Exposure to appropriate levels of bright light directly affects human circadian rhythms. The circadian rhythm plays a key role in overall human well-being. Previous research suggests that elderly patients within residential care homes are often exposed to low levels of light, which can result in circadian misalignment and irregularities in sleep/wake cycles. Low lighting levels also have been attributed to deterioration in cognitive ability and human visual systems. Within the visible light spectrum, blue light is known to have the greatest influence on human circadian rhythms.
To investigate personal blue light exposure, illuminance levels, and health variables in residential care homes across two seasons to gauge whether or not overall patient well-being outcomes and light exposure rates differ between seasons.
16 (13 female, three male) participants from six residential homes in central Scotland were involved in this study. Over the course of one summer and one winter season, sleep patterns and well-being outcomes were gathered from all participants. Patients wore two body-mounted sensors to assess personal light exposure over the course of four days while also routinely completing cognitive assessments and visual tests.
Statistical associations were found between cognitive ability, sleep patterns, visual functions, and low levels of light exposure, regardless of the season. Analysis also found that the patients involved in this study did not receive appropriate amounts of light exposure in either season. Study participants became largely sedentary during the winter, leading the authors to suggest that residential homes work to increase in activity levels among patients during these months.
This study involved a relatively small group of participants within one specific geographical region (central Scotland). Overall participant well-being was assessed through a series of mostly verbal tests; no fluctuations in vital signs or bio-indicators were gathered.