An objective lens for converging light onto an information recording medium includes a refracting interface for converging an incident light into a convergent light, and a refractive index varying member disposed between the refracting interface and the information recording medium, and having a refractive index that is varied according to an externally applied voltage. The system may include a display device with at least one input device. A Xe proportion of the discharge-gas mixture is in a range of from 2% to 20%, a He proportion of the discharge-gas mixture is in a range of from 15% to 50%, the He proportion is greater than the Xe proportion, and a total pressure of the discharge-gas mixture is in a range of from 400 Torr to 550 Torr. A data transceiver wirelessly transmits the information to the base unit.