LRC Releases Survey Results on Daytime Light Exposure
The Lighting Research Center (LRC) at Rensselaer Polytechnic Institute, Troy, N.Y., recently released the results of a survey that investigated the impacts of working from home or quarantining indoors due to the COVID-19 pandemic on individual daily light exposures — and how this may be affecting sleep quality and psychological health. In May 2020, it invited people who had been staying home due to the pandemic to complete a short survey about their sleep, mood, and daily light exposure, and 708 responded.
LRC researchers analyzed the data to understand how daily indoor light exposure, time spent outside, and time of day spent outside affected sleep quality, sleep-related impairment, anxiety, stress, depression, and mood. Of the respondents, only those who were unemployed and staying at home (or employed and working from home) were included in the analysis, which totaled approximately 600 people.
According to a press release from the organization, the results revealed that daily indoor light exposure and time spent outside had a major impact on all survey outcomes, including sleep disturbances, sleep-related impairment, anxiety, stress, depression, and mood. Compared to people with “somewhat dim” to “very dim” indoor lighting, people with “somewhat bright” to “very bright” lighting, including having windows without (or with open) curtains or shades, or having several lights turned on, reported:
- Fewer sleep disturbances
- Less anxiety and depression
- Feeling less tired or less irritable
- Feeling generally happier and more positive
- Less sleep-related impairment
“Sleep quality and mood significantly improved when people spent the majority of their time in a brighter, compared to dimmer, location in their homes,” said LRC researcher Charles Jarboe, who led the study. “If you can add a little more light to your space during the day — one extra lamp, or open your window shades, for example, it could help you feel better, and improve your sleep.”
Another especially important factor was the amount of time spent outdoors. The survey results revealed that people who spent one to two hours outdoors each day reported feeling significantly less anxiety, stress, and depression, and reported sleeping better than those who spent less than 30 minutes outdoors each day. The impact leveled off after two hours, however. Morning light provided the greatest benefits.
The survey results also revealed slightly higher than average overall scores for anxiety. Given the extraordinary nature of the coronavirus pandemic, there are many factors that contribute to psychological and emotional health outcomes that are more severe than in normal circumstances. However, for all outcome measures, the strong trends exist that one would normally expect in relation to overall light exposures and time spent outside during the day, indicating that our daily habits and establishment of a robust 24-hour light-dark pattern has a significant impact on our health and wellbeing, even during trying times.
It is also worthy of note that a potential benefit of working or quarantining at home is that individuals can have more control over their environment, such as setting up their workspace facing an open window. Individuals can also benefit from flexibility in their work schedule, and can choose to work or take breaks outside, which may not be an option when working at the office. These factors can increase daily light exposure, which has many benefits, as revealed in the survey.
For more information on the results of this survey and how light impacts proper sleep, read the original press release from the LRC.