When we refer to light, we are referring to the tiny part of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation consists of an enormous range of wavelengths and frequencies, but visible light exists in the range of ~400-700 nm. At the upper end of the spectrum is where we see blue light.
This comes from a high energy wave that works both with and against us. This light has been shown to boost alertness, help memory and cognitive function and even elevate mood. It is even used to treat seasonal affective disorder (SAD), a type of depression related to the cooler seasons where we expose ourselves to less sunlight, the largest source of blue light in our day to day lives. During the day, blue light from the sun hits melanopsin receptors in our bodies and causes a release of enzymes that ultimately bring melatonin levels down by inhibiting their release, and waking us up as a result, which is great! Melatonin is a sleep-promoting hormone secreted by the Pineal Gland in our brain that maintains the body’s circadian rhythm and helps regulate other hormones, all of which are integral in getting our body up and lively.
Conversely, when this high energy light doesn’t dim towards the end of the day, our body’s intrinsic biological clock, or circadian rhythm is thrown off. It is still so stimulated by the light it assumes is suggestive of daytime that it doesn’t know to increase the release of melatonin to trigger our body's drowsy, slowed down state. Without this regulation, we are left in something of a perpetual jet lag. But unlike the short-lived repercussions of travel jet lag, this particular state is chronic, and its negative effects have snuck into our daily living to become our new normal. But the effects of this lagged living goes beyond just minor fatigue and inconvenience. Poor sleep has been associated with impaired glucose metabolism, obesity, increased risk of heart disease and stroke, slower memory recall, concentration deficits, the aforementioned depression and a whole host of other symptoms not at all contributing to optimal living but more in our control than we give ourselves credit for.
Artificial blue light is associated with LED and screen-based OLED illumination, meaning our laptops, tablets and mobile phones are all sources of its emission. Sunglasses and welding helmets are specifically designed to block light in this range, but the tech industry is only now adjusting. With Americans devoting 10+ hours to screen time a day, it is no surprise that our eyes feel fatigued, dry, itchy, and accompanied by a headache more often than usual. Adult eyes also retain the effects of light with age and this cumulative effect causes immense strain, unnecessary exhaustion, and rapid decline of vision. Because of its temperature and frequency, blue light has been linked to early-onset Advanced Macular Degeneration, and consistent and consequential melatonin disruption has been linked to an increased risk of obesity and even some cancers. And with screen usage in children rapidly rising in this day and age, we have an even bigger problem on our hands. Up until the age of 14, the crystalline lens of the eye is more transparent to blue light energy waves and therefore children are at special risk when constantly in front of a device. Increased and prolonged exposure to high energy visible light (HEV) has been linked to increased diagnoses of nearsightedness among children.
So here’s how to protect yourself from the negative effects of blue light:
Glasses and contacts - make future optometry purchases with specialized HEV filters/coatings. This is the best option if you’re on devices all day long, or have to consistently wear visual aids. You can also purchase dedicated blue light blocking glasses. TrueDark is a company created by Dave Asprey himself and sells several variations of the glasses depending on your taste, most of which block up to 40% of blue light. But they even produce a special pair of night-time glasses to wear overtop of your prescription glasses for an hour before bedtime to block out 100% of blue light from everything from devices to streetlights, for optimum sleep.
Laptop/Desktop - Download an App called Flux to automatically regulate your computer screen’s bright blue display as the sunsets. It does result in an eerie yellow screen that takes time to adjust to, but improved health and rest are worth it.
Your home - When walking around at night, use the flashlight on your phone at a low setting, or the glow from your phone screen if that is functional enough to help you maneuver in the dark. Sleep disruption for bathroom usage or late-night snacking is bad enough without the harsh blast of room lights to force you awake and tarnish the remainder of your night of rest. Or better yet, add dimmer switches to your main rooms to allow light adjustment.
Mobile Devices - And finally, the biggest culprit. iPhone users can now use Night Shift (under settings > display) and the less popular colour tint feature, while Android users can download the app Twilight for the same result. Experiment with switching out your late-night scrolling and video watching to listening to a book or podcast or ambient (screen face down). Or better yet, reading an actual book. Focussing on reading a hard paper or having to rely solely on audio feedback will relax your brain into an easy slumber and release from insomnia.
While these changes may seem tedious, only a blue-light free experience can remind us of how efficiently our bodies were meant to function. The slow decline of our health and things like frequent headaches, dry eyes, poor concentration, impaired memory, weight gain, etc can easily be swept under the rug as par for the course, but this should not be the case. Listen to your body's quiet red flags, make adjustments accordingly, and lets return to the super human state we were born for.