In this article, we will define what light is in relation to our mind and body, the five senses and beyond, to better understand its impact and effect on our work environment.

(Yoko’s snapshot) Early Spring.  Outside my window, the sunlight is bright enough to not need the ceiling lights on.  It feels warm near the window. A small desk lamp is all I need to read by. The surface of my keyboard is bathed in the glow from my monitor. The sun creates shadows of the trees across my desk.

What is Light and How Do We Perceive It

In the snapshot, I am experiencing three (3) different types of light:  sunlight (natural light), electric light, and secondary light from a monitor. But what exactly is light for us? It is not easily defined in everyday terms. We’ve organized the meaning of light into three categories/senses to better illustrate what it is and what it does in our work environments. 

  1. Light as objective matter that we see (visible light) and it shines on something to help us see it.  Although it is objective in the sense that it can be measured, light in this sense initiates different levels of sensory response in people. i.e. Light may be too bright for someone but not for others.  
  2. Light as matter that influences our entire body, not just our vision.  Light warms our bodies and surroundings. Light sends cues to our body’s circadian rhythms (physical, mental, and behavioral changes that follow a 24-hour cycle1National Institute of General Medical Sciences. https://www.nigms.nih.gov/education/fact-sheets/Pages/circadian-rhythms.aspx accessed on 08/20/21) that are essential to keep us balanced.
  3. Light as agency that caters certain moods, meanings, or morals to our experience of space.2Bille, Mikkel, and Tim Flohr Sørensen. “An Anthropology of Luminosity: The Agency of Light.” Journal of Material Culture 12, no. 3 (November 2007): 263–84. https://doi.org/10.1177/1359183507081894. Certain light conditions can make us feel sad, sacred, or welcomed. In a church, the lighting is soothing and gives us a sense of peace. Reception area lighting promotes a feeling of welcome. Although there are cultural and personal differences, we can use the power of light as an agent to create better work environments which is almost always overlooked.

We do not consciously think of it, but we cannot separate light and our perception of it. We need to think of them both in order to assess and respond to light from a human-centric view in the work environment.

We cannot separate light and our perception of it.

Issues and Effects of Light in the Workplace

The three categories of light work individually or together to influence our body, mind, and productivity in the workplace. It is important to point out that its influence in the workplace can also be negative as well as positive.

When light in the first sense is not right for our eyes, (too dim, too bright, or with glares), it can cause eye strain, headaches, or even injury.3Mainster MA, Turner PL. Glare’s causes, consequences, and clinical challenges after a century of ophthalmic study. American journal of ophthalmology. 2012;153(4):587-593. When light in the second sense is too different from the natural day-night cycle, it disrupts our circadian rhythm which causes sleep disorders and can increase the risk of heart disease4Cappuccio FP, Miller MA. The epidemiology of sleep and cardiovascular risk and disease. Oxford University Press; 2010., diabetes and some cancers5Sack R, Auckley D, Auger R, et al. Circadian rhythm sleep disorders: Part II, advanced sleep phase disorder, delayed sleep phase disorder, free-running disorder, and irregular sleep-wake rhythm. Sleep. 2007;30(11):1484-1501. .

Bad lighting can also contribute to depression at work. Darkness, which is usually understood as the lack of light, is associated with depression or lower psychological mood in many studies. Objective and subjective darkness6Rikard Küller , Seifeddin Ballal , Thorbjörn Laike , Byron Mikellides & Graciela Tonello (2006) The impact of light and colour on psychological mood: a cross-cultural study of indoor work environments, Ergonomics, 49:14, 1496-1507, lack of exposure to daylight, and the negative connotation darkness brings to our minds7Johanesson, Gunner Thor, and Lund, Katrin Anna. “Aurora Borealis: Choreographies of darkness and light.” Annals of Tourism Research 63 (2017) 183–190. are all factors related to the three categories of light, and when combined can be instrumental in causing depression.

It is interesting, and we’d like to emphasize from the business point of view, that when measures are taken to alleviate these light-related issues, they also enhance the quality or quantity of our work.  For example, meeting lighting standards (in the first sense) improves visual comfort and productivity.8Castillo-Martinez A, Medina-Merodio J-A, Gutierrez-Martinez J-M, Aguado-Delgado J, de-Pablos-Heredero C, Otón S. Evaluation and Improvement of Lighting Efficiency in Working Spaces. Sustainability. 2018;10(4):1110. This is especially true for work that relies on good visual acuity, as many computer-based jobs do.9Parsons KC. Environmental ergonomics: a review of principles, methods and models. Appl Ergon. 2000;31(6):581-594. Exposure to high-intensity or short-wavelength light, such as day-light, improves people’s alertness10Lockley SW, Evans EE, Scheer FAJL, Brainard GC, Czeisler CA, Aeschbach D. Short-wavelength sensitivity for the direct effects of light on alertness, vigilance, and the waking electroencephalogram in humans. Sleep. 2006;29(2):161-168. and mood11Schwartz RS, Olds J. The psychiatry of light. Harv Rev Psychiatry. 2015;23(3):188-194..

We cannot separate light and our perception of it.

Y. Kawai & Y. Burton

Light and how we perceive it affects us in many unseen ways.  Good lighting positively contributes to our vision, mood, and productivity as stated in the three categories in this article.  Issues stemming from bad lighting should be corrected to maintain standards of well-being and work quality.

In our next article, we continue our discussion of Light with a focus on maximizing the benefits of good lighting and alleviating the negative effects of bad lighting.  

(Written by Yoko Kawai and Yvonne Burton)