GUEST BLOG: Sleep & Blue Light

“Although there is some suggestion that blue light doesn’t impact sleep onset, we are all different in how we are affected by light exposure, and this is especially relevant to young people diagnosed with ASD or ADHD.” – Jan Jenner, Hunrosa sleep consultant

We all know how vital a good night's sleep is, yet many of us either struggle to prioritise it or fail to recognise the factors that impact its quality, potentially harming our health and wellbeing.

This World Wellbeing Week, we asked sleep consultant Jan Jenner from Hunrosa Sleep Consultancy about the impact of artificial light from technology use on our sleep quality. Here is what she had to say…


Natural daylight is important for our health and wellbeing, yet in recent times we have been increasingly exposed to artificial light, especially with the widespread use of digital devices at close range (including smartphones and tablets). As technology is advancing, it is important to understand how these devices can affect our health and how they can disrupt our sleep.

There has been evidence that light from screens, specifically blue light, impacts our circadian rhythm. This is the 24-hour clock that runs in cycles throughout the day to support essential functions and processes in the body, also referred to as our ‘body clock’. A consistent routine and regular bedtime and wake times will help to support this system, but one of the main influences on the body clock is light exposure. If we hold a device close to the face, light from the screen will be physically disruptive to the body clock and impact the natural onset of sleep. This is because artificial light suppresses melatonin, the hormone that helps us to fall asleep. Avoiding screen use at least an hour before bedtime, with a calming bedtime routine has been suggested as a way of reducing the impact of blue light on melatonin production.

However, in 2014 a study published by Gradisar et al, claimed that blue light before bedtime does not delay falling asleep by a significant amount of time. The blue light needed to delay the body clock has to be very bright, and our electronic devices don’t reach this level of brightness.

There are so many other factors to consider when thinking about what is affecting your sleep, such as your activity or exercise throughout the day, when you have eaten meals, caffeine intake, environmental lighting, temperature or noise. It is important to remember that as individuals we react differently to the exposure of this light and there may be other reasons why we could be struggling to sleep.

It is possible that the nature of content is disrupting our ability to fall asleep at a reasonable time. A topic we are exposed to can be physically alerting , such as a message on social media or a stimulating video. Gaming has been developed to create a ‘flow’ so that we are addicted and unable to end playing at a set bedtime. A recent study published by Pillion et al (2022) found that gaming and YouTube were associated with increased odds of insufficient sleep.

It remains to be to be seen how blue light from digital devices used at night before sleep time affects the sleep-wake cycle as research is evolving. Although there is some suggestion that blue light doesn’t impact sleep onset, we are all different in how we are affected by light exposure, and this is especially relevant to young people diagnosed with ASD or ADHD. Therefore, it is advantageous to adopt habits and routines to reduce any possible negative impact of using devices at night:


  • Regularity is important. Have a set bedtime and wake time in the morning to strengthen the body clock.
  • It is suggested that daylight exposure through the day can positively affect the negative impact of light exposure in the evening. Get outside during the day if possible, especially in the morning.
  • Avoid blue, green and bright white light from screens, projector lights and night lights. Use warmer tones and turn on night mode. Apply filters on devices, such as airplane mode which will stave off the need to check messages.
  • Consider how the content is likely to alert a young person. Also, if they want to connect with ‘friends’ when they should be sleeping.
  • Online gaming can be addictive and is difficult to finish once in ‘flow’. Have a definite ending to the time spent gaming by setting alarms and reminders to finish. Some young people may want to immerse themselves in a game to relax. Encourage this earlier in the evening then put devices away if possible. There may be other solutions to help them relax as a replacement such as an audiobook or podcast, sleep meditation, bath, yoga, massage..
  • The Sleep Wise app provides tailored advice and can be used to create sleep plans for multiple young people. Reliable up-to-minute advice "it was helpful to see it all there and just be able to flip through the different suggestions and ideas rather than going on to this website on, say, Google and then not knowing if that's a good source or whether that's someone's opinion(quote from app user)

In response to concerns shared by our special school members over learners' quality and quantity of sleep, NASS has worked in partnership with Hunrosa, leading UK sleep experts, to develop two innovative apps to help manage and improve sleep – Sleeptasia and Sleep Wise.

Discover more about these innovative tools and how they can promote healthier sleep habits by visiting our website -