The variety of light needed throughout the day is understated. The wellness criteria has a day-to-evening ratio of 25:1. Standard color tuning only provides a 2:1 ratio. To achieve true health and wellness benefits, different spectrum, wavelength, temperature, and direction of light at different times of day. This is why dynamic lighting is necessary in all buildings. Prioritizing this new metric, vertical m-EDI, in any space, whether it is commercial, residential, or multiuse has many benefits. Even in contemporary buildings with ample natural light sources (e.g. windows, patios, doors, etc.), using the right light is not just an investment in the physical space, but an investment for occupant wellbeing.
The sun-sky spectrum
As mentioned previously, one needs a minimum amount of vertical m-EDI throughout the day, which typically comes from natural sunlight. Luckily, for those who work and spend most of their time indoors, they are still able to get the appropriate amount of EDI from electric lighting. To implement electric lighting that supports wellness, there are a few ways to hunt down the right solution for a particular project. The key is to look for products designed to mimic the sun and the sky. It is more than just installing color-changing light bulbs, but rather about incorporating the blue reflection of the sky through different gradients of light temperatures.
One way to achieve this is using a dynamic electric light capable of transitioning throughout the day to offer stronger blue light and blue to white gradients during daytime and warmer amber to red gradients in the evening. For example, daylight on an overcast day is 6,500 K, while on a bright, sunny day, nothing is 6,500 K. Daylight is comprised of blue sky of 8,000 K and colder, where sunlight is 5,700 K and warmer.
When people are outdoors, the sun is never directly reaching them—it is always a mixture of the sun and sky that reflect in a specific manner. Throughout the day, the sky grows in the morning, gradually shifting to be brightest towards the peak of the day, and then slowly fades into a sunset. Sometimes there may be clouds, and other times it is bright blue skies. All these variations impact people, therefore, when weighing options, this is the top function to look for in products. Think of it as looking out of a window and seeing a mix of blue skies, clouds, light from different angles, compared to just turning on a light bulb or looking directly up at the sun.
Best practice for wellness-supporting lights
Contrary to popular belief, blue light is not always bad—the human body needs it in certain capacities. When deciding lighting options, the key is to look for technology that disperses blue light. Exposure to the full-spectrum light bodies need can feel uncomfortable to the eye; therefore, investing in lighting that prioritizes a mix of warm- and cool-toned light will help lessen overstimulation. Anything that emphasizes color dispersion is a great place to start.
It is also important to ensure the light fixtures are at an appropriate height. Research states blue light coming from the upper region of the gaze is biologically ideal, as the body is calibrated to the blue sky in nature. It is not always possible to install lighting on the vertical sightline plane, especially when working with high ceilings or nuanced building codes, but it is something to keep in mind and consider what can be done to make it easy on the eye.
Finally, keep an eye out for products that mimic the sun’s cycle to avoid circadian rhythm disruptions. Throughout the day, the sun naturally changes as it transitions through sunrise, daylight, sunset, nighttime, and design teams can find artificial lights that replicate that same gradual cycle. Even if one is working in a room with windows, it is still not enough exposure to signal these time-of-day transitions to the brain. There are many circadian lighting and wellness lighting options available—including desk lamps and individual light bulbs that transition.
Conclusion
For any working environment, it is important to supplement the right artificial light to ensure a healthy quality of life and occupant wellbeing.
The quality and type of light surrounding people in their home, workplace, stores, gym, etc., directly correlates to their quality of life. By rethinking indoor lighting to focus on health in addition to function, specifiers can support the health of building inhabitants for years to come. CS
Notes
1 Read the research on the importance of lighting, https://doi.org/10.1016/j.cub.2016.04.011.
2 See the 2022 wellness lighting recommendations at https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3001571.
3 Learn more about light and health, www.ncbi.nlm.nih.gov/pmc/articles/PMC8707256.
4 Review this link for more information on how to quantify m-EDI https://cie.co.at/publications/cie-system-metrology-optical-radiation-iprgc-influenced-responses-light-0.
Author
Robert Soler is the cofounder of SkyView, a leader in human wellness lighting technologies. Prior to his work at SkyView, his most prominent work was at Kennedy Space Center, where he was the subject matter expert for NASA‘s circadian lighting system to synchronize astronauts to a 24-hour cycle onboard the International Space Station. He received a fellowship from the National Science Foundation (NSF) and currently serves on the light advisory committee for the International WELL Building Standard.
