Method for making embedded silicone hydrogel contact lenses

A method for producing embedded SiHy contact lenses, comprising the steps of:

• (1) obtaining a first female mold half, a male mold half and a second female mold half, wherein the first female mold half has a first molding surface defining the front surface of an insert to be molded, wherein the male mold half has a second molding surface defining the posterior surface of a contact lens to be molded and also the back surface of the insert to be molded, wherein the second female mold half has a third molding surface defining the anterior surface of the contact lens to be molded, wherein the first female mold half and the male mold half are configured to receive each other such that an insert-molding cavity is formed between the first molding surface and a central portion of the second molding surface when the first female mold half is closed with the male mold half, wherein the second female mold half and the male mold half are configured to receive each other such that a lens-molding cavity is formed between the second and third molding surfaces when the second female mold half is closed with the male mold half;
• (2) dispensing an amount of an insert-forming composition in the first female mold half;
• (3) placing the male mold half on top of the insert-forming composition in the first female mold half and closing the male mold half and the first female mold half to form a first molding assembly comprising the insert-forming composition within the insert-molding cavity;
• (4) curing the insert-forming composition in the insert-molding cavity of the first molding assembly to form a molded insert made of a crosslinked polymeric material formed from the insert-forming composition;
• (5) separating the first molding assembly obtained in step (4) into the first female mold half and the male mold half with the molded insert that is adhered onto the central portion of the second molding surface;
• (6) dispensing a lens-forming composition in the second female mold half in an amount sufficient for filling the lens-molding cavity, wherein the lens-forming composition comprises (a) at least one N,N-dialkylacrylamide having a 1-octanol-water partition coefficient Log(POW) of from about 0.7 to about 2.1, (b) at least one hydrophilic (meth)acrylamido monomer having a Log(POW) of less than about 0.5, (c) at least one polysiloxane acrylic crosslinker, (d) at least one photoinitiator, and (e) at least one non-reactive diluent, wherein the lens-forming composition is free of siloxane-containing vinylic monomer having a tris(trialkylsilyloxy)silyl or bis(trialkylsilyloxy)silyl group or a polysiloxane segment having 3 to 15 consecutive siloxane units, wherein the sum of the amounts of components (a) to (d) is at least 90% by weight relative to total amount of all polymerizable components in the polymerizable composition;
• (7) placing the male mold half with the molded insert that is adhered onto the central portion of the second molding surface on top of the lens-forming composition in the second female mold half and closing the second female mold half and the male mold half to form a second molding assembly comprising the lens-forming composition and the molded insert immersed therein in the lens-molding cavity;
• (8) actinically curing the lens-forming composition in the lens-molding cavity of the second molding assembly to form an embedded SiHy contact lens precursor that comprise a bulk SiHy material formed from the lens-forming composition and the insert embedded in the bulk material;
• (9) separating the second molding assembly obtained in step (8) into the second female mold half and the male mold half, with the embedded SiHy contact lens precursor adhered on a lens-adhered mold half which is one of the second female mold half and the male mold halves;
• (10) removing the embedded SiHy contact lens precursor from the lens-adhered mold half;
• and
• (11) subjecting the embedded SiHy contact lens precursor to post-molding processes including one or more processes selected from the group consisting of extraction, hydration, surface treatment, packaging, sterilization, and combinations thereof to obtain an embedded SiHy contact lens.

An embedded SiHy contact lens, comprising a lens body that comprises an anterior surface, an opposite posterior surface, a bulk hydrogel material having a first refractive index, and a circular insert embedded in the bulk hydrogel material, wherein the circular insert has a diameter of about 11.0 mm or less and is made of a crosslinked polymeric material having a second refractive index, wherein the circular insert has a front surface and an opposite back surface and is located in a central portion of the embedded SiHy contact lens and concentric with a central axis of the lens body, wherein one of the front and back surfaces of the circular insert merges with one of the anterior and posterior surface of the lens body while the other one of the front and back surfaces of the circular insert is buried within the bulk hydrogel material and designated as buried surface, wherein the buried surface of the circular insert comprises a diffractive structure, wherein the bulk SiHy material comprises at least 92% by weight of repeating units of (a) at least one N,N-dialkylacrylamido monomer which has a 1-octanol-water partition coefficient Log(POW) of from about 0.7 to about 2.1, (b) at least one hydrophilic (meth)acrylamido monomer having a Log(POW) of less than about 0.5, and (c) of at least one polysiloxane acrylic crosslinker, wherein the second refractive index is at least 0.03 higher than the first refractive index, wherein the crosslinked polymeric material comprising repeating units of at least one aryl vinylic monomer and at least one aryl vinylic crosslinker.