A greater efficiency and cost-effectiveness is achieved by optically assessing the condition of a gas discharge lamp. Herein, a system and method of optically assessing lamp condition includes measuring the intensity of emitted light within two portions of the emitted spectrum. One portion of the lamp's spectrum is selected such that the intensity of emitted light from that portion remains relatively constant as the lamp ages. The second portion of the lamp's spectrum is selected such that the intensity of the emitted light varies measurably as the lamp ages. A ratio is computed between the two intensities. Comparing this ratio to a reference ratio provides information of the relative present condition (i.e., age) of the lamp being tested. Associating the lamp with location data is a further aspect. Important advantages are the ability to predict relative lamp age, and thus avoid both premature lamp replacement and pre-failure lamp cycling.