Blue light may fight fatigue around the clock

February 3, 2014
Credit: xiaphias/Wikipedia

Researchers from Brigham and Women's Hospital (BWH) have found that exposure to short wavelength, or blue light, during the biological day directly and immediately improves alertness and performance. These findings are published in the February issue of Sleep.

"Our previous research has shown that is able to improve alertness during the night, but our new data demonstrates that these effects also extend to daytime light exposure," said Shadab Rahman, PhD, a researcher in BWH's Division of Sleep Medicine and lead author of this study. "These findings demonstrate that prolonged blue light exposure during the day has an an alerting effect."

In order to determine which wavelengths of light were most effective in warding off fatigue, the BWH researchers teamed with George Brainard, PhD, a professor of neurology at Thomas Jefferson University, who developed the specialized light equipment used in the study. Researcherscompared the effects of blue light with exposure to an equal amount of on alertness and performance in 16 study participants for 6.5 hours over a day. Participants then rated how sleepy they felt, had their reaction times measured and wore electrodes to assess changes in brain activity patterns during the .

The researchers found that participants exposed to blue light consistently rated themselves as less sleepy, had quicker and fewer lapses of attention during the performance tests compared to those who were exposed to green light. They also showed changes in brain activity patterns that indicated a more alert state.

"These results contribute to our understanding of how light impacts the brain and open up a new range of possibilities for using light to improve human alertness, productivity and safety," explained Steven Lockley, PhD, neuroscientist at BWH and senior investigator of the study. "While helping to improve in night workers has obvious safety benefits, day shift workers may also benefit from better quality lighting that would not only help them see better but also make them more alert."

Researchers note that the next big challenge is to figure out how to deliver better lighting. While natural light is ideal, many people do not have access to daylight in their schools, homes or work places. In addition to improvements in daylight access, the advent of new, more controllable lighting technologies may help enable researchers to develop 'smart' lighting systems designed to maximize the beneficial effects of for human health, productivity and safety.

Explore further: Like coffee, blue light keeps night drivers alert

Related Stories

Like coffee, blue light keeps night drivers alert

November 23, 2012

(Medical Xpress)—Researchers from the Université Bordeaux Segalen, France, and their Swedish colleagues have recently demonstrated that constant exposure to blue light is as effective as coffee at improving night drivers' ...

Brighter light yields greater alertness

December 5, 2013

Do you sometimes feel tired when you're working in the office during the day? If so, some extra light could help. Research at TU/e shows that people immediately have more energy and feel alerter if there's more light. The ...

Recommended for you

Mobile app records our erratic eating habits

September 24, 2015

Breakfast, lunch, and dinner? For too many of us, the three meals of the day go more like: office meeting pastry, mid-afternoon energy drink, and midnight pizza. In Cell Metabolism on September 24, Salk Institute scientists ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.