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Cited by 12Sleep and related disordersCircadian rhythm and melatoninSleep and Work-Related Fatigue

Assessing the impact of daylight exposure on sleep quality of people over 65 years old

Open access
Flores-Villa, Lorna, Unwin, Jemima, Raynham, Peter·2020·Building Services Engineering Research and Technology
DOI 10.1177/0143624419899522
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Abstract

Due to our social behaviours, people spend at least 80% of their time indoors, mostly under artificial light. In research and building design, daylight is considered a valuable asset because it is the primary source of free, good quality light and it is suggested that it has a positive influence on human performance, health and sleep quality. There is a tendency in the population for increasingly poor sleep quality with age, and this affects at least 50% of the elderly population. Research on sleep disruption has found that especially in the elderly population, interrupted sleep can affect alertness, cognitive performance and mood. This increases the risk of falls, increases fatigue and reduces some other mental functions. Exposure to daylight (indoors and outdoors) is expected to reduce sleep disruption. Physical activities and sleep quality were assessed using 32 participants living independently in the UK, aged between 65 and 95 years old. The study was divided into two seasons due to a considerable difference in daylight availability in summer and winter. In each season participants completed the Pittsburgh Sleep Quality Index (PSQI) questionnaire, Morningness–Eveningness Questionnaire (MEQ) and a seven-day sleep diary/log activity; where time spent outdoors was identified. It was expected that participants who reported less exposure to daylight during summer and winter would report worse sleep quality. However, this was not the case; subjective sleep quality did not differ greatly between summer and winter, even though exposure to daylight varies greatly between seasons. This study explores the relationship between exposure to daylight throughout two different seasons and people’s chronotypes, physical activities and sleep quality (between and within participants). This information is essential to find means of supporting an ageing population. Practical applications: In the built environment, daylight is an important feature to consider for the occupant’s health and wellbeing. This research provides real-world insight into the amount of daylight that active aged people are exposed to during two seasons in London, and how this could impact their overall sleep quality. The findings suggest that exposure to daylight could benefit people over 65 years old with poor sleep quality by reducing the number of awakenings during the night. This research provides a step towards understanding how daylight exposure effects people, and can be used to inform housing design for the ageing population.

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  • Reduced exposure to natural light due to more time spent indoors, lack of physical activity during daylight hours, poor indoor lighting and nighttime light exposure exacerbates these issues.

    “Reduced exposure to natural light due to more time spent indoors, lack of physical activity during daylight hours, poor indoor lighting and nighttime light exposure exacerbate these issues [15, 31, 32, 33].”

    From Ocular light exposure interventions for sleep, circadian rhythms, rest-activity cycles, mood, and cognitive function in older adults: An Overview of Cochrane and non-Cochrane Systematic Reviews (2025) · cites this paper as [32]

    The Abstract (page unavailable) says people spend much of their time indoors and suggests daylight may benefit sleep; the Introduction (page unavailable) reports that older adults’ homes tend to be poorly lit. But the paper does not establish that lack of daytime physical activity or nighttime light exposure exacerbates the issues, and its Discussion says daylight exposure did not make a difference in this group’s subjective sleep quality. (LLM, conf=0.86)

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Research works printed but not linked: 1

  1. Boyce PR. Non-Image-Forming System. In: Human Factors in Lighting, Third Edition. 3rd ed. CRC Press; 2014. p. 91-112. Available from: https://doi.org/10.1201/ b16707. · DOI

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Authors
Flores-Villa, L., Unwin, J., & Raynham, P.
Affiliations
  • University College London (GB)
  • Institute for Environmental Design and Engineering, UCL, London, UK
Corresponding author
Flores-Villa, Lorna
ORCID
Venue
Building Services Engineering Research and Technology
Publisher
SAGE Publications
Published
2020-01-21
Volume
41
Issue
2
Pages
183-192
ISSN
  • 0143-6244 (ISSN-L)
  • 1477-0849
DOI
10.1177/0143624419899522
OpenAlex
W3003031787
Cited by
12
References
21
Citations by year
2026: 1 · 2025: 5 · 2024: 4 · 2023: 1 · 2021: 1
FWCI
0.48
Type
journal article
Language
en
Open access
Licence
journals.sagepub.com/page/policies/text-and-data-mining-license (tdm)
Locations
  • Building Services Engineering Research and Technology (publishedVersion)
  • UCL Discovery (University College London) (submittedVersion)
Topics
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and related disorders
  • Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Circadian rhythm and melatonin
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and Work-Related Fatigue
Keywords
daylight exposure, sleep quality, older adults, chronotype, physical activity, seasonal variation, indoor lighting, sleep disruption, built environment, population aging

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