Abstract: The invention relates to a novel process for producing mouldings, especially contact lenses, which comprises the following steps: a) preparing a substantially aqueous solution of a water-soluble prepolymer that contains crosslinkable groups; b) converting the resulting solution into the solid state; c) introducing the resulting solid-state solution into a mould; d) converting the solid-state solution into the liquid state in the mould; e) where applicable closing the mould; f) initiating the crosslinking; g) where applicable opening the mould, so that the moulding can be removed from the mould.

Abstract: Unsaturated polyester resin-based ophthalmic lens compositions that are modified for unexpected improvement in speed of manufacture while maintaining uniform, low optical distortion and/or improved tint speed by the addition to the polyester composition of at least one photoinitiator, preferably having at least some activity at a wavelength above about 380 nm so that a UV-absorbing compound can be included in the polyester lens composition, and the polyester resin composition is photocured to gelation in about 7 minutes or less, e.g., using a light intensity of at least about 300 microwatts/cm.sup.2, more preferably at least about 500 microwatts/cm.sup.2, most preferably at least about 1,000 microwatts/cm.sup.2.

Abstract: A method for manufacturing materials solidified with sulfur, comprising the steps of bringing the water content of a mixture of sulfur and a raw material to less than 3% by weight, heating and mixing the mixture of raw materials including molten sulfur at 119 to 159.degree. C., to cause the sulfur to penetrate and encapsulate the raw material that is solid or liquid at the molecular level, thereby preparing a fluid mixture, and, if necessary, then molding the mixture into a desired shape or cooling it into a granular form.

Abstract: A method of treating contact lenses made from polymerizable materials by providing supercritical fluids to the lenses.

Abstract: A contact lens production line pallet system transports contact lens mold materials throughout a facility for producing ophthalmic lenses. Specifically, the contact lens production line pallet system includes a pallet for carrying one or more contact lens mold assemblies throughout a contact lens production line, the pallet having one or more first recesses formed in a surface thereof for receiving either a first mold half or a complementary second mold half, the first and second mold halves when placed together constitute an individual contact lens mold assembly. A conveyor device for transporting the pallet from station to station throughout the production line facility is provided, as is a locating device formed in the pallet surface for enabling precise positioning of the pallet at one or more manufacturing stations in the production line facility.

Abstract: An injectable intraocular lens composed of a silicone material is disclosed. The silicone lens material is polymerized from a plurality of siloxane monomers. The silicone lens material has a specific gravity great than 1.0 and a refractive index of a natural lens.

Abstract: A cast-molding material for a plastic lens which is almost free from causing defective dyeing when dyed, and a process for producing plastic lenses almost free from causing defective dyeing, the cast-molding material containing, as essential components, a combination of (A) diethylene glycol bisallylcarbonate or a mixture of diethylene glycol bisallylcarbonate and a monomer copolymerizable therewith, with (B) a polyether-modified silicone compound, and the process including cast-molding the above cast-molding material in a mold.

Abstract: New intraocular lenses (IOLs) and methods for producing IOLs are disclosed. The present methods include a combination of steps which increase the pull strength between the fixation member of the IOL and the optic of the IOL without requiring sophisticated high frequency corona discharge activation or plasma activation or other exotic activation of the fixation member or primer coating of the fixation member. The silicone polymeric optic members employed in the present invention can be formed, for example, molded, without recesses to accommodate the fixation members. Such recesses can be formed and provided with a quantity of silicone polymeric material precursor composition after the optic members are produced. The fixation members are then placed in the recesses and secured to the optic members. The present methods are straight forward, easy to practice and are cost effective in producing high quality IOLs.

Abstract: A process for preparing a soft, tinted lens is described. The process comprises the steps of softening and tinting a xerogel lens 1, wherein the softening and the tinting are achieved by immersing the xerogel lens 1 in a single solution 5 capable of softening and tinting the xerogel lens 1.

Abstract: The present invention relates to making optical articles such as opthalmic lenses by molding and, in particular, to using a continuous extrusion-compression molding method to make plastic lenses whereby a polymer melt is fed from an extruder or melting apparatus to a first die of a plurality of rotating or conveyed sequentially processed compression die sets comprising a first die and a second die. The die sets are positioned on die supports on a rotating turntable or conveying system, the lenses formed by compressing the die sets with pressing means associated with each die support, the lenses separated from the dies and the dies recycled to die loading and the melt feed step of the process and the process repeated until the desired number of lenses or other optical articles such as compact disk substrates are produced.

Abstract: For the fast and rational manufacture of moulded articles, specifically contact lenses, that are partly colored or have regions of different colors, by the casting process, measured amounts of two or more crosslinkable materials of different colors are introduced into the casting mould in the uncrosslinked stated unmixed and, after closing the casting mould, are crosslinked together. By suitably controlling the introduction of the different crosslinkable materials with regard to location and/or time the merging of the colors and the transitions between the colors in the contact lens are influenced in a controlled manner.

Abstract: The process for making an antenna lens having a lens core and a coating layer surrounding it includes making a stiff shell (1,2) forming a lens coating layer in a predetermined shape suitable for the antenna lens so that the stiff shell has a hollow space, and filling the hollow space of the shell with a flowing, powdery or paste-like material to form the lens core.

Abstract: A collagen containing substrate comprising cattle basal membrane is conditioned by incubating the membranes in a mixture of pepsin, hyaluronidase and acetic acid and separating the collagen from the mixture. The mixture can include pepsin, hyaluronidase and a 0.5M solution of acetic acid in 1:1:10 proportions. The incubation is conducted for about 10 hours at about 45.degree. C. After incubation, collagen is separated from the mixture by centrifuging at a speed of 5000 to 30000 rpms for about 30 minutes. The collagen is mixed with polymerizable monomer and polymerized to form a gel that can be ground to form an intraocular or contact lens.

Abstract: A method for separating one mold section from another mold section and a contact lens molded in the two mold sections provides improved reliability that the lens is not damaged during this operation and that the lens is retained selectively on the desired. Various embodiments of apparatus for carrying out the method are disclosed.

Abstract: A method is provided for the manufacture of a holographic eye-covering article, the eye-covering article having an interference pattern corresponding to a predetermined three-dimensional object holographically prerecorded in a planar hologram layer, the interference pattern capable of being "played back" to an observer without being "played back" to said bearer. Functionality of the eye-covering article is effected in part by a light transmissive eyepiece, the eyepiece being uniaxially-curved and preferably comprising in sequence a thin web, a planar layer comprising the holographically prerecorded interference pattern, an adhesive layer, and a rigid optical substrate.

Abstract: A method for manufacturing precise complex three dimensional structures in which minute drops of both a product layer and a sacrificial layer are emitted from an acoustic device. The process is a two step process wherein first the three dimensional structure is built in layers which are composed of either a sacrificial layer or a product layer or some configuration of both. Once the structure has been completely built up, then the sacrificial layer is removed leaving only the complex three dimensional structure.

Abstract: A die for press-molding glass optical elements comprising (a) a base material having heat resistance and sufficient strength to withstand press-molding of optical glass elements; (b) a film on said base material comprising an alloy film containing B and one metal selected from the group consisting of Ni, Co, and Fe, and one metal selected from the group consisting of Si, Ti, Cu, Zr, Nb, Mo, Ru, Rh, Pd, Hf, Ta, W, Re, Os, and Ir, to form a cutting layer; and (c) a surface protective layer on top of said cutting layer made of an alloy film comprising at least one metal selected from the group consisting of Pt, Pd, Ir, Rh, Os, Ru, Re, W, and Ta.

Abstract: A method for manufacturing preforms used in molding optical elements includes: (1) forming an array made from a material for optical elements, in which a plurality of preform portions used in molding optical elements are connected; (2) applying vibration to the outer peripheral part of the preform portion in the thickness direction of the array by a pair of punches; and then (3) punching the preform portions.

Abstract: Various configurations of a directed energy assisted micro embossing machine/station in a vacuum chamber utilized in a continuous manufacturing process and the web structure products made by that process (optical disks, cards, tapes, holographic reflectors, diffusers, binary optical elements, etc.) are disclosed. The configurations can include a single machine roll to roll system for embossing optical features on the surface of a single substrate and applying appropriate metallic, dielectric, semiconductor, polymer and other coatings all in a vacuum chamber.

Abstract: A molding method for optical element is disclosed in which a glass material prepared for weight is introduced into a mold and then heated to soften, and subsequently pressed with the mold to mold an optical element. The glass material is heated to have a viscosity of 10.sup.5 to 10.sup.7 dPaS and press-molded with the mold having a temperature equivalent to a viscosity of 10.sup.9 to 10.sup.11 dPaS of the glass material.

Abstract: Use of monovalent salts of saturated and unsaturated fatty acids C.sub.10 -C.sub.18 as external lubricants in granules formulation based on acrylic polymers for injection molding at temperatures from 180.degree. C.-220.degree. C. of articles having a thickness greater than 10 mm, preferably the lubricant amount is from 10 to 100 ppm; and related compositions.

Abstract: Lens surfaces are transferred by press-molding a glass material (16) by an upper mold (1) and a lower mold (2). After the lens surfaces are transferred, the outer circumferential portions of the upper and lower molds (1, 2) are clamped and pressed sideways to correct a shift between the optical axes of the transfer molding surfaces of the upper and lower molds (1, 2) and an inclination of the optical axes.

Abstract: A method for mechanically stabilizing and for tuning a filter having a photonic crystal structureThe cavities of the filter fabricated as a photonic crystal structure are filled with optically transparent material having an adjustable refractive index. The optical properties of the filter and, thus, the filtering action are adjusted by way of an electric field having a variable field strength.It is possible to produce small-dimensioned, narrow-band filter elements, which are finely tunable and tunable within a broad range, and to realize them as filter elements which are integrated with a high packaging density.

Abstract: A method and apparatus for curing lenses involves supporting mold assemblies containing lens-forming mixture on plates, where the plates are stacked vertically with sufficient clearance to separate adjacent plates of mold assemblies.

Abstract: There is provided a very thin light guide plate for a surface light source device and a method of manufacturing it without the use of high-precision molding machine. A surface light source device using this light guide plate generates outgoing light having high uniformity. According to the manufacturing method, a light guide plate free from a weld line or warp can be manufactured with good transferring characteristics. The light guide plate is thick on an incident surface 1 side and thin on a lower surface 4 side. At the central portion of an incident surface 1 in a longitudinal direction, a projecting portion obtained by cutting an overhang portion 7 at a position a distance D apart from the incident surface 1 is formed. The cut surface of the projecting portion is not made specular and is kept rough. In molding of the light guide plate, a molten material is supplied from the position of a gate mark 9.

Abstract: A method is provided for forming a strippable or dissolvable release coating on the surface of substrate such as a flexible polymeric film or web. The release coating is subsequently coated with a layer of material and then dissolved in a solvent to release the layer. The release coating is made from a copolymer of methylmethacrylate and ethylacrylate or from a homopolymer of polyacrylic acid. Release coatings made of methylmethacrylate and ethylacrylate copolymers having glass transition temperatures of about 60.degree. C. or greater, or made of a ipolyacrylic acid homopolymer having a glass transition temperature of about 100.degree. C. or higher, are also provided. The release coatings provide excellent supporting substrates for the formation of an overcoated metallized layer, are readily strippable in acetone, and can be formed during an in-line process which begins with drawing a flexible film or web from a molten polymeric material.

Abstract: A method of injection molding contact lens molds for cast molding contact lenses having a rotationally asymmetric lens surface, and apparatus for carrying out the method, are disclosed.

Abstract: A method for producing moisture-containing soft contact lenses by polymerizing monomers for contact lenses in the presence of a diluent for monomers and substituting the diluent contained in the resulting polymer with an aqueous solution, wherein the diluent is composed of one or more compounds selected from the group consisting of triethylene glycol, diethylene glycol monomethyl ether and triethylene glycol monomethyl ether and a moisture-containing contact lens composed of a copolymer of the following main components, (1) two or more kinds of hydrophilic monomers selected from the group consisting of 2-hydroxyethyl methacrylate, N-vinyl-2-pyrrolidone and N,N-dimethylacrylamide, (2) an alkyl methacrylate and (3) a crosslinkable monomer, and an aqueous solution, which has a moisture content of 50-70% and exhibits a penetration strength of 1100 gf/mm or more. The contact lens of the present invention is optically transparent and exhibit excellent mechanical strength.

Abstract: A method for making optical preforms of optical elements without residual stress or distortion is provided. In this method, an optical material is supplied between upper and lower molds. The upper mold has a plurality of recesses arranged in a predetermined pitch, and each recess corresponds to a first surface shape of the optical element. The lower mold has a plurality of recesses facing the recesses of the upper mold and each recess of the lower mold corresponds to a second surface shape of the optical element. The supplied optical material is pressed between the upper and lower molds to be a set of optical preforms. The set of optical preforms is processed by die punching or tool cutting to separate each optical preform from the set of optical preforms. Each optical preform is used for producing an optical element by further pressing. Alternatively, optical element can be formed directly by the press molding process.

Abstract: A glittering non-retroreflective sheeting 60 includes an array of cube-corner elements 30 that are arranged in the array such that the sheeting glitters when light is incident thereon. The glitter is in the form of many discrete points of light 68 that tend to blink off and on. The array may be configured such that a dihedral angle .alpha. varies between adjacent cube faces 31 of adjacent cube-corner elements 30 in each groove in one of the groove sets 45, 46, or 47 and such that the base plane 36 are not parallel to each other when the sheeting 60 is laid flat. Preferably, the dihedral angle .alpha. between faces 31 of adjacent cube-corner elements 30 varies in essentially all of the grooves such that the cube-corner elements are randomly tilted throughout the array. The glitter can make the sheeting very useful for aesthetic or decorative applications.

Abstract: Method and device for producing lenses of microoptical systems and an optical emitter/receiver system. A curable liquid lens material is introduced into a mount which serves as a lens holder for the lens to be produced, and a convex lens surface is formed at an opening of the mount. The lens material introduced into the mount is irradiated with light during its introduction. An optoelement which forms part of the microoptical system is arranged relative to the lens at a position which it shall assume in the completed microoptical system. Simultaneously with the introduction process, either the image of a light emitter as the optoelement is measured in a selected plane at the side of the mount opposite the optoelement, or the signal intensity of the signal which is changed in an optical sensor as the optoelement as a result of incident light, and the introduction process is terminated when the image or the signal has reached a predetermined size and/or shape.

Abstract: The present invention relates to polymerizable derivatives of carbohydrates comprising a carbohydrate radical and more than one radically polymerizable hydrocarbon group which is linked optionally via a spacer to the carbohydrate radical, to homopolymers, copolymers, block copolymers, graft copolymers and polymeric networks thereof, to capsules, fibers, films and coatings having water-binding and biocompatible properties, and to molded articles, for example contact lenses or biomedicinal articles, comprising the mentioned polymers, as well as to processes for the preparation of the mentioned polymers and articles.

Abstract: A plastic optical-fiber is provided having a desired length and a desired graded refractive index. To this end, a base polymer is mixed with a non-polymerizable compound having a higher refractive index to obtain a fiber material. This material is then transformed continuously into a fiber in a fiber-preparing unit. A plurality of diffusion tanks are each provided with a solution, each solution having a level of viscosity different from one another. The fiber is then dipped successively into the solutions in the order from a lowest viscosity level to a higher viscosity level. During this process, the non-polymerizable compound and polymerizable compound diffuse inside the fiber and form a graded refractive index distribution. The polymerizable compound is then polymerized and hardened in a drying-and-heating unit. The fiber thus obtained is drawn and coated with a cladding.

Abstract: A collagen containing substrate comprising cattle basal membrane is conditioned by incubating the membranes in a mixture of pepsin, hyaluronidase and acetic acid and separating the collagen from the mixture. The mixture can include pepsin, hyaluronidase and a 0.5 M solution of acetic acid in 1:1:10 proportions. The incubation is conducted for about 10 hours at about 45.degree. C. After incubation, collagen is separated from the mixture by centrifuging at a speed of 5000 to 30000 rpms for about 30 minutes. The collagen is mixed with polymerizable monomer and polymerized to form a gel that can be ground to form an intraocular or contact lens.

Abstract: The invention features a method of making a gradient-index polymer rod involving the steps of: combining a polymer with an additive, wherein the refractive index of the polymer material is different than the refractive index of the additive material; extruding the polymer and the additive into a polymer rod having a substantially uniform index of refraction profile; and immersing the rod having the substantially uniform index of refraction profile in a non-solvent under conditions and for a time that enables the non-solvent to permeate the rod and out-diffuse a portion of the additive material, thereby producing the gradient-index polymer rod. The rod produced by the method can be drawn into a graded index polymer fiber. The invention also features a gradient-index polymer rod (or fiber) of condensation-type polymer that is doped with an additive material.

Abstract: A process for producing a light diffusing sheet material, and materials made therefrom. A dispersion of light scattering optically clear particles in an optically clear matrix during mixing of the constituent components of the diffuser in the liquid phase and then forming a film or sheet by, e.g., extrusion or casting, from which a screen suitable for displaying images projected thereupon may be constructed. The respective light dispersing and matrix components are chosen by their respective viscosities, interfacial surface energies, and refractive index differential. In an embodiment, it has been found that when the viscosity ratio of first (matrix) optically clear material to second (light dispersing) optically clear is between 0.05 and 10, the first optically clear material disperses or breaks the second optically clear material up into particles of a desired diameter during mixing or mastication of the two optically clear materials while in the fluid phase.

Abstract: Fiber bow makes mass fusion splicing of optical fiber difficult and this is undesirable. We have found that fiber bow can be significantly reduced if the fiber that is being drawn from a heated optical fiber preform is caused to run through a tubular cooling chamber that extends from the draw furnace, the cooling chamber comprising a tube of inner diameter d.sub.1 <35 mm, preferably <20 mm. In a preferred embodiment the cooling chamber includes an upper cooling chamber of inner diameter d.sub.2 >d.sub.1, with a transition element providing a smooth transition between the two chambers. The cooling chamber desirably is free of turbulence-causing air leaks and/or geometrical features.

Abstract: A method of making an ophthalmic lens including the steps of: preparing a polymerizable composition comprising excessive oxygen content; contacting the polymerizable composition with a gas that is inert or substantially inert to the polymerizable composition, and deoxygenating or partially deoxygenating the polymerizable composition; conveying all or part of the polymerizable composition to an ophthalmic lens mold; polymerizing all or part of the polymerizable composition and obtaining a polymeric ophthalmic lens, and the lens produced by such process.

Abstract: An uncoated lens, especially for use as the lens of a fog light or a headlight for an automobile, and having particularly good resistance against the environmental effects which are inherent in this environment, is formed of a colorless, transparent copolyamide having a glass transition temperature of at least a 170.degree. C., blended with a homopolyamide, and wherein the copolyamide is formed from at least one cycloaliphatic diamine with two cyclohexane rings, and at least one aromatic dicarboxylic acid which is predominantly isophthalic acid. The copolyamide may optionally contain up to 20 mol % of a further polyamide forming monomer of at least one lactam or an omega-aminocarboxylic acid. The homopolyamide is preferably one of PA6, PA11, PA12, PA66, PA69, PA610 or PA612. The cycloaliphatic diamine of the copolyamide is preferably bis(3-methyl-4-aminocyclohexyl)-methane.

Abstract: A rotational indexing base curve deposition array for assembling contact lens base curves and front curves with a prescribed and programmable angular orientation to produce a contact lens having a selected axis placement therein, such as a toric axis for a toric contact lens. An array of front curve molds are arranged in a support pallet with a dosed amount of monomer mixture deposited into each of the front curve molds. An array of deposition tubes, positioned in a support plate and coupled to a vacuum source, is used to pick up and support an array of base curve molds. Each of the deposition tubes is then angularly rotated in to the support plate to a selected angularly indexed position therein. A common angular rotational drive is coupled to each of the deposition tubes in the array to angular index each of the deposition tubes to a precise angular position in the support plate.

Abstract: An object of the present invention is to allow an optical element to be obtained with good precision using a polymer film and a glass substrate as a reinforcer. The present invention is characterized by the fact that a polymer film is formed on a glass substrate which has been treated to prevent the glass substrate and polymer from separation. This allows an optical circuit pattern to be formed without producing separation between the glass substrate and polymer film when the film is formed. The dimensional precision of the configuration of the distributed index in the polymer film can be maintained generally to the same extent as the expansion and shrinkage of the glass substrate. In addition, a vessel obtained with a glass substrate as the bottom surface can be used as the casting vessel.

Abstract: A retroreflective sheeting includes a first array of cube corner element opposing pairs and a second array of cube corner element opposing pairs. The symmetry axes of the cube corner elements in the first and second arrays are tilted in a backward direction at an angle of about 12.degree. to about 30.degree. from an axis normal to a base surface. The second array of cube corner elements is oriented approximately perpendicular to the first array to yield a retroreflective article providing generally uniform total light return about a 360.degree. range of orientation angles and/or a minimum total light return of about 5% across such 360.degree. range. Also disclosed is a mold assembly suitable for use in forming the present retroreflective sheeting and a method of making a retroreflective article using the mold.

Abstract: Unsaturated polyester resin-based compositions that are modified for unexpected improvement in uniform, low optical distortion and/or improved tint speed by the addition of one or more additives selected from an allylic ester and/or an acrylic monomer, together with an exotherm depressant, making the modified polyester resin-based composition commercially viable for casting ophthalmic lenses. The additive(s) and exotherm depressant are useful to modify the polyester for sufficient enhancement of optical distortion and/or tint speed such that any unsaturated polyester resin, capable of producing a clear, low color casting, will be improved sufficiently to provide a composition having the required properties for an ophthalmic lens.

Abstract: Preferential etching techniques are used to form a mold which can then be used to mold a microlens array. A mask (4.sub.i) made of a material which is resistant to a chemical composition for etching the plate is formed on a substrate, so that the mask is in the form of a grid with generally polygonal meshes each centered over one of the desired cells. The sides of each cell of the mask has outgrowths (5.sub.j) extending towards the center of desired cells. The substrate is subjected to the etching composition.

Abstract: The disclosure is a more economical process for producing fibrets of superior quality by directing a dope comprising a cellulose derivative and a suitable solvent therefor into a coagulant and exposing it there to a shearing field to coagulate of the dope and form the fibrets. The fibrets, the solvent and the coagulant are then separated off. The suspension formed from the dope and the coagulant is alternately accelerated and decelerated in the shearing field at least once, preferably at least twice. This makes it possible to maintain a high average degree of turbulence over a long distance, so that a dope of high viscosity can be processed. In the apparatus for producing fibrets, the at least one nozzle (46-49) is disposed within a dispersing facility (40) comprising rotor (44) and stator (43, 45) and further comprising at least two sprockets (50-53), of which at least one sprocket (50) is part of the rotor (44) of the dispersing facility (40).

Abstract: A method of manufacturing complex optical surfaces in soft contact lenses includes a first step of defining the complex optical surfaces with a computer assisted drafting program using a mix of patient determined parameters and selected manufacturing process determined parameters to define a mathematical "meta lens". A machine code data set is then generated to machine a plurality of contact lens mold inserts to define a complex optical surface on each of the inserts. The machining step is conducted with a single point diamond lathe having submicron precision and repeatability. A first and second plurality of intermediate contact lens mold halves are then molded with said contact lens mold inserts to define said complex optical surfaces on said mold halves having micron range transitions between optical surfaces. The complex geometric forms and optical surfaces include bifocal lenses, aspheric lenses, and toric lenses wherein the lenses may include parabolic or elliptical geometry.

Abstract: A collagen containing substrate comprising cattle basal membrane is conditioned by incubating the membranes in a mixture of pepsin, hyaluronidase and acetic acid and separating the collagen from the mixture. The mixture can include pepsin, hyaluronidase and a 0.5M solution of acetic acid in 1:1:10 proportions. The incubation is conducted for about 10 hours at about 45.degree. C. After incubation, collagen is separated from the mixture by centrifuging at a speed of 5000 to 30000 rpms for about 30 minutes. The collagen is mixed with polymerizable monomer and polymerized to form a gel that can be ground to form an intraocular or contact lens.

Abstract: A method for the dewatering of a material layer of paper fibers in a double-screen former, where the sheet weight (oven-dried sheet weight (otro)) is more than 100 g/m.sup.2 and/or the screen circulates with a speed of at least 100 m/min. Two screens are guided at two guide surfaces that, for example, belong to open forming cylinders. In this arrangement forming cylinders of this kind are so dimensioned and positioned that no dewatering elements that contact one of the screens are present between the run-out line of the screens from the first guide surface and the run-in line at the second guide surface.

Abstract: The invention relates to a novel process for the manufacture of mouldings, especially contact lenses, in which a soluble prepolymer comprising crosslinkable groups is crosslinked in solution, and also to mouldings, especially contact lenses, obtainable in accordance with that process. The present invention relates also to novel prepolymers that can be used in the process according to the invention, especially derivatives of a polyvinyl alcohol having a molecular weight of at least about 2000 that, based on the number of hydroxy groups of the polyvinyl alcohol, comprise from approximately 0.5 to approximately 80% of units of formula I ##STR1## wherein R is lower alkylene having up to 8 carbon atoms,R.sup.1 is hydrogen or lower alkyl andR.sup.

Abstract: An apparatus for separating individual contact lens mold assemblies, the assemblies each being a front curve mold half and a back curve mold half, each mold half having annular circumferential flanges, is included. The apparatus includes a device for applying steam to the back curve mold half to form a temperature gradient from the front mold half to the back mold half. The apparatus also includes a second device to pry the mold halves apart.