Patent ID: 7452067

Claim:
Apparatus comprising: a frame configured to be 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 of the subject; a first lens system coupled to the portion of the frame, the first lens system comprising one or more first lenses; a second lens system coupled to the portion of the frame, the second lens system comprising one or more second lenses; a transparency regulation element coupled to the first lens system, the transparency regulation element having variable transparency, and configured to enhance viewing through the second lens system; and a power unit coupled to the frame, configured to: during a first period, drive 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 after the first period, not drive the transparency regulation element to darken the first lens system.