Described herein is a method for producing photochromic silicone hydrogel contact lenses in a relatively efficient and consistent manner from a polymerizable composition under a controlled thermal curing scheme. The main polymerizable components in the polymerizable composition are a high radical-reactive hydrophilic (meth)acrylamido monomer, a high radical-reactive siloxane-containing (meth)acrylamido monomer, and a polysiloxane vinylic crosslinker(s) free of low-reactive ethylenically unsaturated group as the main crosslinker. The thermal free radical initiator having a 10 hour half-life temperature (T10hλ) of from about 50° C. to about 90° C. The controlled thermal curing scheme includes maintaining a first curing temperature of from about (T10hλ−20)° C. to about T10hλ° C. for a first curing time and maintaining a second curing temperature of from about (T10hλ+10)° C. to about (T10hλ+35)° C. for a second curing time.