MANUFACTURE OF REFRACTIVE INDEX DISTRIBUTION TYPE PLASTIC LENS

摘要

PROBLEM TO BE SOLVED: To stably form a desired refractive index distribution form by a gelling method for manufacturing a multifocal type refractive index distribution type plastic lens required for a presbyopia contact lens or the like. SOLUTION: A method for manufacturing a refractive index distribution type plastic lens comprises the step of manufacturing a gel of a polymerizable monomer for giving a matrix polymer, and the step of diffusing a substance for forming a refractive index distribution on the gal obtained by the manufacture of the gel in such a manner that the diffusing is conducted under the condition that polymerizing reaction is proceeded in the monomer of the gel. With this condition, the lens can be stably formed even with the refractive index distribution in which a refractive index distribution coefficientαis 3 or above.