Toward a Connected System—Understanding the Contribution of Light from Different Sources on Occupants’ Circadian Rhythms
Source abstract
Abstract
Light that enters humans’ eyes and impacts circadian rhythms may come from various sources, including the sun, electric lighting systems, and self-luminous displays. Occupants’ activities strongly impact the light entering their eyes, which is difficult to predict and not yet well understood. This study investigated the circadian contributions of light from different sources in real building environments to better understand the variables that influence the circadian health of occupants. Spectral irradiance distributions at a position equivalent to the front of an eye of a seated occupant in various interior office spaces were collected. Daylight and electric light were measured separately, and light emitted from displays was measured when a variety of different computer tasks was performed. Circadian stimulus (CS) and α-opic irradiance, defined by CIE DIS026/E:2018, were further calculated, and the circadian effects of light from different sources were compared. The results show that daylight has the greatest circadian effect, while electric light in spaces that were predominantly designed with conventional downward lighting has a very limited impact. The circadian effect of light from screens was considerably high. The outcomes suggest that, to optimise the circadian effects of light, connected lighting systems are needed to control light from different sources.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Impact of Light on Environment and Health · Circadian rhythm and melatonin · Building Energy and Comfort Optimization
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
School of Architecture, Design and Planning, The University of Sydney, Sydney, NSW 2006, Australia
References (40)
Show source-provided references
1. Circadian photobiology: An emerging framework for lighting practice and research10.1191/1365782802lt057oa ↗
2. Light as a circadian stimulus for architectural lighting10.1177/1477153516682368 ↗
3. Lighting for work: A review of visual and biological effects10.1191/1365782804li122oa ↗
4. Measuring and using light in the melanopsin age10.1016/j.tins.2013.10.004 ↗
5. Chellappa, S.L., Steiner, R., Blattner, P., Oelhafen, P., Götz, T., and Cajochen, C. (2011). Non-Visual Effects of Light on Melatonin, Alertness and Cognitive Performance: Can Blue-Enriched Light Keep Us Alert?. PLoS ONE, 6.10.1371/journal.pone.0016429 ↗
6. Healthy, natural, efficient and tunable lighting: Four-package white LEDs for optimizing the circadian effect, color quality and vision performance10.1038/lsa.2014.22 ↗
7. Daylight and health: A review of the evidence and consequences for the built environment10.1177/1477153513509258 ↗
8. Indoor exposure to natural bright light prevents afternoon sleepiness10.1093/sleep/29.04.462 ↗
9. Window blind occlusion: A pilot study10.1016/0360-1323(84)90038-6 ↗
10. Rubin, A.I., Collins, B.L., and Tibbott, R.L. (1978). Window Blinds as a Potential Energy Saver: A Case Study, U.S. Department of Commerce, National Bureau of Standards.10.6028/NBS.BSS.112 ↗
11. Manual control of window blinds and electric lighting: Implications for comfort and energy consumption10.1177/1420326X9400300307 ↗
12. Lightswitch-2002: A model for manual and automated control of electric lighting and blinds10.1016/j.solener.2004.04.003 ↗
13. Circadian-effective light and its impact on alertness in office workers10.1177/1477153517750006 ↗
14. Study on the effect of awakening daylight in dormitories on morning alertness, mood, fatigue and sleep quality of college students10.1016/j.buildenv.2021.108060 ↗
15. Effects of realistic office daylighting and electric lighting conditions on visual comfort, alertness and mood10.1177/1477153514531518 ↗
16. Lighting in educational environments: An example of a complete analysis of the effects of daylight and electric light on occupants10.1016/j.buildenv.2013.04.005 ↗
17. Impact of windows and daylight exposure on overall health and sleep quality of office workers: A case-control pilot study10.5664/jcsm.3780 ↗
18. Henry, J. (2010). Generation m2: Media in the Lives of 8- to 18-Year-Olds, Kaiser Family Foundation.
19. Nilsson, M. (2015). Ultra high definition video formats and standardisation. BT Media and Broadcast Research Paper, 1Library.
20. Lighting does matter: Preliminary assessment on office workers10.1016/j.sbspro.2013.10.283 ↗
21. Reading from an iPad or from a book in bed: The impact on human sleeA randomized controlled crossover trial10.1016/j.sleep.2016.02.006 ↗
22. Light level and duration of exposure determine the impact of self-luminous tablets on melatonin suppression10.1016/j.apergo.2012.07.008 ↗
23. Evening exposure to a light-emitting diodes (LED)-backlit computer screen affects circadian physiology and cognitive performance10.1152/japplphysiol.00165.2011 ↗
24. Two hours of evening reading on a self-luminous tablet vs. reading a physical book does not alter sleep after daytime bright light exposure10.1016/j.sleep.2016.06.016 ↗
25. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness10.1073/pnas.1418490112 ↗
26. Real life trumps laboratory in matters of public health10.1073/pnas.1500717112 ↗
27. Phototransduction by retinal ganglion cells that set the circadian clock10.1126/science.1067262 ↗
28. CIE (2018). CIE S 026/E:2018: System for Metrology of Optical Radiation for Iprgc-Influenced Responses to Light, CIE (Commission Internationale de L’Eclairage).
29. Price, L. (2015). CIE TN003:2015, Report on the First International Workshop on Circadian and Neurophysiological Photometry, CIE (Commission Internationale de L’Eclairage).
30. The impact of daytime light exposures on sleep and mood in office workers10.1016/j.sleh.2017.03.005 ↗
31. Modelling the spectral sensitivity of the human circadian system10.1177/1477153511430474 ↗
32. Action spectrum for melatonin regulation in humans: Evidence for a novel circadian photoreceptor10.1523/JNEUROSCI.21-16-06405.2001 ↗
33. An action spectrum for melatonin suppression: Evidence for a novel non-rod, non-cone photoreceptor system in humans10.1111/j.1469-7793.2001.t01-1-00261.x ↗
34. Howell, D.C. (2012). Statistical Methods for Psychology, Cengage Learning.
35. Self-luminous devices and melatonin suppression in adolescents10.1177/1477153515584979 ↗
36. Spectral optimisation and a novel lighting-design space based on circadian stimulus10.1177/1477153517733504 ↗
37. IWBI (2019). The WELL Building Standard™, The International WELL Building Institute.
38. Standards Australia (2008). Interior and Workplace Lighting-Specific Applications-Office and Screen-Based Tasks, Standards Australia. AS/NZS 1680,2.2:2008.
39. Standards Australia (2008). Interior and Workplace Lighting-Specific Applications-Educational and Training Facilities, Standards Australia. AS/NZS 1680,2.3:2008.
40. National Standards Authority of Ireland (2011). Light and Lighting-Lighting of Workplaces-Part 1: Indoor Workplaces, National Standards Authority of Ireland. I.S. EN 12464-1:2011.