A lighting system enables the lights within the ceiling of a clean room to be serviced and maintained without compromising the clean room and without disturbing the hermetic seals between the clean room and the ceiling grid. The lighting system includes a light transmissible lens hermetically sealed to one or more tracks of the ceiling grid system on the first upward side of a portion of the tracks so as to inhibit particles from passing between tracks and the lens. A light fixture may also be hermetically sealed to a first upward surface of the lens so as to inhibit particles from passing between the lens and the light fixture.