What is Blue Light? 3 Things You Need to Know

   
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November 26, 2018, by Bard Optical

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What time of day do you generally do the following things?

  • Watch TV to relax
  • Play video games
  • Check social media
  • Pay bills or shop online
  • Catch up on the news
  • Use your smartphone to text, read, or play games
  • Do homework at the computer

We’re guessing that you, like most people, generally do these things in the evening hours. And in fact, television networks define “prime time” as 7 to 10 p.m. in the Central time zone. The hours between the end of dinner and the time you turn in for the night are “prime relaxation time” for most Americans.

Besides the time of day, something else that activities on this list have in common is that they all involve electronic screens.

We know too much screen time is bad for us because it keeps us from being physically active, from being outdoors, from making meaningful social connections.

There’s one more reason to add to the list—blue light exposure.

 

What Blue Light Is

As Harvard University’s School of Public Health notes, “blue light has a dark side” because maintaining a healthy sleep cycle is more difficult to maintain with more blue light exposure. Computer and TV screens, as well as tablets and smartphones, all emit higher amounts of light from the blue part of the spectrum than sunlight or old-fashioned incandescent bulbs do.

So the hours we use to unwind with electronic screens are precisely the same hours of the day science tells us we should avoid blue light from those screens.

 

How Blue Light Affects Sleep

The Harvard study points out that “while light of any kind can suppress the secretion of melatonin, blue light at night does so more powerfully.” Melatonin is a chemical that our own bodies produce, and its release initiates the sleep cycle that is part of the daily circadian rhythm—the internal clock that regulates the sleep/wake cycle, the release of hormones, the digestive process, levels of alertness, and even body temperature.

The part of the brain in charge of circadian rhythm is the SNC, or suprachiasmatic nucleus. What input from our surroundings does the SNC use to keep time? Light signals coming from the eyes. The SNC translates the absence of strong light signals into messages telling the body to secrete melatonin. If your eyes are taking in lots of blue light, then your body won’t secrete melatonin.

Naturally, avoiding blue light from electronic screens all evening is the way to a healthier sleep cycle. That’s not a very feasible solution, however, for most of us. You can change your schedule only so much when you’re working, raising a family, or going to school.

Who is going to give up the only down time in their day and avoid television, tablets, computers, and phones entirely in their evening routine?

This is where optical innovation enters the picture. Opticians have devised a solution to this problem that will let you keep your evening Netflix binge session AND a good night’s rest. There are now special lenses that can specifically filter out wavelengths of blue light. They have an amber tint that block the wavelength of color opposite on the color wheel—blue.

 

What To Know About Amber Lenses 

  1. There is some indication that wearing amber lenses might be particularly helpful to those who struggle with low mood, such as those with depression and insomnia. A study in Chronobiology found that “mood also improved significantly relative to controls” in a group wearing blue-blocking amber lenses for three hours before bed.” A protocol that is non-invasive and involves no prescription drugs would be a welcome first line of defense for many patients with persistent mood imbalances. 
  1. All shift workers should consider using amber lenses, whether or not they need prescriptions for corrective eyewear. If you don’t normally wear glasses or contacts, a simple pair of amber tinted glasses is all you need. There are inexpensive options, as well as high-end couture frames and everything in between. Working the night shift or swing shift on a long-term basis is associated with many negative health outcomes, such as diabetes, obesity, heart disease, and even cancer. There is increasing evidence that it may be possible to reduce these negative effects through managing the amount of incoming light that throws off circadian rhythm. Blocking blue wavelengths during night work minimizes sleep disturbances.
  1. Digital eye strain is not something that can be addressed with amber lenses. While long periods of screen time cause both circadian rhythm disruption as well as digital eye strain, it is for different reasons. Digital eye strain has nothing to do with blue light exposure. Dry, red, achy, or irritated eyes are a result of staring at a computer or other electronic screen at close range for long stretches of time without interruption. It’s preventable by following the 20-20-20 rule: every 20 minutes, look away for 20 seconds at an object 20 feet away or more.

Amber lenses are a great investment in a healthy lifestyle for a many reasons and for many groups of people. Whether you work the third shift or you just want to be able to enjoy your screen time before bed, amber lenses are a sensible solution.

Bard Optical can match you with blue-blocking amber lenses in a style that fits your needs and your budget, and that’s fitted with your unique prescription. Forget rose-tinted glasses; amber-tinted glasses are the way to go for a healthy, balanced sleep cycle.

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