Evening Light Intervention Before Night Shifts: Reduced Fatigue and Errors
Summary
This randomized controlled trial tested whether bright light exposure in the evening, before night shifts, could help nurses working rotating schedules. Fifty-seven nurses were assigned to either an evening light + morning light avoidance plan or a diet-modification plan. Over 30 days, those in the evening light group made 67% fewer work errors, compared to only a 5% reduction in the diet group. The light group also reported less fatigue and a small boost in mood. Both groups experienced modest improvements in fatigue, sleepiness, and sleep duration, but the evening light intervention had the clearest effect on error reduction and fatigue.
Why It Matters For Night Shift Workers and Night Owls
For people working rotating night shifts, fatigue often leads to mistakes and safety risks. This study shows that getting bright light in the evening before a night shift—along with avoiding morning light afterward—can reduce tiredness and cut down on work errors. While it’s not a cure-all, this is a practical strategy workers can use outside the workplace to help their bodies adjust, stay sharper on the job, and make night work a little safer.
Notes
Field‑deployable protocol.