Effects of dynamic lighting on the visual performance of older adults L Izso ´ DSc a , L Laufer MA a and S Suplicz MS b a Department of Ergonomics and Psychology, Budapest University of Technology and Economics, H-1111 Budapest, Muegyetem Rakpart 3-9, Hungary b Budapest Tech Polytechnical Institution, H-1034 Budapest, Becsi Street 96b, Hungary Received 21 September 2008; Revised 3 April 2009; Accepted 9 April 2009 This is the second of the three papers providing fundamental information for the development of an adaptive lighting system for older adults. This paper examines the effects of two different forms of dynamic lighting – having the same average illuminance over time – on the performance of the numerical verification task (NVT) by older adults. As a group, the older adults showed no difference between the two forms of dynamic lighting. However, by involving the individual’s sensation seeking needs it was shown that the kind of dynamism (quickly increasing or quickly decreasing) influences both the subjective preferences and the objective visual performance. As individuals, all of the participants’ performances were determined mainly by the time, and illuminance variables proving the effect of dynamic lighting. 1. Introduction This paper is the second of three papers providing fundamental information for the development of an adaptive lighting sys- tem for older adults within the framework of the ALADIN (Ambient Lighting Assistance for an Ageing Population) proj- ect. 1 The first paper, entitled ‘Psychophysio- logical, performance and subjective correlates of different lighting conditions’, dealt with general psychophysiological, performance and subjective effects of different fixed light- ing conditions. The goal of the present paper is to study the effects of dynamic lighting. Dynamic lighting is, by our definition, light- ing providing light output parameters varying over time so that this variation can be perceived by people. The varying lighting parameters can be illuminance or spectral characteristics or both. As natural lighting is almost always dynamic, there are probably biological mechanisms in humans that make them prefer varying lighting rather than fixed lighting. The basic idea behind the desire to use dynamic lighting is that dynamic lighting with carefully chosen characteristics could induce better performance and lower work- load, and as a consequence also lower mental strain at the same time. A correctly timed change in illuminance or color temperature will periodically stimulate the arousal that otherwise would have decreased under fixed lighting due to processes such as habituation, fatigue, monotony or saturation. Some light- ing system manufacturers already provide dynamic lighting systems. 2 In previous work, we conducted laboratory experiments studying the effect of dynamic lighting on the visual performance and the related feelings of young people. 3–5 Address for correspondence: Laszlo Laufer, Department of Ergonomics and Psychology, Budapest University of Technology and Economics, H-1111 Budapest, Muegyetem Rakpart 3-9, Hungary. E-mail: laszlo.laufer@gmail.com Lighting Res. Technol. 2009; 41: 361–370 ß The Chartered Institution of Building Services Engineers 2009 10.1177/1477153509336802