| 摘要 |
An optical element for use in power adjustable spectacles comprises a front lens and a back lens which can slide laterally with respect to each other to achieve a first relative position and a second relative position. The optical element may be designed to provide good optical performance for far-distance viewing and for near-distance viewing, or to provide good optical performance for near-distance viewing and for intermediate-distance viewing. In some cases, the front lens and the back lens can slide laterally with respect to each other to achieve a third relative position, and the optical element may be designed to provide good optical performance for far-distance viewing, for intermediate-distance viewing and for near-distance viewing. In all cases, the predetermined addition of the prescription is in the range of 0.50 diopters to 3.00 diopters. |
