We rely on sunlight and the lack of it to ‘tell’ our bodies when it’s time for wakefulness and for sleep. It’s responsible for our circadian rhythm, which is essentially a 24 hour wake/sleep pattern of our biological functions. The 24 hour cycle of sunlight and darkness keeps everyone’s ‘internal’ clocks synchronized in a particular geographic location.
If you fly to another part of the world, your circadian rhythm eventually adjusts to the day/night cycle of the particular locality. It turns out that the blue-green part of sunlight is responsible for setting our clocks. If you expose someone to this light after sunset, it resets or fools the person’s internal clock into behaving as though it’s daytime. This increases alertness in someone who would otherwise feel drowsy. The effect is further enhanced by consuming caffeine.
This is the finding of a study made by Dr Shamsi Shekari of Queensland University of Technology. The study was conducted on 18-25 year old drivers who chewed caffeinated gum while wearing commercially available light therapy glasses that emitted blue-green light. It was found that the caffeine and light therapy worked better together than either alone.
Does this mean you should put on light therapy glasses and chew caffeinated gum the next time you feel drowsy on the road? If you’re feeling drowsy during a sunny day, then the light from the glasses probably won’t matter. Falling asleep during the day occurs when you’re extremely sleep deprived. However, if you had plenty of sleep the night before, and you’re getting drowsy while night driving, it might be worth trying.
Wear the glasses at a rest stop, not while driving. These glasses aren’t designed for driving and may interfere with peripheral vision. In addition, the bright blue-green light from the glasses may have an adverse effect on your night vision.