Correlated color temperature and light intensity: Complementary features in non-visual light field

The effect of blue light on cognitive function at workplaces: A systematic review

AIM

Due to the widespread use of artificial lighting in modern workplaces, exposure to blue light is becoming increasingly common. Blue light, known for its shorter wavelength and higher energy, has been linked to both positive and negative effects on cognitive functions and well-being.

OBJECTIVE

This systematic review explores the impact of blue light exposure on cognitive performance and sleep in various workplace settings.

MATERIAL AND METHODS

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Using predefined inclusion and exclusion criteria, the team searched three reputable databases (PubMed, Web of Science, and Scopus). Two authors independently screened the search results and the three other authors performed the data extraction and validation from the selected documents. The quality of the articles was assessed using the quality assessment checklist provided by The Joanna Briggs Institute (JBI).

RESULTS

From an initial set of 63 articles, 29 documents met the inclusion criteria. The findings reveal that blue light, particularly at high color temperatures and intensities, enhances cognitive functions such as attention, alertness, and reaction time. However, its effects on memory and sleep were more variable. Exposure to blue-enriched light was consistently associated with improved workplace performance, although some studies reported a mixed or insignificant impact.

CONCLUSION

This review underscores the potential benefits of blue light in workplace settings, particularly for enhancing attention and reaction times. However, variations in study outcomes suggest the need for standardized lighting interventions and further research on its long-term cognitive impacts.

The Complex Effects of Light on Metabolism in Humans

Light is an essential part of many life forms. The natural light–dark cycle has been the dominant stimulus for circadian rhythms throughout human evolution. Artificial light has restructured human activity and provided opportunities to extend the day without reliance on natural day–night cycles. The increase in light exposure at unwanted times or a reduced dynamic range of light between the daytime and nighttime has introduced negative consequences for human health. Light exposure is closely linked to sleep–wake regulation, activity and eating patterns, body temperature, and energy metabolism. Disruptions to these areas due to light are linked to metabolic abnormalities such as an increased risk of obesity and diabetes. Research has revealed that various properties of light influence metabolism. This review will highlight the complex role of light in human physiology, with a specific emphasis on metabolic regulation from the perspective of four main properties of light (intensity, duration, timing of exposure, and wavelength). We also discuss the potential influence of the key circadian hormone melatonin on sleep and metabolic physiology. We explore the relationship between light and metabolism through circadian physiology in various populations to understand the optimal use of light to mitigate short and long-term health consequences.