A 2026 study published in The Journal of the Illuminating Engineering Society is adding a new layer to the conversation about lighting design—one that electrical contractors and electricians working in commercial environments may want to pay close attention to. The research explored whether lighting conditions influence people’s self-reported mood, perception and health symptoms. Twenty-eight participants took part in the study, working in pairs inside a controlled room under two different diffused-light conditions: variable daylight and static artificial lighting. The test environment was designed to remove visual cues such as windows or outdoor views. Participants could not tell whether the light they were experiencing was coming from daylight or an electric system. Both lighting conditions met current circadian-oriented lighting guidance and delivered strong daytime illumination levels. The results revealed a clear difference at: Design Research Looks at How Lighting Affects Mood – Electrical Contractor Magazine