You may have heard of Seasonal Affective Disorder (SAD), which can affect people who live in winter climates with limited natural sunlight. But researchers are now learning how light affects our non-visual responses.
Non-visual responses include those that affect our biological systems. These are not task-oriented needs, such as reading, spending time on screens, and doing fine needlework. Non-visual responses have to do with our circadian rhythms, pupil dilation, alertness, and melatonin suppression.
One thing the research tells us is that LEDs offer a distinct advantage over traditional, older technologies. Specifically, their color and intensity can be customized to support both task- and non-task situations. However, because this is relatively new research, it’s important to note that poorly-engineered LED solutions may cause harm.
Much has been written about the negative effects of blue-spectrum light – the higher end of the Kelvin scale - on our health. While it is true that blue light can disrupt our sleep and make us more alert, that’s not always a bad thing. When selecting what works in your environment, be sure to ask:
- Do you want to minimize the non-visual response to light? This could be the goal when you want to get a good night’s sleep. If this is your goal, choose an LED light at the lower, warmer end of the spectrum.
- Do you want to activate the non-visual response? This may be desirable to help keep workers awake and alert on overnight shifts. In such situations, you could benefit from LEDs at the higher (blue) end of the spectrum.
Research has also shown that the blue spectrum of LED lights is no more inherently harmful than the blue spectrum of other types of lighting. LED lights may look brighter than other types of lighting, but they do not emit more blue energy as other lights when evaluated at the same color temperature.
The challenge remains in determining how you will be using various forms of light. In shared workplaces and buildings open 24/7, such as hospitals, it is vital to think about the kinds of activity that should be supported – and at what times of day and night. When coming up with a sound LED solution, be sure to consider comfort, aesthetics, and energy consumption as well.
To learn more about what new research is telling us, click here to open a publication by the U.S. Department of Energy.