Plastic lenses are lightweight, highly tough and easy to be dyed. Properties particularly required for plastic lenses are: low specific gravity; high transparency; low yellowness; high refractive index and high Abbe number as optical properties; high heat resistance; high strength; and the like. A high refractive index allows a lens to be thinner, and a high Abbe number reduces the chromatic aberration of a lens.
Recently, many examples using an organic compound having a sulfur atom for providing a high refractive index and a high Abbe number have been reported. Among such examples, polyepisulfide compounds having a sulfur atom are known to provide a good balance between the refractive index and the Abbe number (Patent Document 1). Further, since polyepisulfide compounds can be reacted with various compounds, for the purpose of the improvement of physical properties, compositions in combination with various compounds have been proposed (Patent Documents 2-5).
However, there is a case where it is difficult to dye a lens produced from an episulfide compound according to a method generally used for plastic lenses, and sometimes required characteristics of spectacle lenses in which importance is placed on design property are not sufficiently achieved. Further, in the case of powerful lenses, there is a case where a lens is broken at the time of demolding due to poor mold release characteristics, or there is a case where required surface accuracy cannot be obtained because a lens is released from a mold during polymerization due to excessively high mold release characteristics.