Sleep and work functioning in nurses undertaking inpatient shifts in a blue‑depleted light environment
Summary
This study followed 25 nurses at a Norwegian hospital to see how working in a blue-depleted light environment (warmer light with less blue spectrum at night) compared with standard hospital lighting. Over two weeks in each setting, nurses wore activity trackers, kept sleep diaries, and rated their mood, stress, sleepiness, and caffeine use. The results showed very few differences: nurses felt slightly sleepier during evening shifts under blue-depleted light, while they drank a bit more caffeine during night shifts under standard lighting. Otherwise, there were no meaningful changes in sleep length or quality, stress levels, or mood. Nurses did report that the blue-depleted light felt warmer and more relaxing, but overall their sleep and functioning were about the same in both environments.
Why It Matters For Night Shift Workers and Night Owls
Light strongly affects alertness, and hospitals are experimenting with warmer “blue-depleted” lighting at night to support patient rest and possibly staff health. This study shows that nurses tolerated the lighting well, but it didn’t significantly improve their sleep or reduce stress compared to standard lighting. For workers, the takeaway is that lighting changes alone may not be enough to boost recovery or fight fatigue. Instead, the best results are likely to come from combining smarter lighting with other strategies—like better scheduling, protected breaks, and consistent routines.
Notes
Open access (BMC Nursing).