The latest news alert for tech aficionados is this: Blue light from digital screens is hazardous to your health. Recent scientific studies have demonstrated that blue light emitted by the screens on cell phones, tablets, televisions and computers may be making it harder for us to sleep.
blue light
Each of us has a master clock built into our bodies. That clock has a circadian rhythm that coordinates with the Earth’s 24-hour rotation cycle which causes the Earth’s light-dark cycle. Light sensitive cells in the eye’s retina send information to the brain’s master clock, which readjusts daily. The darkness at night tells our natural clocks to produce melatonin, a hormone that reminds us to sleep every night.
Now, however, we are finding that the lighted screens on our computers, tablets, televisions, and smartphones is interfering with our sleep cycles. Experts agree that certain wavelengths of light from the blue end of the spectrum can disrupt our circadian rhythms. The suppression of melatonin caused by too much blue light after dark can prolong the time it takes to fall asleep, which in turn can delay the peaceful REM sleep that we need to feel truly rested. It can even reduce alertness the following morning. Some studies say they excessive blue light may even be damaging our retinas and increasing the risk of age-related macular degeneration.
Yet experts like those published in the Frontiers in Public Health, found that many manufacturers are increasing the amount of blue light produced by their products in order to keep people more alert and more productive. They are making screens bigger, brighter, and bluer. To save money, some television manufacturers are producing screens with LED backlighting that is heavily skewed toward the blue end of the spectrum.
All of this, of course, adversely affects our circadian clocks and melatonin production when these devices are used after dark. Ironically when our eyes detect more blue light at night, this can affect our sleep which in turn can adversely affect both daytime and after dark productivity.
There is another concern. Since blue light is focused in the front of the retina, when viewing screens with a large amount of blue light, the eye must constantly try to maintain its focus which adds significant pressure to the eye’s energy expenditure causing eye strain
Years ago, I tried wearing computer glasses from two different companies. These were created to block out harmful light rays. I found that these glasses eased the eyestrain that I suffered from constant computer use. I was sad when both of those companies went out of business. Their products were obviously before their time.
Now, however, things have changed. After many scientific studies confirmed this link between blue light and sleep, several manufacturers including Acer, Apple, and Amazon are taking action. They are not lowering blue light transmissions on an overall basis, but are instead inserting a new feature that can automatically lower the blue light transmissions when the sun goes down.
Apple’s latest mobile operating system, iOS 9.3 includes what they call a “Night Shift” feature. This feature will automatically lessen blue light and increase the more benign yellow light after dark. You can manually enable Night Shift’s automatic mode or set your own Night Shift schedule. Just open the Settings and tap on Display & Brightness, then tap on Night Shift. There you can manually enable it or set a scheduled time to turn it on and off. You can also set the intensity of the color temperature change. When Night Shift is enabled you will see an obvious yellowing of the screen.
blue light
Amazon in their latest mobile operating system, Fire OS Bellini, has added a feature called “Blue Shade”. Amazon says that using specialized filters, this new Blue Shade minimizes blue light and automatically adjusts and optimizes the back light for a more comfortable nighttime reading experience. With Blue shade, the blue wavelength light is always sufficiently suppressed so you can read in bed without giving up a good night’s sleep. This is especially noticeable in dark rooms. Using Blue Shade when viewing the screen in dark rooms produces an ultra-low brightness that still allows the user to read text comfortably. To access Blue Shade, just tap on the Fire’s Quick Actions menu.
Acer has also entered the blue light management area with Bluelight Shield, an application that allows users to control how much blue light is used to display an image. This allows users to lower levels of blue light to lessen the negative effects of blue light exposure. You can adjust Acer Bluelight Shield settings using the Acer Quick Access application.
blue light
Many computer monitors now have pre-sets for blue light management. BenQ was one of the first to promote a way to turn down the blue light emissions. Asus and ViewSonic followed suit. The presets for blue light control are called different things by different manufacturers. Philips has a preset called “SoftBlue”. Samsung has one called “Warm2”. Others have settings called “Warm” or “Reading”.
For monitors that don’t have presets, there are programs like F.lux that can automatically reduce blue light when it gets dark according to your local time zone. There are F.lux versions available for Windows, Mac, Linux, and some Android devices.
There are currently several manufacturers like Adlens making glasses that protect against blue light. Essilor, a leading manufacturer of lenses for prescription glasses has included blue light protection in several of their popular Varilux, Eyeze, and Transitions lenses. Many companies are also making blue light screen protectors.
Ten years ago only forward-thinking adventurous manufacturers were concerned about the damaging effect of blue light on our eyes. Now, it seems that everyone has jumped on the bandwagon.  It is wonderful to see the concern. Having good eyesight is a precious gift. We all need to do everything we can to protect our eyes.