A composite face seal having an annular seal rotor with a metal base portion and a radially extending flange. A resistance element having a predetermined resistance value is provided between the power source portion and the unselected first and second wirings. The converter unit determines when to draw power from an external power and when to cease drawing power from the external power source by detecting a power enablement condition or a power disablement condition. Certain embodiments provide correction of the subject’s near and far vision.