A method for producing photochromic contact lenses, comprising the steps of: providing a mold for making a contact lens, wherein the mold has a first mold half with a first molding surface defining the anterior surface of a contact lens and a second mold half with a second molding surface defining the posterior surface of the contact lens, wherein said first and second mold halves are configured to receive each other such that a cavity is formed between said first and second molding surfaces; introducing a polymerizable composition into the cavity, wherein the polymerizable composition comprises (a) at least one hydrophilic (meth)acrylamido monomer, (b) at least one siloxane-containing (meth)acrylamido monomer, (c) at least one polysiloxane vinylic crosslinker, wherein all ethyleneically unsaturated groups of said at least one polysiloxane vinylic crosslinker are (meth)acrylamido groups, (meth)acryloxy groups, vinyloxycarbonyl-amino groups, vinyloxycarbonyloxy groups, or combinations thereof, (d) at least one photochromic compound, (e) at least one thermal free radical initiator having a 10-hour half-life temperature (designated as T 10hλ) of from 50°C to 90°C, and (f) from 4% to 20% by weight of an organic solvent relative to the total weight of the polymerizable composition, wherein the sum of the amounts of components (a) to (c) is at least 90% by weight relative to total amount of all polymerizable components in the polymerizable composition; curing thermally the polymerizable composition in the lens mold in an oven to form an unprocessed photochromic silicone hydrogel lens precursor, wherein the step of curing thermally comprises (a) maintaining a first curing temperature of from (T 10hλ - 20)°C to T 10hλ °C for a first curing time, (b) maintaining a second curing temperature of from (T 10hλ + 10)°C to (T 10hλ + 35)°C for a second curing time, and (c) optionally maintaining a third curing temperature of 100°C for a third curing time; and subjecting the unprocessed photochromic silicone hydrogel lens precursor to one or more post-molding processes selected from the group consisting of extraction, surface treatment, hydration, packaging, sterilization, and combinations thereof, to form a photochromic silicone hydrogel contact lens. providing a mold for making a contact lens, wherein the mold has a first mold half with a first molding surface defining the anterior surface of a contact lens and a second mold half with a second molding surface defining the posterior surface of the contact lens, wherein said first and second mold halves are configured to receive each other such that a cavity is formed between said first and second molding surfaces; introducing a polymerizable composition into the cavity, wherein the polymerizable composition comprises (a) at least one hydrophilic (meth)acrylamido monomer, (b) at least one siloxane-containing (meth)acrylamido monomer, (c) at least one polysiloxane vinylic crosslinker, wherein all ethyleneically unsaturated groups of said at least one polysiloxane vinylic crosslinker are (meth)acrylamido groups, (meth)acryloxy groups, vinyloxycarbonyl-amino groups, vinyloxycarbonyloxy groups, or combinations thereof, (d) at least one photochromic compound, (e) at least one thermal free radical initiator having a 10-hour half-life temperature (designated as T 10hλ) of from 50°C to 90°C, and (f) from 4% to 20% by weight of an organic solvent relative to the total weight of the polymerizable composition, wherein the sum of the amounts of components (a) to (c) is at least 90% by weight relative to total amount of all polymerizable components in the polymerizable composition; (a) at least one hydrophilic (meth)acrylamido monomer, (b) at least one siloxane-containing (meth)acrylamido monomer, (c) at least one polysiloxane vinylic crosslinker, wherein all ethyleneically unsaturated groups of said at least one polysiloxane vinylic crosslinker are (meth)acrylamido groups, (meth)acryloxy groups, vinyloxycarbonyl-amino groups, vinyloxycarbonyloxy groups, or combinations thereof, (d) at least one photochromic compound, (e) at least one thermal free radical initiator having a 10-hour half-life temperature (designated as T 10hλ) of from 50°C to 90°C, and (f) from 4% to 20% by weight of an organic solvent relative to the total weight of the polymerizable composition, curing thermally the polymerizable composition in the lens mold in an oven to form an unprocessed photochromic silicone hydrogel lens precursor, wherein the step of curing thermally comprises (a) maintaining a first curing temperature of from (T 10hλ - 20)°C to T 10hλ °C for a first curing time, (b) maintaining a second curing temperature of from (T 10hλ + 10)°C to (T 10hλ + 35)°C for a second curing time, and (c) optionally maintaining a third curing temperature of 100°C for a third curing time; and (a) maintaining a first curing temperature of from (T 10hλ - 20)°C to T 10hλ °C for a first curing time, (b) maintaining a second curing temperature of from (T 10hλ + 10)°C to (T 10hλ + 35)°C for a second curing time, and (c) optionally maintaining a third curing temperature of 100°C for a third curing time; and subjecting the unprocessed photochromic silicone hydrogel lens precursor to one or more post-molding processes selected from the group consisting of extraction, surface treatment, hydration, packaging, sterilization, and combinations thereof, to form a photochromic silicone hydrogel contact lens.