Cavemen had plenty of things to worry about – lions, bears, starvation….. Today, in the digital age, we’ve got a different set of anxieties. One that is coming more and more into the spotlight is blue light.
Before the advent of artificial lighting, the circadian rhythms of all living things – the natural 24-hour wakefulness and sleep cycle which affects many biological processes – were attuned to the major source of light: the sun. People spent their evenings in relative darkness, a time of rest and recuperation, and rose with the morning sun, energized for the challenges of daily survival. But today, our evenings are filled with manmade illumination. Too often we are up at all hours and the rhythms of our bodies are all jangled up in pursuits no caveman could have fathomed.
The problem is that artificial light does not provide the full range of visible (red, orange yellow green, blue) and invisible (e.g., UV, infrared, gamma, etc.) light rays that our bodies were designed for. Rays on the red (warmer) end of the natural visible light spectrum have longer wavelengths, but less energy. Blue light rays, on the other (cooler) end, have the shortest wavelengths, yet provide the highest energy compared to other hues of the spectrum. Artificial lights contain no invisible rays and cannot replicate the full visible spectrum, though the old fashioned incandescent light bulbs and full spectrum fluorescents do a better job than the new energy-efficient LED (light-emitting diode) lights.
The concern is that LEDs, lacking the balance of the full sunlight spectrum, emit a disproportionate amount of blue light. The human eye is ill-equipped to block concentrated blue light from the very light sensitive retina. These high energy rays pass easily through the cornea and lens, reaching the retina. Over time, this has the potential to increase the risk of macular degeneration, eye strain, and more. Moreover, when artificial light and LEDs in particular are used at night, sleep also suffers, increasing risk of fatigue, depression, etc.
The LED screens of computers, electronic notebooks, smartphones, flat TVs and other digital devices, as well as most fluorescents, are what we are spending increasing amounts of time looking at and our bodies may be paying a price. Beyond the additional strain on eyes, many healthcare professionals are concerned that the toll being taken on the normal sleep cycle may be affecting melatonin and general hormone production, as well as other biological processes, possibly increasing the risk of serious metabolic disorders down the line.
What to do?
No need for panic. There are very sensible things you can do, once you acknowledge the situation:
- Avoid eye strain by breaking up your screen time. Try the 20-20-20 habit: every 20 minutes, take a 20 second break to look at something 20 feet away. Also, blink often. This refreshes eyes by reducing dryness.
- Pay attention to your body position at the computer. Sit in your chair, extend your arm so your palm is resting comfortably on the monitor; it should be about 20-26 inches away. Position the screen directly in front of your face – never tilted – and slightly below eye level.
- Get the right lighting. Reduce overhead and surrounding light; it competes with your screen and makes your eyes work harder to see. Use indirect light sources to reduce glare.
- Personalize your computer display settings. Bump up the text size. Adjust the brightness, not too bright or too dull and gray. On some devices you can even adjust the color temperature to reduce the amount of blue light emitted by a color display.
- Use dim red lights for night lights. Red light has the least power to shift circadian rhythm and suppress melatonin. For quality sleep, remove (or cover) other sources of bright light in the bedroom, like clocks, cable box screens, etc.
- Avoid looking at bright screens beginning 2 or so hours before bed.
- If you work a night shift or use a lot of electronic devices at night, you might consider getting a pair of blue-blocking glasses. These have glare-reducing, anti-reflective coatings that also block blue light. They are available for prescription or non-prescription lenses at stores specializing in optical needs. A well recommended brand is Featherwates Blue IQ lenses. Note: they are pricey and not really necessary for moderate night light exposure. These glasses should not be worn in natural daylight as blue light is an important part of the whole spectrum.
- Expose yourself to lots of natural bright daylight. This will enhance your ability to sleep at night and boost your mood and alertness during the day.
- There are now blue light filters available for smartphones, tablets, computers and other digital devices. Some examples: Eyesafe (Health-E), iLLumiShield, RetinaShield (Tech Armor), Retina Armor (Tektide), Frabicon and Cyxus. Free downloads for filters for some types of computers are available from Iris. Apple ipads have an adjustible brightness setting that blocks blue light.
- Get an eye exam. Talk to your doctor about how much time you spend in front of LED screens and possible symptoms of digital eye strain. Discuss ways of alleviating symptoms and protecting against harm.
- Eat a balanced, whole foods diet, especially many varieties and colors of vegetables which contain antioxidants and phytochemicals – like lutein, zeaxanthin, astaxanthin, anthocyanins, etc. – that are important for protecting the retina and overall eye health. Excellent “eye” food sources include: leafy greens, kale, spinach, broccoli, Brussels sprouts, orange peppers, organic pastured egg yolks, wild-caught Alaskan salmon, black currents, bilberry.
Modern life is a balancing act. We want to live in tune with Nature, but also stay in touch with a fast-paced, fascinating, increasingly energy-efficient world. LED lights are more energy-efficient than the old incandescents, but they have they’re caveats which can be managed. Like most everything in life, it’s about balance – something that has always been a challenge for human beings, even cavemen.
“Blue Light Has a Dark Side” – Harvard Medical Newsletter
Blue Light Exposed
Q & A: Why Is Blue Light Before Bedtime Bad for Sleep? – Scientific American
What’s in a Color? The Unique Human Health Effects of Blue Light – Environmental
How LED Lighting May Compromise Your Health – Dr. Mercola