A device including a frame that has first and second openings and a pair of temple arms that pivot relative to the frame. The device includes an imaging unit connected to the frame at a location adjacent to the first opening and capture images through the first opening. The device includes a mechanical switch disposed on the frame or the imaging unit adjacent to the first opening. The device includes lenses fitted within the first and second openings, and the lens that fits within the first opening includes a key interfaceable with the mechanical switch and configured to adjust firmware of the imaging unit based on physical features of the lenses upon interface with the mechanical switch.