Abstract: A method of continuously fabricating a lens excellent in various optical characteristics and having no nonuniformity in the characteristics over a total of the lens and a lens fabricated by the method. A first step for forming thiourethane prepolymer and a second step for making thiourethane prepolymer react with at least one urethane forming monomer are carried out in an extruder or in a reactor having an extruding device at a succeeding step, extruded thermoplastic thiourethane-urethane copolymer for optical use is elongated in a sheet-like shape, a lens precursor is formed by punching out the copolymer elongated in a sheet-like shape and the lens precursor is pressed such that a predetermined curved face is provided at least on one face of the lens precursor.

Abstract: As a method by which failed products of hard-coated plastic lenses, especially hard-coated high-refractive-index plastic lenses can be regenerated to be in a re-usable condition, plastic lenses coated with a hard coat consisting essentially of an organopolysiloxane compound and an inorganic oxide, are contacted with an aqueous solution of a silicate and/or a phosphate. For example, an aqueous solution of 30% trisodium phosphate heated at 50° C. is sprayed over hard-coated plastic lenses for 5 minutes. The hard coat is removed from the lenses, while the surface of the coat-removed lenses is not roughed. The coat-removed lenses are re-usable.

Abstract: The present invention provides a method of manufacturing plastic lenses of urethane type resin having no or very little optical strain by the casting polymerization method. In the casting polymerization process, polymerization is effected while a suitable motion, for example, a particular rotative motion, or a motion based on rotation with the rotatable shaft disposedhorizontal is imparted to the shell to change the direction of the gravity acting on any minute portion of a monomer injected into the shell.