Why is Everyone Talking About Blue Light?

My curiosity in artificial blue light and its potential effects became heightened as we entered online learning. The increased screen-time during this period obviously had several facets, whether it was to stay connected to friends and family or to continue learning, it has been a necessity. Whilst we were able to innovate our teaching styles and adapt to the situation, I did start to question the ‘bigger picture’. We have transitioned in our habitual natures to using technology for almost everything, but at what cost? Is it ok for everyone to now check their devices as they are about to fall asleep and again when they wake up? Whilst the learning journey has been turbulent at times, it has also been steep and rewarding. Our pupils’ computer literacy skills have improved immeasurably and our personal methods for storing and retrieving information have also evolved. Within my role at the College, I am as expected, always conscious of both my health and others around me. One area I have become especially interested in is eye strain due to increased screen-time. Furthermore, with this ‘new normal’ I have no doubt that we will permanently embrace some of these newfound ways to teach and work collaboratively in the workplace. So trying to understand any potential lasting effects both biologically and socially is proving to be increasingly important.

On a personal note, having seen my own children develop their knowledge through the use of technology, I know that there are huge benefits to the learner, but I do always question and probe –

What, if any, are the potential risks with this necessary approach to learning at the moment? 

Blue light is certainly a factor that needs considering. Blue light has been around for millions of years, in fact forever! It is part of the light spectrum that our pupils learn about in science here at MCM. The new phenomenon though is the creation of artificial blue light. Our basic understanding is that artificial blue light can be harmful and is found in energy-saving LED light bulbs, computers screens, tablets, flat-screen televisions and mobile devices. What people do not tend to understand is that natural blue light is essential for our well-being, especially from a regulatory standpoint.

The Science:

The Science:

Blue light is a necessary part of the light exposure that we need for healthy long term growth. The introduction of artificial blue light is still something that is not fully understood. What we do know from Spectral analysis is that the sun has all the colours of the spectrum, with a very even amount of colour being distributed and absorbed by our bodies. Although the sun can cause us to burn, it also helps our bodies regulate cortisol, serotonin and dopamine levels – three essential neurotransmitters that are needed in the day for wellness and being active. The other important piece of information to note is that there is an inverse relationship between the wavelength of light rays and the amount of energy they contain. Light rays that have relatively long wavelengths contain less energy, and those with short wavelengths have more energy. Rays on the red end of the visible light spectrum have longer wavelengths and, therefore, less energy. Rays on the blue end of the spectrum have shorter wavelengths and more energy.


In modern society, we are now being exposed to an uneven amount of light. Ancestrally, we were only exposed to red light after dark i.e fire for cooking. The blue lights emitted from our television screens, computers, phones and light bulbs are all starting to give us an uneven exposure of blue light. The full effects of this are still unknown but what we do know is that it is starting to have some effects on our sleeping patterns and our eyes.  


As we know from previous blogs, sleep is a vital part of our overall well-being and can have a huge impact on how we function throughout the day with respect to cognition but also social and emotional interactions. There are two main factors that send us to sleep. Firstly, ‘sleep pressure’ which occurs when we burn ATP (adenosine triphosphate) in the mitochondria (a byproduct of adenosine) that builds up in the brain where it applies so much pressure that we feel the need to sleep. The second factor is known as ‘the circadian way’, which is our body clock. Our environment creates light in the day that forms blue wavelengths i.e the sun or household lights. This in turn sends a message to our brains to let us know we should be awake.


The problems arise now that we are artificially creating light in our households, which is sending messages to our brain that in fact, it is not bedtime. At night we should be creating an environment that allows our bodies the time to reduce cortisol and increase melatonin (the chemical we release to make us sleepy).

Moving light v Flicking Light

Flicking light is very different from moving light. If you video your TV or computer screen in slow motion and watch it back you will see the image ‘flickers’. Whilst the ‘flickering fire’ would score you points with your English teacher, as a good use of alliteration, it is not strictly correct. The fire actually ‘moves’ – the light is constant. This may seem trivial but actually this plays a keen role in understanding why we potentially get headaches and digital eye strain. 

As previously stated, blue light is a shorter wavelength and it, therefore, scatters more easily – hence the reason why we see those vast big blue skies. Problem is that our eyes have to work so much harder to focus on this flickering blue light when we stare at our screens. So managing our exposure and preventing headaches and digital eye strain is now a real issue. The simple approach would be to boycott technology altogether but think of all the advances we have made and the endless opportunities that are yet to be realised. It is much more sensible and realistic to look at developing strategies that allow the use of technology whilst still supporting our long-term health.  Below are some basic guidelines that will help prevent any disruptions to your circadian rhythm (from a light perspective) and will hopefully minimise any eye strain.

The take-home guide to blue light 

  • Use dim red lights for night lights. Red light is less likely to shift circadian rhythm and suppress melatonin.
  • Take regular breaks from the screen – go for a walk or make a drink.
  • Avoid looking at bright screens two to three hours before bed – consider wearing blue-blocking glasses (get what you pay for) or installing an app that filters the blue light 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.
  • Shift your device to night mode where possible.

This blog is intended to educate and inform, if you have any concerns about eye strain, please contact your local GP. We are not able to offer any medical advice, only to merely explore ways in which we can better the educational experience for our pupils here at Marlborough College Malaysia, both online and in class. 

Jamie Lennard | Director of Sport and Head of Senior School Wellbeing

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