a method of producing a dioptric photochromic semi - finished lens , a diopter of which is to be imparted by grinding a concave surface of the semi - finished lens . color concentration between a center portion and a peripheral portion is maintained at a fixed color concentration independent of the diopter of the lens and the lens is shockproof . in the method , after mixing a photochromic material with a thermoplastic polycarbonate resin to make a sheet , the sheet is processed to have a spherical surface sheet , set in a mold and thermoplastic polycarbonate resin is injected in the mold to be bonded with the sheet .