Why is blue light bad?

Why is blue light bad?

Have you heard the statement “blue light is bad” and wondered how your digital screen could possibly affect your health? Even, why you should care?

Consider the effects of UV light. Premature aging, wrinkles, sun spots, eye damage, impaired vision and cancer are well known potential consequences. Yet, we didn’t understand this reality until science widened our field of view in the 1900s.

Light falls along a wavelength spectrum. The lower the nanometers (nm), the more energy is stored within. It is high energy that damages living cells and tissue. UV light is found between 100 and 400nm. Blue light, by contrast, sits between 400 and 500 nm. Less damaging than UV rays, but with considerable power none-the-less

Throughout history, blue light came and fell with the sun’s rays. Since the dawn of the digital age, however, exposure has exploded. Every day and night, televisions, computers, tablets, eReaders, smartphones, fluorescent and LED lighting harness blue light to provide illumination. Its ubiquity means we face a veritable onslaught. There is no longer an escape with the sunset. This fact detrimentally impacts on our health.

Yet as with all science related discoveries much time and investigation is required to reach solid conclusions. Then, once established, this information takes an extended period to disperse and become widespread knowledge. This is where we currently find ourselves: Blue light has been and continues to be well investigated, yet the study results aren’t well known. The facts remain dangerously hidden.

In this article, you’ll learn five ways that blue light can harm your health. Plus, an easy strategy to limit your exposure and protect your wellbeing.

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Why is blue light bad for your eyes?

Blue light exposure can lead to inflammation, dry eyes, cataracts and visual damage. Three particularly vulnerable parts of the eye include the cornea, lens and retina.

By increasing what’s called reactive oxygen species (ROS) in the cornea, these unstable molecules trigger inflammation. This can lead to cell death and propel a vicious cycle of further inflammation and dryness of the cornea and conjunctiva. If you experience scratchy, parched eyes this might be the cause.

As blue light hits the lens it is absorbed by proteins, enzymes and metabolites. This protects the retina from damage. Sadly, the protective mechanism works similar to drawing down a blind; a physical opaque barrier is created to block the light. It is these changes that contribute to cataract formation.

The retina is a special area at the back of the eyeball that is crucial for vision; no retinal function, no sight. As light hits the retina, electrical activity is sent to the brain and converted into images. But blue light diminishes this electrical output. It also increases ROS. This can harm your vision.

Research published in the International Journal of Ophthalmology noted that, “High energy short wave blue light between 415 and 455 nm is the most harmful.”

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Why is blue light bad for your sleep?

We, humans, are designed to follow the sun. As it rises and sets, so should we. This 24 hour (ish) cycle is called the circadian rhythm.

As the morning’s rays split the dark, light stirs awakening. Cortisol elevates, energy surges and the roused part of the cycle begins. Then, as evening approaches, cortisol quietens and our sleep hormone, melatonin, rises. At this time, melatonin readies the body and mind for slumber.

However, exposure to blue light throughout the day and night suppresses our melatonin level. This change can make it difficult to fall asleep and may contribute to insomnia.

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Why is blue light bad for your skin?

It can sound like a jump, can’t it? How can blue light emitted from your laptop possibly damage your skin?

Think back to UV rays and consider the sunburn they can cause. There is ample energy contained in the lower light wavelengths.

Studies show that exposure to blue light within the lower half of its wavelength range increases a process called intracellular oxidative stress. In essence, the inside of a cell becomes exposed to the reactive oxygen species we talked about earlier.

How can this effect our skin?

A study published in the journal BioMolecules put it succinctly, “Oxidative stress in skin plays a major role in the aging process.

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Why is blue light bad for the environment?

Blue light doesn’t remain confined neatly in a solitary device. You’ll notice this in a city. It’s always on, invariably at least partially lit, and the illumination drowns out the appearance of the night sky. The sheer volume contributes to what’s called light pollution.

While we tend to consider blue light in terms of our health, light pollution has far reaching consequences. Just as it affects human eyes, hormones, sleep and skin, these wavelengths affect other creatures and organisms. As a report by the Royal Society of New Zealand noted, “The effects of blue light in the environment on wildlife include similar disruption of biological clocks, and may affect plant growth, pollination, reproduction, migration, predation, and communication.”

The idea of blue light may sound innocuous. But remember: the higher the energy within a wavelength, the more power it has to damage living tissues. That’s why the authors of the study Research progress about the effect and prevention of blue light on eyes provide recommendations we agree with wholeheartedly. In conclusion:

We should minimise the use of electronic devices at night and avoid the effect of blue light on the secretion of melatonin at night… In addition, when we use blue light rich products at night, the approved anti-blue light glasses or screen cover may be a good choice to avoid blue light induced injury.


How we reviewed this article:

Ocushield has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations.

Our experts continually monitor the health and wellness space, and we update our articles when new information becomes available.

Current Version
April 07, 2021

1 comment

  • Beth

    I’m currently using Zagg’s Invisishield on my phone and my finger prints leave this oily residue that makes it hard to see. Like rainbow blotches I have to constantly wipe away. Will that happen with your product?

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