Marc Hébert can sympathize with the two Sûreté du Québec officers caught napping in a patrol car along Highway 40 near Trois Rivières one morning last month at around 7, an hour before the end of their overnight shift.

"It is quite normal to be very tired after a night shift," Hébert said. "At least they were not driving. Taking a nap would be the thing to do before hitting the road again."

He should know.

An associate professor in ophthalmology at Université Laval and an internationally renowned expert in depression-fighting light therapy and biological rhythms, Hébert has spent much of the past decade studying night workers and trying to develop ways to help them deal with the many mental and physical challenges of working unnatural hours.

The results of his latest study suggest he may have finally found an answer.

And the patent-pending method he's developed could help night workers lead healthier lives - and be more productive for their employers in the process.

"The main problem night workers face is fighting their internal biological clocks, which are trying to put them to sleep while they are performing duties that can be measured," Hébert said. "So we tried to trick those clocks into thinking night was day and day was night - and we were successful."

Carried out over two years at an AbitibiBowater sawmill in the Lac St. Jean region, the federally funded study focused on the dozen of the 185 workers at the facility who were responsible for grading wood.

Divided into three teams of four, the men rotated between night and day shifts at the mill, which operated around the clock Monday through Friday.

During night shifts, the men, whose job required them to sit long hours, were exposed to morning-like bluegreen light produced by two therapeutic lamps.

According to Hébert, who has a PhD in neurobiology and is president of the Society for Light Treatment and Biological Rhythms, an international organization that promotes research and clinical applications of light therapy and biological rhythms, the light slowed the production of melatonin, a hormone that "tells your biological clock it's night (and) time for bed."

That was confirmed, he added, by analysis of the men's saliva.

The same tests also showed that after five consecutive nights of exposure to light, the men's biological clocks had shifted two to four hours.

"That is substantial," Hébert said. "The goal isn't to create perfect night workers, like bats, but rather to help people remain alert through their shifts (and) get a good sleep later."

The brain-tricking charade was prolonged by the special glasses the men wore at the end of their shifts - and during the day when not sleeping.

The glasses cut blue light and other wavelengths that contain brain-waking photons.

"We only cut the part of the spectrum that their biological clocks could see," Hébert explained. "The men could function normally (and) actually see more colours, particularly all kinds of green."

The glasses enabled the men to drive home safely and not fall asleep at the wheel and cause an accident - or be forced to pull over and catch 40 winks roadside like the SQ officers did.

In addition to being a boon for public safety, Hébert said the men's answers to health questionnaires during the study, which was financed by Health Canada to the tune of $200,000, suggested the overnight therapy also helped them sleep and feel better.

The results were published recently in Progress in Neuro-Psychopharmacology & Biological Psychiatry, a respected international news and science research journal.

However, from a business perspective, the most telling results of the Université Laval study - which have not been made public until now - were the changes recorded in the men's performances at work.

According to Hébert, the effects of melatonin, which is produced in the pineal glands in the centre of the brain and goes directly into the blood system, increase during the night.

According to a recent report on the health effects of shift work by the Occupational Health Clinics for Ontario Workers - a reference document that is used and distributed by Statistics Canada - the result is ever-lower levels of concentration, alertness and motivation.

"This can slow a worker's reaction time and increase the risk of accident," the report says.

The nadir is reached between 5 and 6 a.m., when the biological clock - or circadian rhythm - reaches its lowest point.

According to Hébert, the error rates for lumber grading, which is done for both quality control and price calculation, were found to be five per cent at night and three per cent during day shifts.

By the fourth night of light treatment, however, he said the error rate of night workers had fallen to 1.5 per cent.

"That was an interesting and unexpected finding," Hébert said.

He calculated a potential savings of up to $4 for every 1,000 feet of board produced at the mill.

He said the preliminary findings of an ongoing project with the Quebec City police force is also showing beneficial results.

Now in its third year, the project involves the use of fast-pulsing blue lights in patrol cars during night shifts, as well as the post-shift use of special blue light-cutting glasses.

The equipment for the project is supplied by Chronophotonix, a company Hébert founded in 2006 that makes and commercializes custom solutions for night-shift workers.

"Many studies have shown that sleep deprivation causes all kinds of health and family problems," Hébert said.

He equated people suffering from sleep deprivation to being legally drunk - and pointed to studies that have linked disasters such as Three Mile Island, the Challenger space shuttle and the Exxon Valdez to sleep deprivation.

Night-shift work, he added, also results in lower employee retention, an increase in sick days and absenteeism, increases in workplace injuries and lower productivity.

"Most employers seem resigned to the fact these problems are unavoidable," Hébert said. "And there really is nothing on the market for night shift workers."

That's why he believes several companies - including trucking firms and Air Canada - have called to express their interest in his work.

"Night work's tough on people," said Martin Poulin, who supervises 16 shift workers who help produce 156,000 tonnes a year of sodium chlorate at the Magog plant of Swedish multinational Eka Chemicals.

According to Poulin, the company heard about Hébert from local medical researchers and invited him last year to give a presentation to employees on dealing with shift work.

Hébert also studied the lighting in the plant and came back with a proposal - which was accepted - to equip the workers with blue lightblocking glasses and to set up pulse lights near computer terminals the workers use to monitor operations.

Poulin said the workers have been wearing the glasses during night shifts since they arrived before Christmas, and are eager to see the lights installed this spring.

"The benefits aren't readily evident," Poulin said. "But the fact that the workers are using the glasses and seem excited about it is a good sign. If the guys didn't think there was anything good in it, (the glasses) would all be sitting on my desk - and that's not the case."

That's also why Hébert recently applied - together with Université Laval - for patents on some of his products and procedures in Canada, the United States, Europe and Australia.

"Night work poses huge challenges for companies and their employees," Hébert said. "We want to help provide solutions."