A goggle includes a lens assembly which comprises a front lens, a rear lens spaced apart from the front lens, and a liquid crystal device disposed on one of the lenses. The goggle includes a frame, which defines an aperture and a peripheral channel. The peripheral channel receives the front lens and the rear lens is positioned rearward of the channel so that the aperture receives the lens assembly. A power unit includes a battery and a drive circuit, wherein the drive circuit is connected to a pair of prongs that are electrically connectable to the liquid crystal device for operation thereof. The power unit provides a master switch connected to the battery to control application of power to the drive circuit, and a state change switch to control application of power from the drive circuit, through the prongs, to the liquid crystal device.