Recent Studies Link Blue Light Emission to Poor Sleep, Depression and Cancer

The Darker Side Of Blue Lights And What You Can Do About It

The short-wavelength blue light, emitted by the screens on our tech gadgets, damages quality of our sleep, concludes a recent study published by the University of Haifa and Assuta Sleep Clinic. Another study published by Harvard Health Publishing links working the night shift and exposure to light at night to several types of cancer (breast, prostate), diabetes, heart disease, and obesity.

On the other hand, the study also identified that red light emitted by electronic displays does not affect the quality and length of sleep patterns, and is comparable to normal sleep. 

As much as we enjoy basking in the blue light of our tablets or smartphones and reading in bed, we may need to make some changes.  Blue light throws the body’s biological clock—the circadian rhythm—out of its natural rhythm.


“The light emitted by most screens — computers, smartphones, and tablets — is the blue light that damages the body’s cycles and our sleep,” explains Prof. Abraham Haim from the University of Haifa, one of the authors of the study. “The solution must be the use of the existing filters that prevent the emission of this light.”

Multiple studies have linked working the night shift and exposure to night light to several types of cancer (breast, prostate), diabetes, heart disease, and obesity. One of the risk factors is that exposure to light suppresses the secretion of melatonin, a hormone that influences circadian rhythms, and preliminary experimental evidence suggests that lower melatonin levels might explain the association with cancer.

But not all colors of light are bad and exposure during various time of the day plays a role. Blue wavelengths are beneficial during daylight hours because they boost attention, reaction times, and mood, but they seem to be the most disruptive at night. Harvard researchers and their colleagues experimented comparing the effects of 6.5 hours of exposure to blue light to exposure to green light of comparable brightness. The blue light suppresses melatonin for about twice as long as the green light and shifted circadian rhythms by twice as much (3 hours vs. 1.5 hours).

Various companies are tackling this problem and offering commercial solutions such as blue light blocking eyewear, and blue light filters for your smartphone and electronic gadgets.

Diagram courtesy of Prospek inc.

Blue-Blocking Glasses

The University of Toronto conducted a blue light study that involved comparing the melatonin levels of people exposed to bright indoor light who were wearing blue-light–blocking goggles to people exposed to regular dim light without wearing goggles. The people wearing the glasses and those who weren’t showed the same levels of the melatonin hormone, indicating that goggles do work and make a good case for wearing eyewear that blocks blue light.

Inexpensive sunglasses with orange-tinted lenses block blue light, but they also prevent other colors, so they’re not suitable for use indoors at night. Glasses such as Prospek that block out only blue light can cost up to $80, a low price to pay for good health.

Prospek Artist – 50% Blue Light Blocking $39.95 USD


The Prospek’s collection starts at $33.95 up to $55.95 and represents Spektrum’s blue light blocking glasses for different needs, gender and age groups, with a good selection even for kids. The Vancouver, British Columbia, eyewear company offers glasses with a 50% blue light blocking and 99% blue light blocking filters. The 50% come in a clear lens while the 99% have a darker yellow lens. The company recommends wearing their glasses for all your computer activities all day, not just at night. “Besides sleeplessness, blue light can affect your retina, strain your eyes, give you headaches and dry eyes,” said James Edwards, co-founder of Prospek to The Scope Weekly. “Our eye wearers reported sleeping better and a migraine-free day after wearing them for only one day.” 

Blue Lights Filtering Apps and Settings

For Android devices, you may install  Blue Light Filter such as Twilight – one of the most popular in Google Play store. While “Sleep Cycle” is also one amazing app for the iPhone, Terry Lambert, a former employee of Apple, notes on Quora,  several other apps in iOS 9 which can help in filtering blue light. Lambert recommends Sleep Cycle, Twilight, CF.lumen, Screen Filter, BlueLight Filter. For your iPad, you may change your settings to the Low light mode in iOS while on the iPhone, there is an inbuilt IOS blue light filter, “Invert Colors1”. This setting is available in the Accessibility settings. It changes the illumination from black letters on a light background to an inverse of that.

Since the likelihood that we stop working at night or reading in bed, the Harvard Medical School recommends that we make some slight changes to limit your exposure to nighttime blue lights:

  • Use dim red lights for night lights. Red light has the least power to shift circadian rhythm and suppress melatonin.
  • Avoid looking at bright screens beginning two to three hours before bed.
  • If you work a night shift or use a lot of electronic devices at night, consider wearing blue-blocking glasses or installing an app that filters the blue/green wavelength at night.
  • Expose yourself to lots of bright light during the day, which will boost your ability to sleep at night, as well as your mood and alertness during daylight.
  • Wear eyewear to block or filter blue lights and to prevent straining your eyes
  • Change your computer display setting
  • Install a blue light filtering app on our smartphone or tablet

With those preventive measures applied to your daily routine, you should rapidly see an improvement in the quality of your sleep and your overall health.

What kind of sleeping patterns do you have? Do you spend more than four hours a day in front of the computer? Do you read at night in your bed? Would you consider wearing blue light blocking glasses such as Prospek or change your device’s settings? The Scope Weekly likes to hear back from you.  Let us know if you try any of the suggestions above.

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Source: University of Haifa. “Blue light emitted by screens damages our sleep, study suggests.” ScienceDaily. ScienceDaily, 22 August 2017.

Harvard Health Publishing. “Exposure to blue light at night, emitted by electronics and energy-efficient light bulbs, can be harmful to your health.” Published: May 2012

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