Below is an application story I contributed to the November issue of tED Magazine, the official publication of the NAED. Reprinted with permission.
Nearly 50 million people aged 65 and over live in the United States, with about 1 million living in more than 30,000 assisted-living communities, according to the National Center for Assisted Living.
Moving forward, according to the Population Reference Bureau, the 65+ segment of the population is expected to double to nearly 100 million by 2060, increasing its total population share to 24 percent. This will very likely result in increased demand for senior facilities in the future.
These facilities range from retirement housing to assisted-living facilities to nursing homes and hospice, with the average age being 83 to 86. They can be challenging for lighting design, as the visual system undergoes physiological changes with age that can reduce visual acuity and color discrimination while heightening sensitivity to glare.
As a result, a higher percentage of elderly people have vision impairment compared to the rest of the population. Vision in dim lighting, reading small print, distinguishing colors, and transitioning between bright and dim spaces can all be problematic. Eye diseases such as glaucoma and cataracts become more common. Disruption of circadian rhythms may occur, either due to degradation of sight or possibly Alzheimer’s disease or dementia.
Lighting design for these facilities typically emphasizes daylight and higher electric light levels, minimizing glare through indirect light distribution and other means, good uniformity of light distribution, and accent lighting for safety. Transition spaces receive high illumination for visual adaptation. Flicker should be avoided. As people live in these facilities, the lighting should promote circadian entrainment, and the lighting equipment should be pleasant and promote a sense of home.
This article introduces basic lighting design principles for senior facilities, based on two documents. The first is the Facility Guidelines Institute’s 2018 FGI Guidelines for Design and Construction of Residential Health, Care, and Support Facilities. The second is the Illuminating Engineering Society’s (IES) ANSI/IES RP-28-16, Lighting and the Visual Environment for Seniors and the Low Vision Population.
Lighting for Living
Designers should plan the lighting based on the site conditions, building orientation (for daylight), and the needs of the care population. The greater the need for care, the more impact the physical environment can have on quality of life and overall safety. Therefore, the lighting should be verified to be responsive to residents’ daylighting and electric lighting needs.
The design of senior care facilities is not regulated at the national level, with states making the rules. A majority of states have regulations based on the FGI guidelines. For lighting, these guidelines cover various design aspects, while referencing IES RP-28 for minimum recommended light levels, which are typically higher than for other types of applications. Otherwise, the Americans with Disabilities Act (ADA) prohibits wall objects such as sconces projecting more than 4 inches into circulation zones when mounted 27 to 80 inches above the finished floor.
The FGI guidelines require daylighting in common areas such as dining and activity rooms, while recommending it wherever else possible based on its value for light levels, color quality, and circadian entrainment. The guidelines add that if daylight is not available, the electric lighting should promote circadian response, which may be accomplished with intensity and color control in LED luminaires.
Daylight can be balanced with light shelves, skylights, and other methods. To control brightness and minimize glare, daylight apertures should be properly shaded. Similarly, lamps and luminaires should be properly shielded or concealed to minimize glare, while producing lighting patterns free of glare, shadows, and scalloping. This may involve shielded direct lighting or indirect lighting. Daylight, general and task electric lighting, and surface reflectances should combine to produce the desired maintained light levels based on IES recommendations.
A key consideration for senior living is visual adaptation. This is the ability of the eye to adapt from one light level to another so as to maintain the same level of visual acuity. For many elderly people, adaptation between extreme contrasts—such as leaving bright sunshine to enter a dim building—can reduce visual acuity and may even be disorienting. As a result, transition/entry spaces such as lobbies and vestibules require higher light levels to assist with adaptation. If residents will enter a space with a very low light level, seating may be provided to give them time to adjust. Similarly, windows at the end of corridors should be properly shaded.
In living spaces, residents should be given easily accessible task lighting. Low-level night lighting should be provided that is mounted no higher than 2 feet above the finished floor. In case the night lighting may be disturbing, it may be portable or able to be switched. Additionally, corridor general lighting should reduce at night using controls.
Regarding color, the IES recommends a minimum light source color rendering index (CRI) rating of 80 for interior spaces at senior facilities—preferably higher in specific spaces such as hobby areas, dining rooms, and elsewhere color accuracy, discrimination, and appearance are important. The IES also recommends a slightly higher correlated color temperature (CCT). A high CRI and slightly higher CCT (e.g., 3000K instead of 2700K), which can help mitigate loss of color discrimination that can occur with age.
Alzheimer’s and dementia
Alzheimer’s disease is a type of dementia, the incidence of which increases with age. The Alzheimer’s Association estimates that 5.7 million Americans aged 65+ have Alzheimer’s disease—about 10 percent of that age group, and about one-third of people age 85 and over. Because there is no cure, the best outcome is to minimize symptoms. Design can play a role.
Alzheimer’s can affect vision, including negative effects on depth perception, loss of peripheral vision, inability to discern brightness contrast, reduction in visual acuity, and heightened sensitivity to glare and shadows. These problems can contribute to falls and reduced postural stability.
According to the IES, some caregivers have suggested a higher light level than the organization’s recommended minimum. Besides ensuring sufficient illumination, additional steps such as ensuring strong color contrast can improve quality of life.
Providing circadian-friendly lighting may also be beneficial. This may include adjusting light levels and spectral output based on time of day. It may also include incorporating lighting that delivers sufficient light to the eye’s photoreceptors during the day.
In one study published in 2016, the Lighting Research Center (LRC) developed a self-luminous light table to complement customized general lighting. The table delivers a circadian stimulus (CS) of 0.4, above the threshold for circadian stimulus. According to the LRC, the results included significantly improved sleep, reduced depression, and reduced agitation in Alzheimer’s patients. Even after the light intervention was removed, both depression and agitation scores remained lower.
Lighting for seniors
Seniors deserve the best quality of life that good design has to offer, ensuring a physical environment that supports their needs. This includes lighting designed to recommended practice. Good lighting for senior facilities mitigates vision issues that can occur with aging, supporting visual acuity as well as their ability to discern brightness and color contrast.
SIDEBAR: Tunable-White Lighting at ACC Care
In 2015, the Sacramento Municipal Utility District (SMUD) evaluated a trial installation of tunable-white LED lighting at the ACC Care Center, a senior living facility. SMUD and ACC collaborated to learn more about how tunable-white lighting impacts sleep, nighttime safety, and behavior, following guidelines published by the LRC.
At specification time, few tunable-white luminaires were suited to replace the existing fluorescent system. Several luminaires were installed in a corridor, two resident rooms, a nurse’s station, a family common area, and an administrator’s office. Light levels improved in the resident rooms due to the LED lighting, while the spectral output of the lighting in these rooms plus the adjacent corridor and nurse’s station changed throughout the day to support circadian entrainment.
According to the U.S. Department of Energy (DoE), which published the project as a GATEWAY study, the ACC staff captured health-related benefits that may be attributable to the new lighting. These included less agitated behaviors in three studied patients, with a marked reduction in use of psychotropic and sleep medications for one of them. Further, the number of patient falls in the corridor was reduced.