Abstract:
A contact lens system, including a peripheral conjunctival cover portion including a shell curved and sized to substantially overly a conjunctiva of an eye. The conjunctival cover portion defines a full thickness central opening therethrough. The central opening is positioned within the conjunctival cover and sized to expose at least a portion of a cornea of the eye. The contact lens system further includes a central contact lens portion that is substantially equivalent in size to the central opening and positioned or positionable at the central opening.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of application Ser. No. 14/539,652, filed Nov. 12, 2014, entitled “Partial Corneal Conjunctival Contact Lens”, which is hereby fully incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates generally to the field of contact lenses and to the field of medication delivery by inserts. 
       BACKGROUND OF THE INVENTION 
       [0003]    Contact lenses have been in existence for many decades. Early contact lenses were made of glass or rigid plastic such as polymethylmethacrylate (PMMA). Early contact lens designs were quite large and referred to as scleral or haptic lens. Scleral or haptic contact lens designs cover the cornea completely as well as covering a large portion of the conjunctiva or sclera of the eye. The sclera is the structural white of the eyeball while the conjunctiva is a transparent tissue which overlies the sclera as well as covering the backside of the eye lids. Early contact lens designs were made of rigid, largely oxygen impermeable polymers as discussed above or a very few of glass. Because cornea physiology was poorly understood at the time these lenses were made, they often cause great discomfort and negative effect on the corneal health. 
         [0004]    As time went by, in the 1950&#39;s, hard contact lenses made of polymethylmethacrylate became much smaller having a diameter significantly smaller than that of the cornea. Hard corneal contact lenses were more comfortable and less physiological damaging than scleral or haptic lenses, but only marginally so. Hard contact lenses still significantly deprived the cornea of a necessary oxygen supply from atmospheric oxygen to maintain good corneal health and were difficult to adapt to. In the 1970&#39;s, so called soft corneal contact lenses became available. Soft contact lenses generally are larger than hard corneal contact lenses having a diameter approximating that of the cornea, somewhat larger than the cornea or somewhat smaller than the cornea. Soft contact lenses are generally made of hydrophilic polymers, such as polyhydroxy ethylmethacrylate (poly HEMA), that absorb substantial amounts of water, saline solution or the tear film. Soft contact lenses also provided improved comfort due to their permeability to oxygen and due to their more flexible nature. Later still, so called gas-permeable contact lenses became available. Gas permeable rigid contact lenses are similar in size and structure to hard corneal contact lenses but are made of rigid oxygen permeable polymers that allow oxygen and other gases to pass through the material of the contact lens to provide improved corneal health. Generally, rigid contact lenses provide sharper vision than soft contact lenses though this is not universally true. 
         [0005]    Hard contact lenses are well as scleral or haptic contact lenses were sometimes fenestrated. That is, tiny holes were drilled or otherwise formed through the rigid contact lens material in an effort to improve tear exchange under the contact lens or to provide a greater availability of oxygen through the contact lens. Fenestration was generally not a very successful technique. Fenestrations, however, were uniformly tiny holes generally much smaller than one millimeter in diameter, occasionally multiple fenestrations were present. 
         [0006]    All contact lenses known to the applicant provide substantially or complete coverage of the cornea of the eye. 
         [0007]    Drug delivery inserts are also known to exist. Drug delivery inserts are small containers into which drugs or pharmaceuticals are placed or absorbed that exist in several different forms. Subpalpebral drug delivery inserts are generally intended to be inserted behind the eye lid in the conjunctival fornices and to gradually release a desired medication to provide a slow, continuous supply of drug to the eye. Subpalpebral drug delivery inserts generally have suffered from being uncomfortable for the patient to tolerate and subject to be accidentally dislodged from the eye by rubbing of the eye or other movements. In addition, subpapebral drug delivery inserts sometimes cause irritation of the conjunctiva or the eye lids. 
         [0008]    Another variety of drug delivery insert is intended to be surgically inserted within the globe of the eye to gradually leach out a steady supply of a desired drug into the intraocular environment. Intraocular drug delivery inserts are less often used due to their relatively invasive nature. 
         [0009]    Generally, drug delivery inserts whether subpalpebral or intraocular have contained a single drug. 
         [0010]    Dry eye syndrome is one of the most commonly treated eye problems in the United States. Dry eye syndrome is also known as keratitis sicca, keratoconjunctivitis sicca (KCS) xerophthalmia, and lacrimal insufficiency. It is estimated that over ten million Americans and  30  million persons worldwide suffer from dry eye syndrome. 
         [0011]    For a large fraction of dry eye patients, dry eye syndrome creates discomfort or annoyance. For those severely afflicted, dry eye syndrome can be debilitating and, in some circumstances, even sight-threatening. In extremely severe cases, dry eye syndrome can even lead to the loss of an eye. 
         [0012]    Dry eye syndrome typically results from deficiency in the quality or quantity of tears produced by the patient. Precorneal tear film has traditionally been considered to have a three-layered structure. Closest to the cornea lies the mucin, or mucus, layer. The mucin layer provides an interface between the corneal epithelium and the remainder of the tear film. Overlying the mucin layer is the watery aqueous layer, which is the thickest layer of the three. The outermost layer of the precorneal tear film is the lipid layer. The lipid layer is an oily film that reduces evaporation from the aqueous layer beneath it. 
         [0013]    The middle aqueous layer provides moisture to the corneal tissue, carries important nutrients, and serves to remove metabolic waste produced by the cornea. Deficiency in any of the three layers of the precorneal tear film can result in complaints of dry, gritty feeling or burning eyes. 
         [0014]    The mucin that forms the mucin layer, nearest the cornea, is secreted by goblet cells in the conjunctiva. The conjunctiva is the transparent tissue that covers the sclera and the backside of the eyelids. The mucin layer functions to decrease surface tension of the tear film. In addition, the cornea itself is hydrophobic. Without the mucin layer to provide a bridge between the cornea and the aqueous layer, the aqueous layer would bead up and allow dry spot formation on the cornea. 
         [0015]    The aqueous layer is secreted primarily by the glands of Wolfring and Krause located in the eyelid margin. The aqueous layer helps provide an optically smooth, transparent surface to the precorneal tear film. The lipid layer is secreted by the meibomian glands, and the glands of Zeiss and Moll. The glands of Zeiss and Moll are also located at the eyelid margin. 
         [0016]    Blinking is essential to maintenance of the precorneal tear film. During each blink, the eyelid wipes over the surface of the cornea, smoothing the mucin layer and spreading the overlying aqueous and lipid layers to provide a completely wetted surface. In between blinks, the tear film thins due to evaporation of the aqueous layer. If evaporation is excessive, dry spots may form on the surface of the cornea. 
         [0017]    Deficiency, or imperfect quality, of any of the three component layers can lead to dry eye symptoms. Many systemic and external factors can contribute to dry eye syndrome. For example, Sjogren&#39;s syndrome is associated with arthritic diseases in combination with dry eye and dry mouth. Deficiency of Vitamin A, use of oral contraceptives and environmental factors can all contribute to dry eye syndrome. Inflammation has also been demonstrated to contribute to dry eye. 
         [0018]    Research into the natural history of dry eye syndrome suggests that the disease progresses through four stages. Each stage is a consequence of the preceding stage. The stages are:
       1. Loss of water from the aqueous layer of the tear film leading to an increase in the tear film osmolarity;   2. Loss of conjunctival goblet cells and decreased corneal glycogen;   3. Increased loss of corneal squamous epithelial cells;   4. Destabilization of the interface between the corneal surface and the tear film.       
 
         [0023]    Either decreased secretion of tear film components or increased evaporation lead to increased tear film osmolarity and the following stages that lead to eventual corneal decompensation and the serious consequences of dry eye syndrome. 
         [0024]    The adnexa of the eye may also be involved in dry eye syndrome. The adnexa of the eye include the structures surrounding the eye such as the eyelids, eye lashes, the tear drainage and tear production structures. Blepharitis commonly contributes to dry eye syndrome. Blepharitis typically results from bacterial infection of the tiny glands in the margin of the eyelid. These glands include the glands of Zeiss, Moll and Wolfring as well as the meibomian glands. Most commonly, the affected glands are the meibomian glands. In bacterial blepharitis, bacterial infection causes the meibomian glands to become plugged, and thus not be able to produce a normal lipid layer to contribute to the tear film. Some bacteria that infect the glands also secrete exotoxins that seep out of the glands into the eye and injure the corneal epithelium. 
         [0025]    Treatments of dry eye syndrome vary depending upon the type of presentation. The most common treatment for dry eye syndrome is the use of artificial tear supplements to provide additional moisture and lubrication to the corneal surface. Artificial tear eye drops are placed on the eye by the patient. Artificial tear supplements must be used regularly and often to be effective. 
         [0026]    Lubricant ointments may also be employed. Ointments are usually used at bedtime because they tend to be messy and blur vision. For some patients, even the use of ointments is not sufficient to provide comfort during sleep. 
         [0027]    Tears drain from the eye through the lacrimal drainage system. Tiny openings at the nasal corner of each upper and lower eyelid are called the lacrimal puncta. The lacrimal puncta lead into ducts that drain into the nasopharynx. 
         [0028]    One treatment for dry eye syndrome is to partially or completely close one or more lacrimal puncta to reduce tear outflow into the lacrimal drainage apparatus. Traditionally, this closure was accomplished surgically or by cautery. In the last decade, however, temporary and permanent punctal occlusion plugs have been utilized. 
         [0029]    Permanent punctal plugs are typically made from surgical silicone; temporary plugs are generally made of soluble collagen. Collagen plugs dissolve over a period of days and are helpful in diagnosis. 
         [0030]    Punctal plugs are placed into the lacrimal puncta, or lacrimal drainage ducts. The plugs impede the outflow of tears from the eye. This approach slows the outflow of tears and retains them in the eyes longer, often relieving symptoms. Punctal plugs have the distinct advantage of being readily removable and avoid the issues of scar formation. 
         [0031]    Blepharitis is sometimes treated by the use of antibiotic medications. Another important treatment for blepharitis is the application of warm soaks and lid scrubs. In this form of treatment, the patient applies a warm wet washcloth to the eyelids for a period of time to provide humidity, warmth and to help soften blockage of and restore flow from the meibomian glands. Lid scrubs are practiced by taking a mild, nonirritating soap and vigorously scrubbing the eyelid margins with they eyes closed, so as to massage the meibomian glands and increase production. The surfactant helps to dissolve the greasy blockage of the meibomian glands. 
         [0032]    Patients who have severe dry eye syndrome often suffer disrupted sleep because they cannot go for longer than an hour or so without applying tear supplements to the eyes. This can lead to pronounced sleep deprivation and a consequent reduction in quality of life. 
         [0033]    A variety of researchers have been seeking other medicinal treatments for dry eye syndrome. Largely, this research is directed at pharmaceutical efforts to increase tear production. 
         [0034]    Accordingly, there is still room for improvement in the contact lens related. 
       SUMMARY OF THE INVENTION 
       [0035]    A partial corneal conjunctiva contact lens according to an example embodiment of the invention includes an annular conjunctival cover in combination with a central lens portion. The central lens portion may be physically separate and used along with the annular conjunctival cover on the eye or may be physically joined to the annular conjunctival cover. The central lens may be of size somewhat larger than a central opening of the annular conjunctival cover and overlap the annular conjunctival cover either anteriorly or posteriorly when the combination of central lens portion and than a central opening of the annular conjunctival cover is applied to the eye. Alternately, the central lens may be somewhat smaller in diameter than the central opening of the annular conjunctival cover and may be positioned within the opening when the central lens and annular conjunctival cover are applied to the eye. In this case the central lens may be a separate structure from the conjunctival cover or may be physically coupled to the annular conjunctival cover. 
         [0036]    For the purposes of this application, reference may be made to the central lens portion or central contact lens portion being substantially equivalent in size to the central opening in the conjunctival cover. This term shall be defined as the central lens having an outside diameter equal to the inside diameter of the central opening or varying by plus or minus five millimeters. 
         [0037]    According to another example embodiment the annular conjunctival cover and the central lens portion are joined as an integral unit with coupling members securing the central lens portion to the annular conjunctival cover and passages between the central lens portion and the annular conjunctival cover permitting fluid flow. The central lens portion may be somewhat larger than a central opening of the annular conjunctival cover and joined to the annular conjunctival cover to overlap the annular conjunctival cover either anteriorly or posteriorly. Thus, the central lens portion may overly or underlie the annular conjunctival cover when the central lens portion is placed on the eye. Alternately, the central lens may be somewhat smaller in diameter than the central opening of the annular conjunctival cover and be coupled within the opening of the annular conjunctival cover. Fluid patent passages that permit the flow of tears between the central lens portion and the annular conjunctival cover are present in each of the above described integral units. 
         [0038]    The annular conjunctival cover in combination with the central lens portion is expected to facilitate tear pumping from the posterior space between the annular conjunctival cover and the central lens portion and the eye to the anterior surface of the annular conjunctival cover and the central lens portion. 
         [0039]    According to another embodiment, the invention includes a method of treating or correcting a patient including applying a conjunctival cover having an opening centrally located therein to the eye and then applying a central contact lens portion over, under or within the opening in the conjunctival cover. 
         [0040]    According to other embodiments of the invention, the central lens portion is coupled to the annular conjunctival cover overlying, underlying or within the central opening at multiple locations. For example, the central lens portion may be coupled adjacent the central opening of the annular conjunctival cover by three coupling members. According to another embodiment, the central lens portion may be coupled to the annular conjunctival cover by four or more coupling members. The coupling members may be arranged symmetrically around or adjacent the perimeter of the central lens portion or may be arranged asymmetrically. For example, three coupling members may be arranged at 120 degree angles around the perimeter of the central lens portion. According to another example embodiment, four coupling members can be arranged at 90 degrees intervals around the perimeter of the central lens portion. According to other embodiments of the invention, coupling members may be asymmetrically arranged. For example, in one embodiment, three coupling members may be arranged at 3 o&#39;clock, 12 o&#39;clock and 9 o&#39;clock which two additional coupling members may be arranged at the 4 o&#39;clock and 8 o&#39;clock positions. The arrangement of coupling members, whether symmetrical or asymmetrical may have an effect on the pumping of tears as the blinking eyelid moves, compresses and releases the corneal conjunctival contact lens system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0041]      FIG. 1  is a schematic depiction of a prior art scleral contact lens; 
           [0042]      FIG. 2  is a schematic depiction of an annular conjunctival cover applied to an eye according to an example embodiment of the invention; 
           [0043]      FIG. 3  is a is a schematic depiction of an elliptical annular conjunctival cover applied to an eye according to an example embodiment of the invention; 
           [0044]      FIG. 4  is a schematic depiction of an elliptical annular conjunctival cover isolated from the eye according to an example embodiment of the invention; 
           [0045]      FIG. 5  is a schematic depiction of a conjunctival cover having an inner ring, an outer ring and a segmented structure according to an example embodiment of the invention; 
           [0046]      FIG. 6  is a schematic depiction of an annular conjunctival cover according to an example embodiment of the invention; 
           [0047]      FIG. 7  is a schematic depiction of a conjunctival cover having a partial inner ring, an outer ring and a segmented structure according to an example embodiment of the invention; 
           [0048]      FIG. 8  is a schematic depiction of a conjunctival cover having a drug reservoir to support drug delivery capability according to an example embodiment of the invention; 
           [0049]      FIG. 9  is a schematic depiction of a conjunctival cover having multiple drug reservoirs to support drug delivery capability according to an example embodiment of the invention; 
           [0050]      FIG. 10  is a schematic depiction of a conjunctival cover having multiple layers according to an example embodiment of the invention; 
           [0051]      FIG. 11  is a cross-sectional view of an embodiment of the invention in situ on an eye including an annular conjunctival cover and a central lens portion overlying the annular conjunctival cover according to an example embodiment of the invention; 
           [0052]      FIG. 12  is a cross-sectional view of an annular conjunctival cover in situ on an eye and a central lens portion underlying the annular conjunctival cover according to an example embodiment of the invention; 
           [0053]      FIG. 13  is a cross-sectional view of an annular conjunctival cover and a central lens portion situated within the opening of the annular conjunctival cover in situ on an eye according to an example embodiment of the invention; 
           [0054]      FIG. 14  is a cross-sectional view of an annular conjunctival cover and an attached central lens portion underlying the annular conjunctival cover in situ on an eye according to an example embodiment of the invention; 
           [0055]      FIG. 15  is a cross-sectional view of an annular conjunctival cover with an attached central lens portion overlying the annular conjunctival cover in situ on an eye according to an example embodiment of the invention; 
           [0056]      FIG. 16  is a schematic plan view of an annular conjunctival cover with an attached central lens portion secured to the annular conjunctival cover via four attachment numbers according to an example embodiment of the invention; 
           [0057]      FIG. 17  is a schematic plan view of an annular conjunctival cover and an attached central lens portion coupled to the annular conjunctival cover by three symmetrically located attachment members according to an example embodiment of the invention; 
           [0058]      FIG. 18  is a plan view of annular conjunctival cover and an attached lens portion attached to the annular conjunctival cover by five asymmetrically located attachment members according to an example embodiment of the invention; and 
           [0059]      FIG. 19  is a plan view of annular conjunctival cover and an attached lens portion attached to the annular conjunctival cover wherein the lens portion neither underlies nor overlies the conjunctival cover. 
       
    
    
     DETAILED DESCRIPTION 
       [0060]    Referring to  FIGS. 11-18 , corneal conjunctival contact lens system  100  generally includes conjunctival cover  102  and central lens portion  104 . 
         [0061]    Conjunctival cover  102  is generally as described elsewhere in this application. Accordingly, conjunctival cover  102  of corneal conjunctival contact lens system  100  may take the form of conjunctival shield  20 , elliptical conjunctival shield  46 , dual ring conjunctival shield  50 , partial inner ring conjunctival shield  66 , drug delivery conjunctival shield  82  or multilayer conjunctival shield  92 . 
         [0062]    Accordingly, example embodiments of corneal conjunctival contact lens system  100  include uncoupled corneal conjunctival lens system  106  and coupled corneal conjunctival lens system  108 . 
         [0063]    Referring particularly to  FIGS. 11-13 , uncoupled corneal conjunctival lens system  106  includes: conjunctival cover  102  and central lens portion  104  which are physically separate structures. 
         [0064]    Referring to  FIG. 11 , uncoupled corneal conjunctival lens system  106  may include overlying central lens portion  110 . According to this embodiment, conjunctival cover  102  is placed on the eye first, followed by overlying central lens portion  110 . Overlying central lens portion  110  includes: bridging portion  112  and overlying portion  114 . Overlying central lens portion  110  is movable with blinking relative to conjunctival cover  102 . Accordingly, the margin between bridging portion  112  and overlying portion  114  is somewhat variable. Bridging portion  112  generally bridges over central opening  116  of conjunctival cover  102 . Overlying central lens portion  110  may be similar in design to soft or rigid contact lens known to those of ordinary skill in the art. Overlying central lens portion  110  may also include features that distinguish bridging portion  112  from overlying portion  114 . Overlying central lens portions  110  also generally includes a central optical zone  118  and a peripheral zone  120 . Optical zone  118  may or may not coincide with bridging portion  112 . Peripheral zone  120  may or may not coincide with overlying portion  114 . 
         [0065]    Referring now to  FIG. 12 , uncoupled corneal conjunctival lens system  106  including underlying central lens portion  122  is depicted. Underlying central lens portion includes opening portion  124  and underlying portion  126 . Underlying central lens portion  122  also includes optical zone  128  and peripheral zone  130  similar to contact lens known to those of ordinary skill in the art. Optical zone  128  does not necessarily coincide with opening portion  124  nor does peripheral zone  130  necessarily coincide with underlying portion  126  though they may coincide. 
         [0066]    Referring to  FIG. 13  another embodiment of uncoupled corneal conjunctival lens system  106  is depicted. In the depicted embodiment, intraopening central lens portion  132  is sized to be somewhat smaller than central opening  134  of conjunctival cover  102 . Intraopening central lens portion  132  is sized to be smaller than central opening  134 . Intraopening central lens portion  132  may be similar in structure and design to conventional soft or rigid contact lens known to those of ordinary skill in the art. Intraopening central lens portion  132  generally includes optical zone  136  and peripheral zone  138 . 
         [0067]    Referring now to  FIGS. 14-19 , example embodiments of coupled corneal conjunctival lens system  108  are depicted. The depicted embodiments include conjunctival cover portion  140  and coupled central lens portion  142 . 
         [0068]    Referring now to  FIG. 14 , posterior coupled corneal conjunctival lens  144  includes conjunctival cover  102  and posterior central lens portion  146 . Referring to  FIGS. 14 and 16-18 , posterior central lens portion  146  is attached to conjunctival cover  102  by attachment members  148 . As depicted in  FIGS. 16-18 , attachment members  148  may be arranged symmetrically or asymmetrically. Attachment members  148  may also vary in size and shape from each other. 
         [0069]    Referring now to  FIG. 15 , anterior coupled corneal conjunctival lens  150  is depicted. Anterior coupled corneal conjunctival lens  150  includes anterior central lens portion  152  coupled to conjunctival cover portion  154 . Similar to the above described example embodiment, attachment members  148  may be oriented symmetrically or asymmetrically as depicted in  FIGS. 16-18 . Further, attachment members  148  may vary in size and shape relative to one another. 
         [0070]    Referring now to  FIG. 19 , another embodiment of coupled corneal conjunctival lens system  108  is depicted. In the depicted embodiment, coupled central lens portion  142  is coupled to conjunctival cover portion  140  by attachment members  148 . Attachment members  148  are separated by and adjacent to openings  156 . 
         [0071]    Referring generally to  FIGS. 1-10 , conjunctival cover  20  according to an embodiment of the invention, generally includes annular shell  22  presenting central opening  24 . Annular shell  22  is formed of a hydrophilic or non-hydrophilic flexible material similar to those used in the manufacture and construction of soft contact lenses. Conjunctival cover  20  is utilized in relation to an eye  26 . Eye  26  generally includes sclera  28 , conjunctiva  30 , cornea  32 , limbus  34  and eyelids  36 . The sclera is the structural white portion of the eye that forms the majority of the eyeball. Conjunctiva  30  overlies the sclera and includes palpebral conjunctiva  40  and bulbar conjunctiva  42 . Palpebral conjuctiva  40  and bulbar conjuctiva  42  meet at fornices  44 . Cornea  32  is the clear front part of the eye and is generally dome shaped in structure. Limbus  34  is the juncture between the edge of the cornea  32  and sclera  28 . Conjunctival cover  20  generally covers bulbar conjuctiva  42  while leaving all or a portion of cornea  32  exposed. For this purpose, central opening  24  is positioned to generally coincide with cornea  32 . Annular shell  22  of conjunctival cover  20  may be sized to extend into fornices  44  or may be smaller in size. 
         [0072]    Referring to  FIGS. 3 and 4 , another embodiment of conjunctival cover  20  is elliptical conjunctival cover  46 . Elliptical conjunctival cover  46  includes annular shell  22  having generally elliptical peripheral margin  48 . Elliptical conjunctival cover  46  may be sized so that elliptical peripheral margin  48  is generally coincident with eyelid margins  38 . Accordingly, elliptical peripheral margin  48  may extend partially under eyelid margins  38  or may be slightly smaller than the space bounded by eyelid margins  38  when eye  26  is open. 
         [0073]    Referring now to  FIG. 5 , another embodiment of conjunctival cover  20  is depicted. Dual ring conjunctival cover  50  generally includes inner ring  52 , outer ring  54 , nasal cover portion  56  and temporal cover portion  58 . Inner ring  52  approximates the corneal diameter being slightly larger or slightly smaller than the limbus. Outer ring  54  is larger than inner ring  52  and may be sized to extend partially or completely into fornices  44 . Inner ring  52 , outer ring  54 , nasal cover portion  56  and temporal cover portion  58  together define arcuate openings  60 . Arcuate openings  60  include superior arcuate opening  62  and inferior arcuate opening  64 . Inner ring  52 , outer ring  54 , nasal cover portion  56  and temporal cover portion  58  may be integrally formed, for example, by a molding process or may be overmolded or otherwise assembled of separate structures. 
         [0074]    Referring now to  FIG. 7 , another embodiment of conjunctival cover  20  is depicted. Partial inner ring conjunctival cover  66  generally includes outer ring  68 , nasal inner ring segment  70 , temporal inner ring segment  72 , nasal cover portion  56  and temporal cover portion  58 . These structure together define central opening  74  which includes superior opening portion  76 , inferior opening portion  78  and central opening portion  80 . Accordingly, when placed upon the eye, partial inner ring conjunctival cover  66  generally covers the nasal and temporal conjunctiva while not covering the superior and inferior conjunctiva which are covered by eyelids  36 . 
         [0075]    Conjunctival cover  20  may also include other fenestrations beyond those identified herein. 
         [0076]    Referring now to  FIG. 8 , another embodiment of conjunctival cover  20  is depicted. Drug delivery conjunctival cover  82  can be similar in structure to any of the above described conjunctival covers  20  but is adapted for drug delivery. 
         [0077]    According to an embodiment depicted in  FIG. 8 , drug delivery conjunctival cover  82  includes first drug reservoir  84 , second drug reservoir  86  and third drug reservoir  88 . Drug delivery conjunctival cover  82  may include one or more drug reservoirs  90 . Drug reservoirs  90  may be formed as cavities within drug delivery conjunctival cover  82  which are bounded by a material that is bio-absorbable or bio-degradable in the eye environment. A wall thickness of first drug reservoir  84 , second drug reservoir  86  and third drug reservoir  88  may vary in order to facilitate timed release of drug dosages. The first drug reservoir may have a thinner wall that is breached by bio-absorption or biodegradation sooner than the thicker walls of second drug reservoir  86  or third drug reservoir  88 . 
         [0078]    Drug delivery conjunctival cover  82  may also be formed of a hydrophilic material that absorbs an aqueous solution of a drug to be released for later diffusion into the ocular conjunctival environment. Thus, drug delivery conjunctival cover  82  may be formed of a poly-HEMA or another hydrophilic material known to those skilled in the contact lens arts. 
         [0079]    Referring now to  FIG. 9 , another embodiment of conjunctival cover  20  is depicted in cross-section. Multi-layer conjunctival cover  92  includes at least first layer  94  and second layer  96 . Multi-layer conjunctival cover  92  may have two or more layers of similar or different construction materials. 
         [0080]    Drugs to be delivered by drug delivery conjunctival cover  82  may include but are not limited to antibiotics, steroids, glaucoma medications, antiviral medications, antifungal medications, NSAIDs, surface lubricants and anti-inflammatories such as cyclosporine. 
         [0081]    Drug delivery conjunctival cover  82  may also be utilized to deliver nano-technology substances into the eye. 
         [0082]    According to another example embodiment the invention includes a method of treating an eye, including applying an annular conjunctival cover to the eye by retracting the eyelids and placing the annular conjunctival cover on a bulbar conjunctiva of the eye while leaving a cornea of the eye substantially uncovered; and releasing the eye lids. 
         [0083]    The method may further include incorporating a drug into the annular conjunctival cover prior to application. 
         [0084]    The method may further include incorporating the drug into the annular conjunctival cover by exposing the annular conjunctival cover to the drug in solution or suspension such that the drug is absorbed into the annular conjunctival cover. 
         [0085]    The method may further include incorporating the drug into the annular conjunctival cover by inserting the drug into a drug reservoir incorporated in the annular conjunctival cover. 
         [0086]    The method may further include inserting multiple drugs into multiple separate drug reservoirs incorporated in the annular conjunctival cover. 
         [0087]    According to another embodiment, the invention includes a method of treating an eye including applying a conjunctival cover portion  102  to an eye and applying a central contact lens portion  104  to an eye and facilitating tear pumping by the relationship between the conjunctival cover portion  102  and central contact lens portion  104 . 
         [0088]    According to another embodiment of the invention, the method may be practiced wherein the central contact lens portion  104  is structurally separate from the conjunctival cover  102  and the method may further include applying the central contact lens portion  104  to the eye prior to and partially underlying conjunctival cover  102 . 
         [0089]    According to another embodiment of the invention, the method may be practiced wherein the central contact lens portion  104  is structurally separate from the conjunctival cover  102  and wherein the method further includes applying the central contact lens portion  104  to the eye after and partially overlying the conjunctival cover  102 . 
         [0090]    According to another embodiment of the invention, the method may be practiced wherein the central contact lens portion  104  is structurally joined to the conjunctival cover  102  and the method further includes applying the central contact lens portion  104  and the conjunctival cover  102  to the eye as a unit. 
         [0091]    According to another embodiment of invention, the central lens portion is structurally joined to the conjunctival cover and the method further includes selecting an arrangement of attachment members  148  joining the central contact lens to the conjunctival cover to be symmetrically arranged whereby tear pumping is facilitated. 
         [0092]    According to another embodiment of the invention, central contact lens portion  104  is structurally joined to conjunctival cover  102  and the method further includes selecting attachment members  148  to be arranged to join central contact lens  104  to conjunctival cover  102  asymmetrically whereby tear pumping is facilitated. 
         [0093]    In operation, various embodiments of conjunctival cover  20  are applied to conjunctiva  30  in a similar fashion to the application of a soft contact lens or a sclera contact lens. Various embodiments of conjunctival cover  20  may be applied to eye  26  by the patient or by a health care professional. Eyelids  36  are pulled open by using the fingers near the eyelids margins  38  and conjunctival cover  20  is placed upon the eye at least partially covering the conjunctiva  30 . As discussed above, various embodiments of conjunctival cover  20  may partially or completely cover the conjunctiva  30  while partially or completely exposing the cornea  32 . Various embodiments of conjunctival cover  20  trap mucin and other tear film components between conjunctival cover  20  and conjunctiva  30 . The tear film also covers the external surface of conjunctival cover  20 . Upon blinking, eyelids  36  and in particular eyelid margins  38  pass over conjunctival cover  20  and both wipes tear film components on the surface of conjunctival cover  20  onto cornea  32  and also squeezes or massages tear film components between conjunctival cover  20  and conjunctiva  30  onto cornea  32 . 
         [0094]    Elliptical conjunctival cover  46  covers conjunctiva  30  substantially between eyelid margins  38 . Dual ring conjunctival cover  50  is placed on eye  26  so that nasal cover portion  56  covers nasal palpebral conjunctiva  40  while temporal cover portion  58  covers the temporal bulbar conjunctiva  42 . 
         [0095]    Partial inner ring conjunctival cover  66  is placed on eye  26  so that nasal cover portion  56  covers nasal bulbar conjunctiva  40  while temporal cover portion  58  covers temporal bulbar conjunctiva  42 . 
         [0096]    Drug delivery conjunctival cover  82  is placed on eye  26  where drugs absorb into drug delivery conjunctival cover  82  diffuse out into eye  26  and surrounding structures. 
         [0097]    In the case of drug delivery conjunctival cover  82  having first drug reservoir  84  and optionally second drug reservoir  86  and third drug reservoir  88 , drug reservoirs  90  dissolve at planned rate to provide time release of contained drugs into the eye. 
         [0098]    Referring to  FIGS. 11-19 , in operation, corneal conjunctival contact lens system  100  is applied on the eye. Referring to  FIG. 11 , uncoupled corneal conjunctival lens system  106 , for example, may be applied by first applying conjunctival cover  102  followed by central lens portion  104 . 
         [0099]    According to another embodiment, uncoupled corneal conjunctival lens system  106  can be applied as in  FIG. 12 . Accordingly, central lens portion  104  is applied to the cornea of the eye followed by conjunctival cover  102 . 
         [0100]    Referring to  FIG. 13 , according to another example embodiment, uncoupled corneal conjunctival lens system  106  may be applied to the eye by applying either conjunctival cover  102  or central lens portion  104  to the eye first followed by the other of conjunctival cover  102  and central lens portion  104 . 
         [0101]    Referring again to  FIG. 11 , overlying portion  114  of central lens portion  104  extends beyond central opening  116  and thus overlies conjunctival cover  102 . 
         [0102]    Referring again to  FIG. 12 , underlying central lens portion  122  of central lens portion  104  underlies conjunctival cover  102  according to this example embodiment. In any of the discussed embodiments, optical zone  128  generally overlies an optical axis of the eye while peripheral zone  130  is peripheral to optical zone  128 . 
         [0103]    Referring again particularly to  FIG. 13 , intraopening central lens portion  132  is sized to fit within central opening  134 . Accordingly, a gap exists between intraopening central lens portion  132  and conjunctival cover  102  according to this embodiment of the invention. 
         [0104]    Referring now to  FIGS. 14-19 , coupled corneal conjunctival lens system  108  is applied to the eye as a unit. 
         [0105]    Referring to  FIG. 14 , posterior coupled corneal conjunctival lens  144  is applied to the eye as a unit. As the eyelid passes over, conjunctival cover portion  140  and coupled central lens portion  142 , it is expected that the tears will be tears are pumped from beneath conjunctival cover portion  140  between conjunctival cover portion  140  and coupled central lens portion  142  and then out to the anterior surface. 
         [0106]    Referring to  FIG. 15 , anterior coupled corneal conjunctival lens  150  is applied to the eye as a unit. As the eyelids pass over anterior central lens portion  152  and conjunctival cover portion  154 , it is expected that the tears will be pumped from beneath conjunctival cover portion  154  between anterior central lens portion  152  and conjunctival cover portion  154  onto the anterior surface of anterior central lens portion  152  and conjunctival cover portion  154 . 
         [0107]    Referring now to  FIG. 19 , coupled corneal conjunctival lens system  108  as in the depicted embodiment, is applied to the eye as a unit. Coupled central lens portion  142  is coupled to conjunctival cover portion  140  by attachment members  148 . Openings  156  are located adjacent to and between attachment members  148 . 
         [0108]    It is expected that the movement of eyelids during blinking will pump tears from beneath conjunctival cover portion  140  and coupled central lens portion  142  through openings  156  to the anterior of coupled central lens portion  142  and conjunctival cover portion  140 . It is also expected, in the case of uncoupled corneal conjunctival lens system  106 , that similar tear pumping will occur. 
         [0109]    According to embodiments of the invention, conjunctival cover  102  and central lens portion  104  may be removed in a similar fashion to soft contact lenses. 
         [0110]    The present invention may be embodied in other specific forms without departing from the spirit of the essential attributes thereof; therefore, the illustrated embodiments should be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.