Students racing over curving roads in a video-game simulation hope to help scientists at Rensselaer Polytechnic Institute's Lighting Research Center (LRC) answer a serious question: Do current lighting standards mislead us about the efficiency of roadway, parking lot, and security lighting? Lighting efficiency is widely calculated as lumens per watt of energy, explains Mark Rea, LRC director. The lumen, a measurement defined in the 1920s, is based on the response in bright light of the fovea, the part of the retina that contains cone photoreceptors. It's responsible for central, high-acuity vision. However, parts of the retina containing rod-shaped photoreceptors also are important in low-light conditions and for peripheral vision. As a result, lumens per watt delivers an accurate efficiency measure for tasks done in bright light, but is less accurate for such tasks as night driving, which requires good peripheral vision in low light. In research sponsored jointly by General Electric, OSRAM Sylvania, Philips, and the Department of Energy, the LRC is conducting experiments with the driving simulator to measure the reaction of the participants under varying lighting conditions. The information gained could help industry produce new lighting systems that are more efficient, Rea believes, since they would take into account the complex responses of the human eye. Phone Rea at (518) 276-8701 (E)
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