the scleral colour, an acrylic material of that colour is then chosen (or mixed) and the opaque body 12 of the eye 210 is then cast from said acrylic material, using the wax model as a mould. (In practice, two bodies 12 may be cast, one being kept safely in reserve, for use in the event that any mishap should befall the first.) It should be noted that wax does not adhere to acrylic.

Said cast body 12 at this stage includes a protrusion corresponding to the aforesaid acrylic rod, and this protrusion is then severred and a generally cylindrical recess R, centred on the mark left by the severred protrusion, is then drilled to a depth of about 2 mm in the body 12. Typically the recess R is of about 12 mm diameter. An undercut 205 of about 0.25 to about 0.5 mm radial extent (preferably only about 0.25 mm) is then produced in the otherwise generally cylindrical side wall of the recess R, for example using a hand held precision drill (such as dentistry drill) or the like.

The layer 16 is then secured in the recess R using "molopoly" (an acrylic varnish), and acrylic tints and paints are then used manually to match the details of the sclera to those on said remainder of the photograph.

A clear transparent acrylic "button" 200 is placed over the layer 16, in the position shown in Figure 3, and secured in place using an acrylic varnish.

The button 200 may be provided with an integral transparent acrylic "handle" (not shown) protruding from its front, to facilitate holding and placement of the button 200, which handle may be severred after positioning. (The handle if not severred, will in any case blend visually imperceptibly into the acrylic layer 22 when the latter is applied.) A 2 mm or so thickness wax sheet (not shown) is then placed over the entire front surface of the body 12 and the body is then encased in a mould (not shown) of suitable material (such as a plaster-like material known as "dental stone"). With the body 12 still in that mould, the wax sheet is boiled off and clear (and colourless) acrylic is then poured into the cavity left by the wax, between the mould and the body 12, to provide the clear acrylic layer 22, the mould being opened as soon as the layer 22 has had time to solidify (curing of the layer 22, and of the entire eye 210, may be achieved by boiling in water at about I00°C, in said mould, for about 15 to 30 minutes, preferably for about 20 minutes.)

The cured eye 210 then undergoes final surface grinding and polishing, to provide a high quality smooth external surface finish.

A particular advantage of the artificial eye 210 is that since the layer 16, corresponding to the iris-plus-pupil is accommodated in the recess R, below the normal level of the surface 14, with the periphery of the layer 16 lying in or adjacent to the undercut 205 in the edge of the recess, and with said periphery corresponding to the outer border of the iris to sclera transition zone in the photograph, the iris to sclera transition in the completed eye 210, and moreover the eye 210 as a whole, is of exceptionally natural appearance.

In relation to each of the above embodiments, and the further embodiments hereinafter described, the photographs concerned may be taken using what in scientific/laboratory equipment terms is relatively inexpensive apparatus, such as a 35mm camera provided with a suitable lens and film and situated at a suitable measured and/or predetermined distance from the eye to be photographed.

A suitable lens, for example, is the 200 mm focal length Nikon "Medical Nikkor" lens which has a built-in shadowless coaxial ly disposed "ring flash" for photographic illumination purposes and which is pre-calibrated with various magnification factors to enable a precisely controlled and reproducible magnification factor and exposure to be obtained whenever, and wherever, such a lens is used. This "Medical Nikkor" lens is capable of optically printing the selected magnification factor on the photographs, as they are taken, which provides confirmation that the correct magnification factor was selected. The photographs are taken with the axis of the lens arranged at least substantially normal to the front of the eye. In some cases, the photographs may be taken with a suitable "instant- print" Polaroid-type camera so as to produce the photograph, for incorporation in the article, directly.

Where the photograph used in an article in accordance with the invention is a print made from a basic photographic positive, printing papers which may for example be used include that known as "Cibachrome" which gives prints of very high colour quality, which subjectively appear very "real" and in which dark or black areas in particular subjectively appear to have a "depth", the latter point being significant where provision of an artificial pupil is concerned.

Preferably, however, the photograph is taken on a colour negative film (e.g. "Kodak Ektacolor" ASA 1 0, processed by the standard "C-41 " process), and printed on resin-coated photographic paper, which paper is relatively inexpensive and also, by virtue of its lesser thickness and the fact that it is resin coated rather than plastics laminated, relatively easy to handle and less susceptible to accidental marking. The image scale on the negative, compared with the subject, may be approximately 1 :2.75 for example, and said print(s) may be made using a "miniprinter" of adjustable calibrated magnification ratio to produce prints of accurate 1 : 1 scale compared with the subject (where the layer 16 will not need to undergo stretching) or of accurate 92% scale (for example) where subsequent stretching is required.

In order to ensure an acceptable match between the natural and artificial eyes under at least the majority of lighting conditions, the photograph of the natural eye should be taken under average-brightness ambient lighting so that the pupil of the natural eye does not appear unusually small or unusually large when photographed. Ambient lighting determines the pupil size in the photograph, the eye not having sufficient time to react to any flash used for the photograph during the taking of the photograph. Illumination of the natural eye by flash or tungsten light sources during taking of the photograph entails risk of a "highlight" appearing in the photographic image due to reflection of the flash or tungsten light source in the eye. Using the aforementioned ring flash, however, any such highlight appears strictly over the pupil, rather than over the iris and may easily be "touched out" of the final print by (say) two applications of black photoprint retouching dye, any excess dye being wiped off after each application to keep the print surface smooth. Theoretically flash can illuminate the retina, which could marr the image of the pupil, but with the ring flash this has not been found to occur significantly. In an alternative arrangement the photograph is taken without flash inside a translucent "tent" illuminated externally by natural light or by a plurality of tungsten light sources, arranged to reduce any risk of highlights appearing.

A very important feature of the invention with regard to reproducibility concerns the avoidance of colour changes in the photograph during stages of manufacture (e.g. curing at about 100° C) which involve heating. Such colour changes are avoided, in the present invention, by re-touching the iris portion of the photograph with a dye prior to such stage of the process involving heating. Such dye may be a very pale grey/neutral, or preferably cyan (which is usually the colour of the uppermost dye layer of photographic paper), dye, for example suitably pale or diluted photo re-touching dye, which may be applied essentially as a "wash" over the photograph. Such dye itself may have only a barely discernible colour, so as not to affect the colour accuracy of the photograph, and yet has the remarkable effect of preventing any discernible change in colour of the photograph during subsequent heating. Furthermore, the presence of the dye, in combination with the covering of the photograph in acrylic prior to curing, enable curing to occur without physical harm to the photographic paper, in spite of the temperatures involved. The dye may be applied in conjunction with a photographic "wetting agent" to assist the dye in making direct contact with the photographic paper.

Referring now to the further embodiments of the invention illustrated in Figures 4 to 6, the particular scleral shell illustrated in Figure 4 is produced in a similar manner to the above-described artificial eye 10, but may be worn over an existing "bad" natural eye. Parts of the shell corresponding to parts of the eye 10 are similarly numbered. Where the natural eye is still sighted, a hole is produced in the photographic layer 16 before incorporation into the shell, to afford an optically clear pupil through which sight may still be obtained. A suitable resin, such as that described above for the artificial eye(s), is used to retain the layer 16 of the shell on the body 12 of the shell. In the shell illustrated, the layer 16 affords the artificial iris-plus pupil, and the artificial sclera surface, as in the eye 10, but an alternative layer 16 may be utilised if desired, in the same manner as in the eye 1 10, to provide only the artificial iris-plus-pupil, the sclera then being self-coloured αnd/or painted, as in the eye 1 10. As in the eyes 10 and 1 10, the layer 16 of the shell of Figure 4 is printed fractionally below full size, and then stretched/shaped to the required size and curvature in analogous manner(s). Referring now to the contact lens shown in Figure 5, in which similar numbering is again used, in this lens the photographic layer 16 is incorporated between two layers, integral at their edges, of a soft contact lens organic- plastics-material (e.g. polyhema) "button". Such soft contact lens material is rendered "soft", ready for wear, by absorption of water thereby, and in its dry state is sufficiently rigid to be machined to the required front and rear curvatures on a lathe.

In relation to the example of Figure 5, the layer 16 for use in the lens illustrated usually comprises only an artificial iris portion, which in use overlies only the natural iris of a wearer, but is produced photographically, and stretched/shaped to the required size and curvature, essentially in the manners described in relation to the layers 16 of the artificial eyes 10 and 1 10 and scleral shell described above.

The layer 16 for the lens however is initially cut over-size so as to include sufficient non-iris peripheral edge portion for it to be positioned by that edge portion in a mould M (Figure 6) into which the soft contact lens material is injected through inlet A in a molten state, the material then solidifying in the mould. Excess solidified material is then machined away on a lathe, after removal from the mould, to produce the lens to suit a person's eye curvature and/or vision. Alternatively such a contact lens may be manufactured by taking a basic meniscus of clear acrylic contact lens material ( preferably having a rear surface already of the necessary curvature) and adhering the iris photograph to its front surface, and then applying a thin dough-like layer of clear acrylic over the photograph, to encapsulate the photograph. A female mould having the desired shape of the front of the lens is then applied over the dough-like layer, to shape the front of the lens and to press the layers of the lens together, and the lens is then polymerised by boiling the lens-and- mould combination in water at about I 00°C for about 20 minutes. The mould is then removed and the front layer of the resulting lens may subsequently be machined, if necessary. As an alternative, the rear surface may initially be flat, and may be machined to shape after polymerisation. Such α contact lens can be worn over a natural eye, to change the apparent iris colour (e.g. to cure a natural mis-match) to mask iris/pupil damage, or for other cosmetic reasons, and benefits, in terms of the apparent brightness of the eye, from the natural white basis of the photographic paper emulsion used for the layer 16. In these latter uses, the centre of the layer

16 is perforated prior to incorporation in said material, to provide a pupil.

Such lenses may be purchased in pairs by some people, to change the colour of both irises, and a stock of unmachined such lenses may be kept, to be machined as necessary to suit a given wearer. In each of the above examples, the acrylic (or other) layer(s) in front of the layer 16 helps to provide some protection against incident ultra-violet light, and so helps to prevent fading of the pigmentation of the layer 16 over a period of time. Advantageously, however, to ensure long-term retention of pigmentation, an extra layer could be included, such as directly in front of the layer 16, and below the outer layer of the article, said extra layer for example comprising an ultra-violet filter layer (i.e. which blocks passage of ultra-violet light) such as a "Wratten" gelatin ultra-violet filter.

In alternative embodiments of the invention, advantageously the rear surface of the photograph is removed, in a progressive manner, only from the peripheral area of the portion of the photograph actually to be included in the article. This prevents said portion, when incorporated in the article, from having a peripheral edge of visible thickness, while the general ease of handling of the photograph during manufacture is unimpeded. A hand-held pencil/ink eraser may be used for said progressive removal. Although the "photograph" could alternatively be a fine-screen lithographic print made using a plate or plates made from an original photographic positive or negative, preferably direct photographic prints, made purely optically, are used as in the detailed embodiments described above. It will be appreciated that in each of the above examples, the invention provides at least an artificial iris, and in some cases an artificial sclera portion also, with a minimum of trouble, cost and time, and with little risk of distress to wearers. It will be appreciated that the reduced cost of articles in accordance with the invention is a most important factor, particularly to Health Authorities who often meet the cost of artificial eyes, scleral shells or, in appropriate circumstances, contact lenses. Moreover, it should be appreciated that compared with the cost of providing such articles conventionally, apparatus for putting the invention into effect may be relatively inexpensive.

Furthermore, a "bank" of iris photographs covering a wide range of iris colours, sizes and levels of detailed structure may be established, from which a suitable iris photograph may be selected, to suit a given wearer, for incorporation in an article in accordance with the invention, for that person.

The invention, in its broadest sense, includes a situation where the photograph is a computer-generated image, for example a faithful reproduction of the appearance of at least a portion of a natural eye, or a computer processed or generated image which conveys the impression of being an image of at least a portion of a natural eye.

Further alternative features of the invention, and further advantages of the invention, are as set out in the introductory part of this specification.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, or a class or group of substances or compositions, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

C AIMS:

1. A process of manufacture of an article such as an artificial eye, scleral shell, contact lens or the like, wherein a portion of the article is provided by producing a photograph of a corresponding portion of a natural eye, and incorporating that photograph in the article so as to constitute that portion of the article.

2. A process according to Claim I wherein the photograph is produced by photographing the natural eye using flash illumination arranged such that the reflection of the flash in the eye appears strictly on the pupil.

3. A process according to Claim 2 wherein the photograph is taken along an axis arranged at least substantially normal to the front of the eye, and the flash illumination is provided by a co-axially disposed ring flash.

4. A process according to Claim I wherein the photograph is a colour photograph having reproducible accuracy of colour rendition, and said portion of the article corresponds at least to the iris of the natural eye, the iris portion of the photograph being re-touched with a dye prior to a stage of the process involving heating.

5. A process acccording to Claim I wherein the photograph is in the form of a print made upon photographic paper comprising a front surface incorporating or carrying the photographic emlusioπ, and a rear surface, and the rear surface is removed at least from a peripheral area of the portion of the photograph actually to be included in the article, prior to incorporation of said portion in the article.

6. A process according to Claim I wherein the portion of photogaph actually included in the article includes at least the iris and the iris-to-sclera transitional region.

7. A process according to Claim 6 wherein the peripheral border of the portion of photograph to be included in the article at least substantially coincides with the outer edge of the iris-to-sclerα transitional region in the photograph.

8. A process according to Claim I wherein the photograph is produced initially to an at least substantially 1 : 1 scale compared with the natural eye.

9. A process according to Claim I wherein the photograph is initially produced to a sub I : I scale and undergoes a stretching and shaping operation.

10. A process according to Claim I wherein the photograph is mounted directly on the front surface of a rear portion of the article, and a material which, in the finished article, is transparent, is then applied over the photograph.

I I. An article manufactured by a process according to any one of Claims I to 10.