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.

由于我们的社交行为，人们至少将80％的时间都花在室内，其中大部分是在人造光下。在研究和建筑设计中，日光被认为是宝贵的资产，因为它是免费的优质光线的主要来源，并建议对人的行为，健康和睡眠质量产生积极影响。随着年龄的增长，人口中的睡眠质量越来越差，这影响了至少50％的老年人口。关于睡眠干扰的研究发现，尤其是在老年人中，睡眠中断会影响机敏性，认知能力和情绪。这增加了跌倒的风险，增加了疲劳并减少了其他一些心理功能。暴露在日光下（室内和室外）可减少睡眠中断。参加体育锻炼和睡眠质量评估的是32位独立居住在英国的参与者，年龄在65至95岁之间。由于夏季和冬季的日光利用率差异很大，该研究分为两个季节。在每个季节中，参与者都要完成匹兹堡睡眠质量指数（PSQI）问卷，早睡时间问卷（MEQ）和为期7天的睡眠日记/日志活动。确定在户外度过的时间。预计在夏季和冬季报告较少暴露于白天的参与者将报告较差的睡眠质量。但是，事实并非如此。夏季和冬季之间的主观睡眠质量没有很大差异，即使不同季节的日光照射差异很大。这项研究探讨了两个不同季节的日照量与人们的表型，身体活动和睡眠质量（参与者之间和参与者内部）之间的关系。该信息对于找到支持人口老龄化的手段至关重要。

实际应用：在建筑环境中，日光是要考虑到乘员健康和福祉的重要特征。这项研究为伦敦活跃的老年人在两个季节内暴露的日光量及其对他们的整体睡眠质量的影响提供了真实的见解。研究结果表明，暴露于日光下可以通过减少夜间醒来次数，使65岁以上睡眠质量较差的人受益。这项研究为了解日光照射如何影响人们提供了一个步骤，并可用于为老龄化人口提供住房设计信息。