Your life and eyes 5 min read

The myths and the truth behind blue light

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There have been many stories in the media over recent years surrounding blue light, and the impact it can have on your health. In this article, we take a look at what blue light is, the impact it can have and how to protect yourself.

There have been many stories in the media over recent years surrounding blue light, and the impact it can have on your health; in particular, your sleeping habits. Many people believe that blue light is emitted solely from digital screens, which prompts a cause for concern in an age where we rely heavily on digital devices. There have been multiple sources of advice that tell you to put down your phone or tablet a few hours before bed, which a lot of people may associate with the idea of reducing your exposure to blue light.

The truth is that blue light is a little more complex than this and it’s important to understand the many different aspects of blue light and the consequences they can have on your overall health. With that in mind, we take a look at what blue light is, the impact it can have and how to protect yourself.

Existing beliefs about blue light

Many people associate blue light exclusively with digital screens, and live in the knowledge that looking at them too near to bed time will mean they experience inadequate sleep. This has led to the previously mentioned common sleep advice to turn off any devices at least an hour before bed.

woman staring at her phone sitting behind a laptop

A lot of people may also believe that this is a new phenomenon, because of our lifestyles and how often we now use digital devices compared to previous generations.

These thoughts are possibly the most widespread beliefs when discussing blue light, but there is more to it than that. 

What is blue light?

Blue light refers to just one part of the spectrum of light emitted, but it can’t really be seen as its own entity. Blue light is everywhere; but particularly found in sunlight and to a lesser extent in LEDs. In other words, the phenomenon of blue light is nothing new. Our lifestyles have changed in more ways than one, with greater exposure to sun and increasing use of LED lighting than our ancestors. For this reason, we are at greater risk of health issues relating to harmful blue light.

However, it’s important to understand that blue light is an umbrella term, referring to different variations. It is blue-violet light that is the harmful light, because it is a contributing factor of AMD (age-related macular degeneration) and blindness through damage to the retina. 

There is also something known as blue-turquoise light, which isn’t harmful and is actually necessary for our cognitive and sleep behaviour. There is a very thin line between the two, which can create confusion when trying to determine the risks and consequences of being exposed to blue light. 

Blue light blocking glasses light spectrum explained

The wavelengths of blue-violet and blue-turquoise light are very close together, which can make it difficult to avoid the harmful light while still being exposed to the beneficial blue-turquoise light.

The connection between blue light and digital screens 

Our ancestors would go to bed when the sun went down, and get up when the sun rose again. Now, we extend our days with the likes of artificial lighting and continue to stimulate ourselves, often through the use of digital screens, late into the night. Our ancestors didn’t have access to televisions, or LED lighting, and as such were not at greater risk of blue light as much as we are now.

There is some truth to the emitting of blue light from screens, but it is very dependent on the type of technology used. It has been stated that blue light represents around 24-30% of daylight, with the luminance of a sunny sky reaching at least 5000 cd/m2 (the unit of luminance). In comparison, a computer screen reaches around 250-300 cd/m2.

How to protect your eyes from blue light

As our lifestyles continue to change and evolve, it’s important to source the right technology that adapts with us. At Essilor, we have created Eye Protect System. The first of its kind, Eye Protect System offers front and back lens protection against harmful light, by partially filtering blue-violet light and absorbing UV light, which is also dangerous for our eyes.

Eye Protect System is an embedded innovation within the lens itself, providing protection while delivering an aesthetically clear lens. Tackling the thin line between beneficial and harmful blue light, Eye Protect System will allow blue-turquoise light through. 

So, if you’re concerned about the impact of blue light when it comes to your eye health, talk to your local optician about Essilor lenses with embedded Eye Protect System innovation.