Harmful Effects of Blue Light and How to Protect Yourself

It’s no secret that blue light is everywhere. We identify the harmful effects of blue light as well as how you can protect yourself during exposure.

We expose ourselves to various forms of blue light—from natural sunlight to indoor fluorescent lighting to device screens—every day. Blue light does have its benefits, such as its abilities to boost attentiveness and set our bodies’ circadian rhythms and biological clocks. However, the harmful effects of blue light can significantly affect the body.

Why Should We Be Aware of Blue Light?

The light we see is composed of varying wavelengths. In essence, each color of light—red, orange, yellow, green, and blue—has a different effect.

Blue light, or high-energy visible (HEV) light, has a short wavelength and high energy. Of all the different types of light the human eye can see, blue has the most powerful (and most detrimental) effects on eye health—on the energy spectrum, blue light is close to harmful UV light.

Digital Eye Strain

An obvious symptom of blue light exposure is Computer Vision Syndrome (CVS), or digital eye strain. In fact, the Vision Council states that 59% of American adults confirmed experiencing symptoms after using electronic devices. Symptoms of digital eye strain include headaches, blurry vision, and ocular pain. This discomfort can last for hours. However, positioning screens at an arm’s distance away from you and wearing the proper eyewear can alleviate any pain.

Retinal Damage

Our eyes can’t effectively block blue light because the eye’s natural filters cannot limit light absorption. Blue light passes through the cornea and lens and damages the retina, or the inner lining of the back of the eye. The light prematurely ages the eye and can cause vision-related issues such as macular degeneration, or the gradual breakdown of cells behind the sensitive tissues in your eye. This can eventually lead to vision loss.

Sleep Disruption

We need sleep to function at our best—and evening light exposure is robbing us of it. Light acts as a stimulant by interfering with melatonin production. Falling and staying asleep is harder because your brain isn’t receiving a cue to prepare for bedtime. Rather than exposing yourself to light at night and thus hindering your sleep, make sure you receive enough sunlight during the day, which may help you sleep better. Blue light, principally around 460–480 nm, suppresses melatonin biosynthesis, directly proportional to the light intensity and length of exposure of blue light. Many LED lights in use today, which have replaced incandescent light bulbs, generally give off more blue light than incandescent bulbs. Blocking blue light a couple of hours before bedtime may be an important method to avoid insomnia.

How to Protect Yourself Against the Harmful Effects of Blue Light

Limit screen time at night, and avoid looking at bright screens at least two hours before bed.

If you must use a computer for work, take frequent breaks. A great exercise from the American Optometric Association is the 20-20-20 rule: “Take a 20-second break to view something 20 feet away every 20 minutes.”

Use a blue light filter app on your computer, phone, and tablet. These apps make your screen appear orange, which should be easier on the eyes.

You can also purchase quality glasses that feature orange- and yellow-tinted lenses, which block and absorb all light from the blue spectrum.

Lutein and zeaxanthin are pigments that offer natural protection from blue light. To reap these amazing benefits, consume leafy greens such as kale and spinach.

Finding the Right Combination of Light?

It’s likely there is a happy medium between excessive blue light and lack of light in the winter when people suffer Seasonal Affective Disorder. One of the treatments for Seasonal Affective Disorder (SAD) includes light therapy or phototherapy.

The specific cause of seasonal affective disorder is unknown, but may be related to circadian rhythm or the seasonal biological clock, when reduced level of sunlight in fall and winter may cause winter-onset SAD. The decrease in sunlight may lead to feelings of depression.

Reduced sunlight can also cause a drop in serotonin which may trigger depression. A drop in serotonin can cause depression, poor memory and a number of other symptoms.

Melatonin levels can be affected by the change in season, which can disrupt the balance of the body’s level of melatonin, which may cause sleep disorders.

There is probably some wisdom in adjusting the proper timing sequence and exposure duration of blue light for optimal health for the eyes and sleep.

Some lights designed for phototherapy for SAD deliver 10,000 lux (very bright light) and are in the 5000K spectrum (K stands for Kelvin). When the color temperature is 5000K or higher, the light produced appears bluish white, and is also known as simulated daylight. Indoor plants also grow better with light in the 5000K or higher color temperature range.

When the color temperature is 2700K, the light produced appears yellowish white and is also called warm light.

In the middle is 3000K to 3500K, which is more of a harsh white color without yellow or blue tint, and is sometimes called neutral bright light.

The phototherapy lights for SAD are designed to minimize ultraviolet exposure, even thought they are at the blue end of the spectrum.

Color Temperature by Signify, which is the new company name of Philips Lighting.



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