Designing Nightlights to Facilitate Evening Activities among Older Adults: Illuminance and Hue Preferences

Studies have associated nighttime falls among older adults with their susceptibility to high light intensity and sensitivity to specific color tones of light. Based on that, this research aims to analyze the design of light to support the functioning of older adults during night hours. Older adults were recruited to explore older adults’ preferences in nightlight illuminance level and color ($n=10, 84.5 \pm 3.5$ years old. males). Their subjective measures (i.e., preference rankings) and objective measures (i.e., walking performance) were measured in different light conditions. The results indicated that older adults leaned towards dim lighting over bright lighting and favored cool colors over warm color’s for their homes. Notably, when we assessed the objective measure of the walking performance of older adults, we observed a minor deviation from their subjective preferences in illuminance levels. This suggests a balanced approach, considering both subjective preferences and objective measures, is advisable for practical applications in lighting design for older adults.

I. Introduction

Older adults remain a population common with vision difficulties, especially during night hours. The prevalence rate of vision difficulties among older adults is estimated at 3 for every 60 individuals [1]. With vision difficulties, older adults were reported to endure a higher cognitive load, or even, cognitive difficulties during the nighttime. Such cognitive difficulties are reported to expose the older population to falling accidents during nighttime, therefore, undermining their quality of life [2]. It has been reported that falls remain a health risk for this age group. Older adults, for instance, may experience cases of bone fracture, brain damage, and other complications that render them incapable of performing normal life duties [2]. Several studies associate falls among the population at night hours as caused by their vulnerability to high light intensity as well as their sensitivity to certain color tones of light. Petersen et al. (2018), for instance, suggest that the type of lighting that people of old age are exposed to influences their active levels of working at night hours. The researchers pinpoint that more than 50% of this population associate their cases of falls with high light intensity [3]. Dargent-Molina and colleagues evidence that the exposure of older adults to cases of insufficient lighting environment would increase the chances of them experiencing falls [4]. Such non-consented lighting areas would increase cases of the old population’s misperception of objects. This population can also misjudge object distances and are more vulnerable to getting stripped by the same objects. Darker tones of color, for instance, do not reflect light easily causing vision difficulties and falls among older adults. Brighter colors including red, yellow, and orange are, however, easy to see and remain crucial to eradicating cases of falling among older people [5]. Both the color and illumination levels, therefore, influence the normal functioning of people of old age during night hours. The concern to improve the well-being of older adults is, therefore, dependent on them accessing safe light for their proper visioning. It is, therefore, necessary for the current research to investigate and recommend appropriate interventions to implement appropriate levels of lighting and colors to support their normal functioning during night hours.