Blue-toned lights 'help workers'

Researchers found blue-enriched lights improved mood and performance

Changing white office lights to a blue-toned shade can help workers stay alert and feel less sleepy during the day, researchers have found.

A study at the University of Surrey's Sleep Centre found blue-enriched white light improved mood and performance.

It also helped reduce fatigue in the evening, irritability and eye strain and improved ability to concentrate, with some workers even sleeping better.

Research was carried out on 104 white-collar workers on two office floors.

This research may indeed imply that our currently used artificial office lighting is suboptimal

Professor Derk-Jan Dijk

Every participant was exposed to two lighting conditions, each lasting four weeks, professor Derk-Jan Dijk said.

He said questionnaires were used to assess alertness, mood, sleep quality, performance, mental effort, headache, eye strain and mood during the eight-week study

The research scientist said the blue-enriched white light was thought to be more effective because it targeted a recently discovered "photoreceptor" in the eye.

But he said: "This research may indeed imply that our currently used artificial office lighting is suboptimal for maintaining alertness. "

The research was published in the Scandinavian Journal of Work, Environment and Health.