The impact of LED on human visual experience

High flexibility of LED offers possibility to adjust parameters of lighting, like CCT (correlated color temperature), luminance, and spectral power distribution so that lighting can be made to have positive effects on people. This experiment investigated the effects of available lightings on visual performance and atmosphere feeling. Lightings in the experiment included: LED, energy-saving lamp, tungsten, and a smart lighting product from Philips. 10 participants were asked to complete the experiment tasks and a questionnaire. The experimental tasks include: critical flickering frequency (CFF), calculation, proofreading, reading comprehension and a concentration test (d2 test). They were designed to test the visual performance of participants. The questionnaire was made up of categorical judgment of the atmosphere of lighting environment. It was designed to study the influences of lighting on people´s perception of atmosphere in the environment. The result revealed that Hue-energetic (6300K, 150cd/m²) made people performed best and that CCT and perception of brightness affected people´s feeling of activeness and comfort. Furthermore, it also confirmed that blue light could trigger energetic arousal.