A method for injection molding of a plus power lens element having an edge thickness of at most 0.5 mm and a center thickness of at least 1.3 mm, comprising: providing two facing mold inserts, injecting a melt of thermoplastic material comprising at least one UV absorber at an injection speed greater than 50 mm/s at a temperature higher than a glass transition temperature (Tg) of said thermoplastic material in an initial molding cavity delimited by said two facing mold inserts, wherein the thermoplastic material comprises a high flow polycarbonate resin having a weight average molecular weight of less than 26,000 and a melt flow rate at 300°C/1.2kg of at least 15 cm 3 /10 min per ISO 1133; during said injecting, moving said two facing mold inserts toward one another to define a final molding cavity whose volume is less than that of said initial molding cavity; and after cooling and opening of the molding cavity, recovering said plus power lens element ; wherein one of said two facing mold inserts comprises a flat surface facing said initial molding cavity, thereby to form a flat surface on one side of said plus power lens element , wherein the other of said two facing mold inserts comprises a concave surface facing the initial molding cavity, thereby to form a convex surface on an opposite side of the plus power lens element , and wherein said moving of the two facing mold inserts toward one another is effected at a speed of greater than 100 mm/s, wherein an edge distance between said two facing mold inserts when delimiting said initial molding cavity is not more than 2.5 times an edge thickness of the plus power lens element , wherein the flat surface of the one of the two facing mold inserts has less than 20 fringes as indicated by flatness measurements using interference fringes of monochromatic light. providing two facing mold inserts, injecting a melt of thermoplastic material comprising at least one UV absorber at an injection speed greater than 50 mm/s at a temperature higher than a glass transition temperature (Tg) of said thermoplastic material in an initial molding cavity delimited by said two facing mold inserts, wherein the thermoplastic material comprises a high flow polycarbonate resin having a weight average molecular weight of less than 26,000 and a melt flow rate at 300°C/1.2kg of at least 15 cm 3 /10 min per ISO 1133; during said injecting, moving said two facing mold inserts toward one another to define a final molding cavity whose volume is less than that of said initial molding cavity; and after cooling and opening of the molding cavity, recovering said plus power lens element ; wherein one of said two facing mold inserts comprises a flat surface facing said initial molding cavity, thereby to form a flat surface on one side of said plus power lens element , wherein the other of said two facing mold inserts comprises a concave surface facing the initial molding cavity, thereby to form a convex surface on an opposite side of the plus power lens element , and wherein said moving of the two facing mold inserts toward one another is effected at a speed of greater than 100 mm/s, wherein an edge distance between said two facing mold inserts when delimiting said initial molding cavity is not more than 2.5 times an edge thickness of the plus power lens element , wherein the flat surface of the one of the two facing mold inserts has less than 20 fringes as indicated by flatness measurements using interference fringes of monochromatic light. <EOS>