| 摘要 |
<p>A bifocal plastic lens, comprising a basic lens and a small lens with different refractive powers, wherein a small lens portion is not projected and a boundary surface between the basic lens and the small lens is hard to observe. A base lens member including the small lens or a base lens member including a recessed part forming a molded small lens surface is preliminarily molded and another resin is fitted to the base lens member and hardened to form them integrally with each other so that the small lens is taken in the lens and a projected face is not formed by the small lens. The small lens or a molded portion including the small lens is formed of a resin with a refractive index higher than that of the resin forming the other portions. To make less inconspicuous the boundary surface between the small lens and the basic lens, the thickness of the small lens at the peripheral edge is reduced to generally zero in the boundary surface, a part of the boundary surface in the thickness direction of the lens is formed in curved surface, or a reflection reduction means such as coloring and matting is applied to a height difference in the boundary surface.</p> |
