Long-Term Effects of Blue Light Exposure

Could we possibly go without our phones and laptops for a few days? Chances are that attempting to do so is easier said than done. An often-overlooked side-effect on the over-reliance on our devices is the blue light that emanates from their screens.

Avoiding our phones, tablets, and PCs is slowly becoming impossible. Both our work and social lives are entangled with our devices. From several hours at our work desks to a few more hours at night, in bed, on our phones. It is almost constant and continuous exposure to blue light.

As such, it is only natural to wonder: What exactly is this blue light? Is it harmful? Are there any long-term effects? We explore the answers to these questions to get the best understanding of the matter.

What is Blue Light?

Simply put, blue light is visible light. It is a colour in the visible light spectrum that our eyes can see. It has a short wavelength, meaning that it produces high energy levels.

Sources of Blue Light: Natural vs Artificial

Blue light has various sources. It is the reason why the sky and large water bodies appear blue. Blue light wavelengths are scattered (more than any other form of light) by gases and particles in the earth’s atmosphere because of their short and high energy nature.

The sun was once the only producer of blue light and remains the only natural source. 

The advent of technology brought about the artificial sources of blue light like TVs, phones, tablets, LEDs, and fluorescent lights. Blue light improves on the brightness and clarity of the screens used in these devices.

Effects of Blue Light: Long-Term

So, what are the effects of blue light? There are both positives and negatives.

The Positives

There is usefulness to blue light.

  1. The Circadian Rhythm: In its natural form/ occurrence, that is, from the sun, blue light helps regulate the circadian rhythm. A circadian rhythm is a natural, internal process that regulates the sleep-wake cycle and repeats roughly every 24 hours. It helps tell our bodies when to sleep and wake up. Exposure to blue light during the day helps keep that rhythm in balance
  2. Blue Light for Treatment: There are applications in which blue light exposure is used for health purposes. This is because blue light boosts mood, alertness, cognitive function, and memory. It is used in the treatment of Seasonal Affective Disorder (SAD). This is a condition (a type of depression) that relates to seasonal changes.

The Negatives

Even with a couple of useful applications, blue light is still a cause for concern when it comes to health. Our eyes are not built to filter out or protect against blue light.

  1. Disruption of the Circadian Rhythm: While natural blue light regulates our circadian rhythm, artificial blue light from our phones disrupts it. The blue light emanating from our phones and laptops messes with our sleep cycle. Using a phone at night makes it take longer to fall asleep because the circadian rhythm is being disrupted.
  2. Digital Eye Strain: Blue light tends to flicker because of its nature, and this flickering affects clarity and sharpness. There is a resulting strain and fatigue in our eyes. This is digital eye strain. In the long term, there is blurred vision, headaches, and irritated eyes. With young children getting exposed to these screens very early on in their lives, the onset of digital strain can come very early, with more permanent effects on the eyes.
  3. Increased Risk of Macular Degeneration: Macular degeneration, also known as age-related macular degeneration (AMD or ARMD), is a medical condition which may result in blurred or no vision in the centre of the visual field. Blue light penetrates the eye all the way to the retina, and over-exposure to blue light can damage the light-sensitive cells in the eye. Long exposure to blue light from digital screens can aggravate the onset of AMD.
  4. Increased Risk of Certain Types of Cancer and ‘Lifestyle Diseases’: Some studies link blue light exposure to certain types of cancer and diseases normally classified as ‘lifestyle diseases‘ like heart disease, obesity and diabetes. Exposure to a-light-at-night (ALAN) and disruption of the circadian rhythm correlates with an increased risk of hormone-dependent cancers. These long term effects do not have an exact root cause, but the fact that blue light suppresses the production of melatonin may shed light on the correlation.

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