| 摘要 |
Apparatus (20) is provided including a frame (24) worn on a face of a subject, such that a portion of the frame is located in front of a first eye of the subject and not in front of a second eye. A first lens system coupled to the portion of the frame comprises one or more first lenses (22). A second lens system (26) is coupled to the portion of the frame, the second lens system comprising one or more second lenses (40 and 42). A transparency regulation element (30) coupled to the first lens system has variable transparency, and enhances viewing through the second lens system. A power unit (28) is coupled to the frame, and, during a first period, drives the transparency regulation element to darken the first lens system without substantially darkening at least a portion of the second lens system, and during a second period, the power unit does not drive the transparency regulation element to substantially darken the first lens system. Other embodiments are also described. |
