Industrial Safety

Putting the night shift to bed


Nov 02, 2009

Chronobiology International — Informa Healthcare’s journal on how biological rhythms affect the systems of living things — has published a new study that shows how the use of blue light blocking eyeglasses can help facilitate daytime sleep for shift workers.

The study recruited permanent night-shift workers from Canada Post’s distribution center in Quebec City. The study used two groups — a summer group and a fall/winter group — in order to reduce the chances of the results being affected by seasonal daylight differences. Both groups were asked to wear specialized blue light blocking glasses when out of doors. The glasses were designed by the team to block the transmission of blue light because this is the portion of the light spectrum that most effects the body’s circadian clock and sleep-wake rhythm. They also wore light monitors on their wrists.

Both groups obtained 30 minutes more sleep within the same time in bed, suggesting fewer awakenings and better sleep efficacy.

A good day’s sleep for those who work through the night is not just about getting enough beauty sleep or feeling less grumpy upon waking. It’s about the health of the worker and the safety of those around him.

Blue blockers could be the new ‘black’ in dark glasses.