Numerous studies have identified the need for better lighting conditions in senior care facilities. Residents often have too little exposure to natural light during the day and are subjected to leaks from artificial lighting during the night. This can lead to a range of health problems, from erratic sleep patterns to impaired cognition to listlessness and depression.

Recent developments in LED technology may provide a solution by creating interior lighting conditions that change throughout the day and night, mimicking the natural light cycle to which the body is attuned.

Results of studies on sleep quality and lighting examined as part of a comprehensive literature review of research on older adults’ visual and nonvisual performance conducted by a team from the University of Florida, Gainesville (including Nam-Kyu Park with the Department of Interior Design) indicate that “daylight exposure benefits older adults’ sleep quality, and nighttime/evening lighting exposure has a negative impact on older adults’ sleep quality.”

Other studies have shown that lighting levels affect the production of melatonin that helps to regulate the body’s circadian rhythms, which, in turn, affect sleep patterns. As we age, changes occur which alter normal circadian rhythms, as can conditions such as Alzheimer’s, making this a critical issue in senior care.

The authors of a paper advocating for human-centric lighting design, recently published in the journal Lighting Research and Technology, point out that while lighting for visibility, visual comfort and visual amenity is important, equally important is recognizing how light and lighting influence non-visual responses in humans. “Circadian, neuroendocrine and neurobehavioural responses are important for human health and should be considered on-par with visual responses,” they state. “This awareness leads toward lighting design solutions with increased contrast between day and night.”

Previous attempts to simulate the quality and level of natural light in senior care have produced mixed results because the technology was not adequate or relied on manual controls. The introduction of LED technology has changed that. In 2013, faculty members from the College of Engineering at Drexel University presented a paper in which they announced that they were developing an “energy-conserving diurnal daylight-matching LED luminaire to improve health outcomes for the elderly at St. Francis Country House near Philadelphia, Pennsylvania.”

In 2016, the U.S. Department of Energy published a report of a project it funded under its GATEWAY program, Tuning the Light in Senior Care, which summarizes the results of a trial installation of light-emitting diode (LED) lighting systems in several spaces within the ACC Care Center in Sacramento, California. The study used solid-state LED technology to “tune” the lighting to different levels at different times of the day in order to mimic natural light cycles.

In some areas, the lighting was controlled manually by the staff. The corridor lighting was programmed to change automatically but could be overridden with a manual control. Among the health benefits observed by the staff that may have been attributable to the change in lighting were a 41% reduction in yelling, agitation and crying for three residents, improved sleep without interruption, and reduction in the use of sleep and psychotropic medications.

More recently, a team led by researchers from the Brown University School of Public Health’s Center for Long-Term Care Quality & Innovation (and including Eunice Noelle-Wagner, president, Center of Design for an Aging Society) conducted an additional research study at the ACC Care Center that expanded the scope and employed the use of automated tuned lighting to change color and intensity settings automatically during the course of the day and night.

At the end of the two-month intervention, they found that the residents in those areas with autotuned lighting experienced half as many nighttime sleep disturbances as did the control group that were exposed to static lighting conditions. Unlike the previous study, they did not observe significant differences in agitate behaviors.

While more research is needed, the results of these studies is promising. The authors of the literature review cited above caution that some studies to date point to “other related physical environment factors, such as noise, that may interact or coincide with lighting and affect sleep quality.” Even so, advances in lighting technology appear to open new avenues for addressing a major issue in the design of interior environments in senior care facilities.

As the authors of the paper on human-centric lighting design state in their conclusion, “The parties responsible for addressing non-visual responses to light and lighting are evolving. Architects, lighting professionals, lighting equipment manufacturers, medical professionals, building owners and individuals all have a stake.” That includes interior designers as well.