Researchers from the « sleep, attention and neu-ropsychiatry » Laboratory ( CNRS / University Bordeaux Segalen ), in collaboration with Swedish scientists, recently demonstrated that a continuous emission of blue light is as effective as coffee to improve alertness and thus safe driving at night, for the first time in driving tests. Published in the journal PLoS One, these findings could lead to the development of an anti-drows-iness electronic system integrated into vehicles. More scientific examination is necessary to test this and other benefits of the device. Induced by sleep deprivation, drowsy driving at night reduces alertness, reflexes and visual perception of the driver. It is the cause of one third of fatal accidents on motorways.

Besides the opportunity to take a nice « powernap » with the light emitted by the PSiO ® and avoid an accident on the highway, the PSiO® acts as an alternative to coffee or other biochemical stimulants that have harmful side effects. It is known that blue light increases alertness by stimulating special nerve cells in the retina, the membrane localized at the back of the eyes : the ganglion cells of the retina ( IRGC ). These cells are connected with the
areas of the brain that control our ability to stay awake. Their stimulation by an exposure to blue light halts the secretion of melatonin, the hormone responsible for decreased alertness at night. The positive effect of blue light on the nocturnal vigilance has been known since 2005, thanks to American studies. But these studies were conducted only during simple cognitive task s, like pressing a button if one perceives a light stimulus. Driving is a much more complex task.

To study the effectiveness of blue light during night driving, researchers have thought to test it in the cockpit of an experimental vehicle, where a special LED lamp was mounted on the central dashboard, emitting continuous blue light. Then they asked 48 healthy male volunteers of an average age of 33.2 years to drive for 3 nights with a break of at least a week between tirals, for 400 km on the highway.

The driving period was always between 1 am and 5:15 am, with a 15 minute break halfway through. During each of the 3 nights, each volunteer received either continuous exposure to blue light, or two cups containing 200 mg of caffeine, before departure and during the break. They were also tested for placebo effects on the third night with two cups of decaffeinated coffee.

It is important to note that their sleep was not affected after driving under continuous emission of blue light. The researchers then analyzed a criterion that reflected a decrease in vigilance : the number of inappropriate line crossings side ( emergency lane and overtaking line).


It appeared that the average number of inappropriate crossing was 15 with blue light, against 13 for coffee and 26 with placebo. Continuous exposure to blue light while driving is, therefore, as effective as coffee to fight against drowsy driving as long as the driver is not bothered by this light. Indeed 8 of 48 volunteers ( 17% ) were dazzled by blue light and could not perform the test.

Scientists are now stepping up to verify that these initial results can be reproduced on a larger number of men, but also women and elderly people. One application could be the design of an antidrowsiness embedded system in the vehicle. One imagines that the implementation of a vigilance maintenance system will take time for manufacturers of trucks and cars. Moreover, the effect of the « PSiO® POWERNAP » is not only defined by the projection of blue light ( with the right wavelength of 470 nm ) but also the immediate peace of mind. A complete shutdown of neurons is welcomed to allow the brain areas assigned to monitoring the road to be able to rest especially after driving for over 5 hours!

So our advice is : use the PSiO® when traveling by car, particularly on long journeys that take you on vacation!

Nocturnal In-Car Blue Light Exposure Improves Driving Motorway : A Randomized Controlled Trial. Jacques Taillard, Aurore Capelli, Patricia Sagaspe, Anna Anund, Torbjorn Åkerstedt Peter
Philip. PLoS One, October 19, 2012.

It is known that blue light increases alertness by stimulating special nerve cells in the retina. After experimentation, continuous exposure to blue light while driving is as effective as coffee to fight against drowsy driving.