Employees often suffer from not getting enough quality sleep. This can harm work engagement and job performance. As a result, previous research has explored ways to improve sleep for employees, for example, by allowing flexibility in work scheduling or reducing the use of night shifts. However, such accommodations are not feasible for all organizations.
Other research on sleep and circadian rhythms has demonstrated that exposure to blue-light (a type of light emitted by technology such as smartphones and computer screens) can impact sleep patterns. On the bright side, wearing blue-light filtering glasses is a cheap and easy way to create “physiologic darkness” and reduce harmful influence on sleep patterns. Indeed, research has shown that wearing blue-light filtering glasses can improve sleep outcomes, but has yet to consider whether there are downstream effects on work-related outcomes.
BLUE-LIGHT FILTERING GLASSES AND WORK OUTCOMES
In this study, researchers (Guarana et al., 2020) conducted two experiments in which they provided a sample of employees with two pairs of glasses: one that filters blue light (the treatment pair), and one that does not (the control pair). Both pairs of glasses looked similar, and participants did not know which pair was the treatment and which was the control.
Participants were instructed to wear the glasses for at least two hours each night before going to sleep for a total of two weeks. Half of the participants wore the blue-light filtering glasses for the first week and the control glasses for the second week, while the other half wore the control glasses for the first week and the blue-light filtering glasses the second week. In addition, participants completed two surveys each day in which they recorded information about their sleep and work behavior.
RESULTS OF THE STUDY
The researchers found that wearing blue-light filtering glasses was associated with higher sleep quality and quantity compared to wearing the control glasses. While the results varied slightly across the two studies, in general, these improved sleep outcomes were in turn positively related to outcomes of work engagement, task performance, and organizational citizenship behavior (or “going the extra mile”), and negatively related to counterproductive work behavior.
Additionally, the researchers examined how an individual’s chronotype may influence these results. Chronotype refers to the time of day a person prefers to go to sleep relative to others. In one of their studies, the authors found that the beneficial effects of wearing blue-light filtering glasses were stronger for individuals with sleep periods later in the day (“night owls”) compared to individuals with sleep periods earlier in the day (“morning larks”). Furthermore, the researchers found that the positive effects of wearing blue-light glasses increased throughout the week, suggesting there may be a dosage effect of wearing the glasses.
PRACTICAL APPLICATIONS FOR ORGANIZATIONS
This research suggests that organizations may benefit from providing employees with blue-light filtering glasses, since doing so is an inexpensive intervention that may have downstream positive effects on performance. In addition, this intervention may prove most useful if it is targeted towards employees who consider themselves “night owls.” The authors also suggest that the positive effects of wearing blue-light filtering glasses may be even more useful for employees who work night shifts, although more research is needed to test this question directly.
Guarana, C. L., Barnes, C. M., & Ong, W. J. (2020). The effects of blue-light filtration on sleep and work outcomes. Journal of Applied Psychology. Advance online publication.