Healthcare facilities have more options and strategies than ever before to adopt circadian lighting.

circadian lighting whit home

circadian lighting whit home

A bedroom at the Whit Home project in Lake Nona, Fla, utilizes Healthe Lighting SunTrac Dual Channel A19, as well as the company’s Good Day&Night Downlights.

Night and day can sometimes become confused in the healthcare setting. Patients may be awakened, not when they should, but when it’s necessary or convenient to provide care. Healthcare workers—particularly those who work at night—may be working in too low or too intense lighting conditions that affect their alertness and productivity.

There are significant benefits for healthcare enterprises if they provide circadian lighting conditions. For example, researchers have found bright morning illumination in hospital rooms to be linked to shorter inpatient stays.1

Appropriately timed lighting also benefits employees. A Harvard study found that nurses exposed to the highest levels of outdoor light at night had an estimated 14% increased risk of breast cancer, as compared with women in the lowest levels of nighttime exposure. The link was stronger among nurses who worked night shifts.2

With the increasing understanding of circadian rhythms, and, most importantly, how light of different wavelengths can align or disrupt our natural sleep cycles, healthcare organizations now have the means to adjust their lighting schemes to better promote patient recovery and employee productivity.

It’s About the Melatonin

Fundamentally, the goal of circadian lighting is not necessarily about illumination, but about how it is promoting entrainment, according to Mariana Figueiro, PhD, director of the Lighting Research Center (LRC) and professor of architecture at Rensselaer Polytechnic Institute.

With a circadian approach to lighting, which would shift from visibility to entrainment, patients would get better sleep, which Figueiro says would have “cascading benefits.”

While there’s still more large-scale research that needs to be done, she notes that there have been strong benefits from circadian lighting schemes in nursing homes, including improved sleep and less depression and agitation.

Exposure to certain wavelengths of light suppresses melatonin production. When melatonin is suppressed prior to or during natural sleep times, this disrupts the internal clock, potentially causing sleep and related health problems.

“Recurrent or persistent mismatch between the internal clock and the environment can give rise to sleep disturbance, sleepiness and fatigue, cognitive impairment, and worse quality of life,” says Teofilo Lee-Chiong Jr., MD, professor of medicine at the University of Colorado Denver School of Medicine and chief medical liaison at Philips Respironics. “Circadian lighting has been shown to decrease delirium among hospital patients and improve work performance and decrease tiredness and sleepiness during shift work among nurses.”

Relighting the Healthcare Environment

Sleep Center Virginia Hospital

The Sleep Center at the Mayo Clinic – Virginia Hospital Center uses Healthe Lighting’s Good Day&Night Downlights and GoodNight lamps.

Some healthcare facilities have already begun redesigning their lighting schemes to encourage entrainment—or at least minimize circadian disruption—for patients and night employees.

“Recognizing the importance of properly-timed bright light therapy on sleep quality and daytime alertness, healthcare facilities have begun to redesign workplace lighting to improve both patient outcomes and the performance of the hospital teams,” says Lee-Chiong. “Increased natural lighting through windows and augmented artificial light systems can increase light intensity during the waking hours. Window shades and door-side curtains limit light exposure in the patient room during sleep periods. At the same time, bright ambient light is provided in work areas to help mitigate some of the unwanted consequences of altered sleep-wake patterns related to shift work among the hospital staff.”

That being said, at least at this time, there is a tradeoff that healthcare facilities need to make for their employees, according to Khim Lee, CEO of Healthe Healthcare, a provider of circadian lighting systems for health facilities.

“There is a balance between productivity and safety,” he says. “At the end of the day the last thing we want to do is disrupt employees’ circadian rhythms. With the use of circadian day light there is a necessary tradeoff for the work they must do.”

He notes that there have been studies that indicate that nurse medication errors are more likely during darker months than in months when there is more daylight.3

Lee-Chiong adds that lighting for employee areas should be used to keep circadian rhythms in balance. “Published studies have used various light intensities from 2,350 to 12,000 lux in work areas, and different lighting schedules, including four 20-minute periods during night duty, half of a 12-hour night shift, six hours of intermittent light exposure, and 20 minutes during break from work,” he says. “Future research is needed to identify the proper timing, intensity, and duration of circadian lighting in work areas.”

Adding circadian lighting to a healthcare facility ranges from relatively simple to complex—which can impact the costs. For example, Healthe’s solution is quick—and by design, according to David Rubin, Healthe’s vertical expert, since healthcare facilities can’t afford to have a treatment area down for a long period of time.

Healthe has recently completed an installation at the sleep center at Virginia Hospital Center in Arlington. A lighting challenge for sleep centers, Rubin notes, is that clinicians are trying to recreate the lighting environment of the patient’s home in an attempt to identify if lighting is one of the patient’s issues.

Lee-Chiong notes that often sleep patients are given lightboxes as part of their treatment to see if circadian lighting would be beneficial.

Interestingly, staff at sleep facilities could probably benefit more than patients from improved lighting schemes.

“Lighting is important for sleep staff, since they shouldn’t be falling asleep on their nighttime shifts,” Rubin says. “Labs can be in strip malls, so the clinician doesn’t own the location and is stuck with the light that was already there.”


There is evidence that the Philips Wake-up Light improves mood and makes users feel more energized in the morning.

Lee-Chiong notes that if a sleep lab needs a more extensive lighting update, it can be rather involved. “Costs related to upgrading the circadian lighting of sleep laboratories include the prices of the light fixtures, electrical wiring, wall outlets, curtains, shades, paneling, and light diffusers,” he says. “Ideally, light intensities should be adjustable, and many systems offer full automation.”

Blue or Red?

While there are a number of theories surrounding the way light needs to be used, particularly for night employees, and there may currently be tradeoffs, as Healthe’s Lee outlined, Figueiro’s latest research may make the need to have any tradeoff unnecessary.

She and her team are currently working on a National Institute for Occupational Safety and Health-funded study to determine the efficacy of using a red-frequency light in work settings. “We’ve had very positive results,” she says of her initial findings. “Red light promotes alertness but doesn’t suppress melatonin.”

If these initial findings are confirmed, it could have significant benefits for night shift workers, improving sleep and mood and combating serious diseases—including diabetes and obesity.

New data will continue to emerge about the best way to promote entrainment in health settings, but one thing is already settled—it benefits patients and employees.

Top photo: The Sleep Center at the Virginia Hospital Center uses Healthe Lighting’s Good Day&Night Downlights and GoodNight lamps.

While doing research on circadian lighting, L.A.-based freelancer C.A. Wolski was gratified to learn that — by happy accident — he works by the right amount and type of light on a daily basis.


1. Choi JH, Beltran LO, Kim HS. Impacts of indoor daylight environments on patient average length of stay (ALOS) in a healthcare facility. Building and Environment. April 2012;50:65-75.
2. James P, Bertrand KA, Hart JE, et al. Outdoor light at night and breast cancer incidence in the Nurses’ Health Study II. Environ Health Perspect. 2017 Aug 17;125(8):087010.
3. Roseman C, Booker JM. Workload and environmental factors in hospital medication errors. Nurs Res. 1995 Jul-Aug;44(4):226-30.