Patent ID: 7472993

Claim:
A bifocal plastic lens comprising a small lens for short-range view, wherein a preparatory lens member having the small lens protruded on a convex surface side is molded from a resin comprising an episulfide resin having a refractive index of not smaller than 1.66 (nd) and another resin having a lower refractive index compared with the preparatory lens member is cast and cured so as to adhere to the surface provided wit the small lens of the preparatory lens member and to be integrated with the preparatory lens member, resulting in that all over the surface provided with the small lens is covered by the resin having lower refractive index and the small lens is incorporated into the resulting bifocal lens in such a manner that the small lens does not cause a protrusion to form on any external surface of the resulting bifocal lens, a concave surface side of the preparatory lens member is employed as a surface having a corrective refractive power, and the bifocal plastic lens having an interface between the convex surface of the prepatory lens and the resin adhered to the convex surface of the preparatory lens wherein at least a part of the interface by a peripheral edge portion of the small lens is chamfered with a curved surface having a curvature lower than the curvature by portions of the small lens other than the peripheral edge portion in order to prevent the edge of the small lens from being conspicuous.