| 摘要 |
<p>Plastic multifocal or progressive lenses are formed from preformed lenses (11) with predetermined lens corrections at the optical centers. A preformed lens is placed against a mold (13) such that the surfaces of the preformed lens and the mold form a cavity (14). A resin composition fills the cavity and is curved to form an optical segment (12). The cavity (14) is shaped to correspond to a desired change in curvature such that the correction at the optical center is the same as the predetermined lens correction at the optical center of the preformed lens (11). The preformed lens (11) may be cast with a thin non-prescription carrier layer (16) for the multifocal or progressive region of the finished lens. The methods allow casting of lenses without the use of conventional gaskets.</p> |
