From the moment you wake up to the moment your head hits the pillow, there’s one constant in your life—light. Whether it’s natural or artificial, in your home or your office, fluorescent or LED, light is always surrounding you.

For being so omnipresent in our lives, it’s remarkable how lighting isn’t always focused on what’s optimal for people. Surprisingly often, the various lights in our lives are too harsh, too dim, building-centric, or one-size-fits-all.

One company—PLANLED, based in Federal Way, Wash.—is betting that people fed up with inadequate illumination will embrace the new concept of human-centric lighting (HCL). PLANLED distributes, markets, and sells a variety of different HCL solutions for indoor, outdoor/sports, and industrial settings.

“We do have a commercial interest, of course, but our objective and our passion is how we can improve human lives,” said John Park, a business development manager at PLANLED. “Everyone works under electrical lighting, so improving that lighting affects everybody.”

Recently, Park worked with McKinstry Lighting Project Manager Ben Woodhouse to install four “tunable LED” fixtures in the Seattle office’s wellness center. The new fixtures are Samjin Beetles, PLANLED’s tunable white LED product. They are “tunable” because they can be instantly adjusted anywhere from a warm/yellowish-white color temperature of 2,700K (kelvin) to a cool/bluish-white color temperature of 6,500K.

According to Woodhouse, the fixtures’ adjustability can simulate the ebb and flow of daylight if pre-programmed, and they can also be set at whatever color temperature is most desirable for the occupant of that space or the activity performed in that space—thus making them HCL fixtures.

“It’s been great to showcase these fixtures, because it provides a visual demonstration of how color temperature plays a role in our perception of space and our mood, which is a difficult concept to explain with words alone,” Woodhouse said. “There’s a lot of debate over what color temperature is appropriate in various settings, and it’s helpful to get people’s thoughts when they can see the difference instantaneously.”

While the four fixtures in the wellness center provide a glimpse at the cutting edge of lighting, Woodhouse said the rest of McKinstry’s Seattle office is currently lit at a uniform, warm 3,500K by fluorescent fixtures—a typical American workplace set-up.

Park and PLANLED, however, are on a mission to evangelize the myriad benefits of tunable LED lighting and take HCL technology from the niche to the mainstream. According to Park, working and living under high-quality, flicker-less LED light with an adjustable color temperature can lead to higher productivity, better sleep, increased visual acuity and superior reading comprehension.

PLANLED has worked with Harvard neuroscientist Dr. Steven Lockley on research that aims to test and quantify the relationship between humans and light. One of the main research discoveries is that “warm” light at a low color temperature promotes the production of melatonin, a sleep hormone. In contrast, “cool” light at a higher color temperature suppresses melatonin production while encouraging the production of other hormones that promote alertness.

“Here in the U.S., the social norm of warm light is not always the appropriate color temperature,” Park added. “You’d ideally want cool light during the day and warm light at night, but in most settings you just get one or the other.”

A major group supporting HCL technology is the Human-Centric Lighting Society (HCLS). On its website, the HCLS makes the case that the proper use of “Kelvin changing or shifting” fixtures “can improve circadian rhythms, mood, visual acuity and performance in addition to substantial energy savings and sustainability.”

PLANLED has installed tunable LED fixtures in offices, warehouses, stadiums, and classrooms thus far. Park said it can be difficult to overcome the lighting status quo, but he and PLANLED are committed to promoting the benefits of tunable, human-centric LED lighting.

“The science is still progressing, but the concept has been well-received,” Woodhouse said. “LED lighting has given us the insight to question and test this correlation between light—both natural and artificial—and human health. I’m excited for the future of the lighting industry.”