In the study, employees reported improvements in sleep duration in cooler, brighter lighting and control of light intensity and color temperature.
Office staff first spend three weeks in a randomly selected lighting environment and then in a new lab environment for the next few weeks. Employees in the control group received standard office lighting with an average illuminance of 500 lux and neutral white, whereas those in the test group received dynamic lighting of different color temperatures and intensities. These lights are tailored to the subject's age.
Researchers measuring the light close to the eyes found that the individualized staff showed higher levels of illumination in the morning and higher levels of color temperature near the tabletop and eyes.
It was reported that in the personalized group, the average sleep time was extended by 26 minutes.
To validate the findings, researchers will conduct further detailed analyzes to control for potential variables such as light sensitivity, general sleep quality and assessment period, and actual light irradiance measured with an optical recorder.
The current study is for reference only because it is inconclusive. However, this shows the importance of personalization.
Another finding is the diversity of light intensity and color temperature perspectives. The team reported that the findings "clearly demonstrated the need for personal control".
"We learned that even if personal controls happen by chance, users will enjoy the ability to set up lighting scenarios."
In the study, only a handful of participants realized that light had an impact on sensitivity, health, or productivity gains. Most participants will set the light to a comfortable level if controlled.