(under subclass 168) Subject matter wherein multifocal lenses have portions of three or more focal powers respectively, for example, for near, intermediate and far vision.
(1) Note. The above noted lenses may have countersinks and segments of different refractive powers fused therein, or the lenses may be formed of one piece of glass and by grinding away the near vision and intermediate vision portions. The countersinks and segments as well as the ground-away lens portions in the one piece lenses may be of different dimensions and shapes.
SEE OR SEARCH THIS CLASS, SUBCLASS:
172, for multifocal lenses with long vision and reading sections having joined lens elements, and 168 for such lenses made from a single piece of glass.
