Bright Environmental Light Reduces Post‑Shift Sleepiness in ICU Nurses
Summary
This crossover randomized trial tested whether bright environmental lighting could help ICU nurses stay alert during 12-hour night shifts. Forty-three nurses worked under either standard hospital fluorescent lighting or high-intensity white light (1,500–2,000 lx) for 10 hours. Under bright light, nurses reported less sleepiness at the end of their shift. However, they also showed more errors on psychomotor vigilance tests, suggesting that while alertness improved, sustained attention performance did not.
Why It Matters For Night Shift Workers and Night Owls
This study shows that brighter lighting can reduce feelings of sleepiness during long night shifts, which may help staff feel more awake on duty and safer when heading home. At the same time, the increase in performance errors highlights that light is not a complete solution for fatigue. For hospitals and night-shift workers, the takeaway is that light exposure can be one useful tool, but it should be combined with other fatigue management strategies — like naps, recovery time, and smart scheduling — to truly improve safety and performance.
Notes
ICU setting; objective and subjective measures.