An environmentally-sealed refractive lighting optic includes a single light-emitting diode (LED) printed circuit card that includes a plurality of LED components and a single, refractive optic element retained directly to the LED printed circuit card in a self-sealing manner without mechanical fasteners. The refractive optic element is configured to environmentally seal the LED components on the LED printed circuit card. Further, the refractive optic element may include a liquid silicone rubber material or an optically-clear low-pressure molded room temperature vulcanizing (RTV) silicone material.