A lighting device is provided which comprises an optically non-opaque wall consisting essentially of a polymeric material and defining a portion of an envelope; a light source sealed within the envelope at a pressure of less than one atmosphere absolute; and an electrical driving device in electrical communication with the light source for causing the light source to generate light. According to another aspect of the invention, a lighting device is provided which comprises an optically non-opaque wall consisting essentially of a polymeric material and defining a portion of an envelope; a gas disposed and sealed within the envelope at a pressure of less than one atmosphere absolute, the wall being substantially impermeable by the gas; and an electrical driving device in at least one of electrical and electromagnetic communication with the gas for activating the gas to generate light. Related methods also are disclosed. In the various devices and methods, the polymeric wall material comprises a polycarbonate material, and may consist of or consist essentially of a polycarbonate material. Electrode housings and connectors also are disclosed.