An air cleaning apparatus that includes a housing, a fan, an ultraviolet lamp, and a cylindrical filter. In the standard wearing position in which a horizontal line connects the center of the pupil of the eye to an area of the ear on which an earpiece of the frame rests, the optical axis defined by the line passing through the two centers of the spherical surfaces makes an angle of at least 10 with a horizontal axis. The pawls on the driving member engage outwardly concentric notches on the driven member, and are activated and deactivated by inner reversing cams of the reversing ring. If the controller accepts the decision to use the viewfinder, the display section displays no subject’s image, and displays information about the degree of focusing of the subject’s image for at least a certain period of time. Wherein the implantable circuit and the antenna have an internal resonant frequency mismatched from an external resonant frequency of an external circuit, to account for resonance frequency variation as a result of implantation in the subject’s body. This can be conceptualized as \u201cavoiding at all costs\u201d delivering false shocks, even at the expense of failing to deliver a shock to a treatable ventricular tachyarrhythmia.