Abstract: The invention provides a multifocal ophthalmic lens that is a hybrid lens in that it combines both soft lens material and rigid lens material. The lens is more comfortable to wear than a rigid lens and yet it provides correction for astigmatism without the need for the addition of cylinder power.

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 apparatus for causing the polymerized excess monomer to separate from a molded lens by increasing the surface energy of the flange area of one mold piece, causing the polymerized excess monomer to stick thereto. Specifically when manufactured under inert atmosphere conditions, a particular manifold is needed to supply an oxygen bearing gas, air, to the area to be treated while preventing the oxygen from contaminating the lens manufacturing area of the molds or diluting the nitrogen atmosphere of other lens process areas. It has been found that generation of the ionized oxygen by means of a corona treatment electrode sufficiently increases the adherence of the polymer to the mold piece so treated.

Abstract: An apparatus and method for causing the polymerized excess monomer to separate from a molded lens by increasing the surface energy of the flange area of one mold piece, causing the polymerized excess monomer to stick thereto. Specifically when manufactured under inert atmosphere conditions, a particular manifold is needed to supply an oxygen bearing gas, air, to the area to be treated while preventing the oxygen from contaminating the lens manufacturing area of the molds or diluting the nitrogen atmosphere of other lens process areas. It has been found that generation of the ionized oxygen by means of a corona treatment electrode sufficiently increases the adherence of the polymer to the mold piece so treated.

Abstract: An apparatus and method for directing accelerated electrons to at least part of one surface of one ophthalmic mold piece prior to filling with monomer and lens polymerization. In particular it has been found that generation of the ionized oxygen by means of a corona treatment electrode sufficiently increases the adherence of the polymer to the mold piece so treated. In the preferred embodiment, the flange around the convex, male piece of the lens mold is corona treated so that when the mold pieces are separated after lens polymerization, the flashing of excess polymerized material surrounding the lens cavity adheres to that male, convex piece flange while the lens is removed with the female, concave piece.

Abstract: An apparatus and method for directing accelerated electrons to at least part of one surface of one ophthalmic mold piece prior to filling with monomer and lens polymerization. In particular it has been found that generation of the ionized oxygen by means of a corona treatment electrode sufficiently increases the adherence of the polymer to the mold piece so treated. In the preferred embodiment, the flange around the convex, male piece of the lens mold is corona treated so that when the mold pieces are separated after lens polymerization, the flashing of excess polymerized material surrounding the lens cavity adheres to that male, convex piece flange while the lens is removed with the female, concave piece.

Abstract: An improved method is disclosed of imparting a tint or color to a soft, hydrogel contact lens by uniformly dispersing a dye throughout the lens. The dye is composed of a water-soluble compound essentially free of ethylenic unsaturation. A homogeneous solution of the dye in a hydrophilic monomer is prepared, the solution is subjected to polymerization conditions to yield a hydrophilic polymer from which the lens is formed, and the dye dispersed within the polymer is bonded to the polymer by contact with aqueous base prior to final hydration.The finished lens does not require soaking in an aqueous solution of the dye to impart the desired tint or color to the lens. Additionally, the dye uniformly dispersed throughout the lens according to the improved method does not leach out of the lens or migrate within the lens.

Abstract: Shaped hydrogel articles such as soft contact lenses are prepared by (1) molding or casting a polymerization mixture comprising: (a) a monomer mixture comprising a major proportion of a hydrophilic (meth)acrylate ester such as 2-hydroxyethyl methacrylate, an alkyl (meth)acrylate wherein the alkyl group contains at least four carbon atoms, and a cross-linking monomer; and (b) a water-displaceable diluent, wherein said diluent has a viscosity of at least 100 MPa Sec at 30.degree. C., and wherein said diluent consists essentially of a boric acid ester of certain dihydric alcohols, said dihydric alcohols having Hansen polar (w.sub.p) and Hansen hydrogen bonding (w.sub.h) cohesion parameters falling within the area of a circle defined as having a center at w.sub.h =20.5, w.sub.p =13, and a radius of 8.5, to produce a shaped gel of a copolymer of said monomers and said diluent, and (2) thereafter replacing said diluent with water.

Abstract: Shaped hydrogel articles such as soft contact lenses are prepared by (1) molding or casting a polymerization mixture comprising: (a) a monomer mixture comprising a major proportion of a hydrophilic (meth)acrylate ester such as 2-hydroxyethyl methacrylate, and a cross-linking monomer; and (b) a water-displaceable diluent, wherein said diluent has a viscosity of at least 100 MPa Sec at 30.degree. C., and wherein said diluent consists essentially of a boric acid ester of certain dihydric alcohols, said dihydric alcohols having Hansen polar (.delta..sub.p) and Hansen hydrogen bonding (.delta..sub.h) cohesion parameters falling within the area of a circle defined as having a center at .delta..sub.h =20.5, .delta..sub.p =13, and a radius of 8.5, to produce a shaped gel of a coploymer of said monomers and said diluent, and (2) thereafter replacing said diluent with water.