| 摘要 |
The composite plastic lens includes an anterior plastic lens having a first corrective feature and a posterior plastic lens having a second corrective feature. One of the lenses, preferably the anterior lens, may have an optical center axis that is decentered with respect to the geometric center axis of the lens. That lens is prism-shaped. Both lenses are disposed atop one another such that when their optical center axes are combined, the resultant optical center axis or principal axis of the composite lens is at a predetermined position relative to the bifocal, multifocal or progressive lens feature carried by the anterior lens. The anterior and posterior lenses are joined together by an adhesive that bonds opposing, etched surfaces of those lenses. The method of making the composite plastic lens includes, in one embodiment, the steps of etching the front and rear surfaces of the posterior and anterior lenses and bonding those etched surfaces together with an adhesive. The adhesive is placed between the lenses while the lenses are angularly disposed with respect to the horizontal. Thereafter, the lenses are floated on a heated fluid to cure the adhesive. By heating the lenses prior to bonding, the posterior and anterior lenses return to their original shape and curvature. |
