| 摘要 |
Plastic bifocal lenses partic. aspherical cateract lenses prodn A cylindrical opening is drilled in a lens blank, a filler piece is set into the opening with a recessed radius on the inside to accept the near vision lens, the opening is filled with a plastic monomer and after applying the near vision lens and the filler piece, and removal of excess monomer, the lens blank, filler and near lens are polymerised to form one optical unit which can be ground to the required optical surface finish. |
