Sandwiched colored hydrogel contact lenses

A method for producing sandwiched colored hydrogel contact lenses, comprising the steps of:

• (1) obtaining a male mold half, a first female mold half and a second female mold half, wherein the male mold half has a first molding surface defining the posterior surface of a contact lens to be molded, wherein the first female mold half has a second molding surface defining the front surface of a donut shape layer 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 male mold half and the first female mold half are configured to receive each other such that an donut shape layer-molding cavity is formed between the second molding surface and a donut shape layer portion of the first molding surface when the male mold half is closed with the first female 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 first and third molding surfaces when the second female mold half is closed with the male mold half;
• (2) dispensing an amount of a donut shape layer-forming composition on the second molding surface of the first female mold half;
• (3) placing the male mold half on top of the donut shape layer-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 donut shape layer-forming composition within the donut shape layer-molding cavity;
• (4) curing the donut shape layer-forming composition in the donut shape layer-molding cavity of the first molding assembly to form a molded donut shape-layer;
• (5) separating the first molding assembly obtained in step (4) into the male mold half and the first female mold half with the molded donut shape layer that is adhered onto the first molding surface;
• (6) printing at least one colored cosmetic pattern onto the molded donut shape layer;
• (7) optionally curing the colored cosmetic pattern on the molded donut shape layer;
• (8) dispensing a bulk lens-forming composition in the second female mold half with the printed molded donut shape layer adhered thereon in an amount sufficient for filling the lens-molding cavity, wherein the donut shape layer-forming composition is same or different from the bulk lens-forming composition;
• (9) placing the male mold half on top of the lens-forming composition in the second female mold half and closing the male mold half and the second female mold half to form a second molding assembly comprising the bulk lens-forming composition and the molded donut shape-layer immersed therein in the lens-molding cavity;
• (10) curing the bulk lens-forming composition in the lens-molding cavity of the second molding assembly to form an embedded contact lens that comprises the cosmetic iris pattern covered by the bulk lens-forming composition and donut shape-layer forming material, wherein the donut shape layer has a thickness larger than 10 μm,
• (11) separating the second molding assembly obtained in step (10) into the male mold half and the second female mold half, with the embedded hydrogel contact lens adhered on a lens-adhered mold half which is one of the male and second female mold halves;
• (12) removing the embedded hydrogel contact lens from the lens-adhered mold half.