Abstract: A liquid lens that includes a first window, a second window, and a cavity disposed between the first window and the second window; a first and second liquid disposed within the cavity, the first and second liquid substantially immiscible with each other and having different refractive indices such that an interface between the first and second liquid defines a variable lens, at least a portion of the first liquid disposed within a first portion of the cavity, the second liquid disposed within a second portion of the cavity; a common electrode in electrical communication with the first liquid; and a driving electrode disposed on a sidewall of the cavity and insulated from the first liquid and the second liquid by an insulating element, wherein the insulating element comprises an insulating outer layer in contact with the liquids, the insulating outer layer comprising a lanthanide series oxide.