Effects of long-term exposure to stroboscopic effect from moderate-level modulated light

Abstract

The effect of a 13-week exposure to moderate levels of light modulation resulting in visible, but not irritable, stroboscopic effect was studied. Over the course of three months, two sets of participants working in an office environment filled in a questionnaire about their health and wellbeing at the start and the end of each working day. Using a schedule of changes between two light settings differing only in the amount of temporal modulation, it was shown that the higher temporal modulation light did not significantly increase the occurrence of any health and wellbeing parameters (like eyestrain and headaches) tested. Furthermore, even though there was a large variation in the individual probability of complaints, there was no interaction effect between the individual level of complaints and the amount of light modulation. Using power analysis, we demonstrate that the increase of unwanted effects of 5% or more has a probability of less than 5%.