Back in the early 2000s, the management team at Resolute’s La Doré (Quebec) sawmill noticed that the workers responsible for sorting lumber during the night shift were susceptible to making errors when they became drowsy. The job, performed in a seated position, demanded significant concentration as workers were tasked with evaluating the quality of 100 units of lumber per minute.
Mill manager Daniel Roy and superintendent Sylvain Bélanger and supervisor Dany Lamontagne became concerned about the workers’ safety and well-being, as well as the impact on the sawmill’s bottom line. Some workers, they realized, became especially drowsy because of the poor quality of sleep they were getting during the day. The management team contacted Susanne Julien, a representative of the local health agency. Ms. Julien put them in touch with a research team from Laval University led by Dr. Marc Hébert, whose work focused on sleep disorders.
Night-shift employees were invited to test a new device designed to adjust their biological clocks to the inversion of day and night. The lens of the device cut off blue light rays that are associated with daylight, thereby tricking the workers’ biological clocks into thinking it was nighttime and sending a signal to their brains that it was time to sleep. They were asked to place the device over their eyes in the morning right after completing their shift. Ronald Perron, who worked as a lumber sorter, remembers that the device helped improve the quality of his daytime sleep so that he could be more vigilant when working night shifts.
Today, the task of sorting lumber has become largely automated. Computers and artificial intelligence ensure 98% accuracy 24 hours a day.
While the results of the research study were encouraging and interesting, the effects varied from person to person. The study was eventually halted due to a scheduling change, but its findings were instrumental in the discovery that the human biological clock can only perceive blue in the light spectrum. That discovery led to the founding of Chronophotonix in 2006 by Dr. Hébert, who patented a device that emits alternating pulses of blue and red light, allowing the eyes to rest and leading to improved alertness, and increased safety and productivity for users.
Special thanks to Sylvain Bélanger for recalling the research study.
