It’s one of the most pervasive messages about technology and sleep. We’re told bright, blue light from screens prevents us falling asleep easily. We’re told to avoid scrolling on our phones before bedtime or while in bed. We’re sold glasses to help filter out blue light. We put our phones on “night mode” to minimise exposure to blue light.

But what does the science actually tell us about the impact of bright, blue light and sleep? When our group of sleep experts from Sweden, Australia and Israel compared scientific studies that directly tested this, we found the overall impact was close to meaningless. Sleep was disrupted, on average, by less than three minutes.

We showed the message that blue light from screens stops you from falling asleep is essentially a myth, albeit a very convincing one.

Instead, we found a more nuanced picture about technology and sleep.

What we did

We gathered evidence from 73 independent studies with a total of 113,370 participants of all ages examining various factors that connect technology use and sleep.

We did indeed find a link between technology use and sleep, but not necessarily what you’d think.

We found that sometimes technology use can lead to poor sleep and sometimes poor sleep can lead to more technology use. In other words, the relationship between technology and sleep is complex and can go both ways.

How is technology supposed to harm sleep?

Technology is proposed to harm our sleep in a number of ways. But here’s what we found when we looked at the evidence:

• bright screen light – across 11 experimental studies, people who used a bright screen emitting blue light before bedtime fell asleep an average of only 2.7 minutes later. In some studies, people slept better after using a bright screen. When we were invited to write about this evidence further, we showed there is still no meaningful impact of bright screen light on other sleep characteristics including the total amount or quality of sleep
• arousal is a measure of whether people become more alert depending on what they’re doing on their device. Across seven studies, people who engaged in more alerting or “exciting” content (for example, video games) lost an average of only about 3.5 minutes of sleep compared to those who engaged in something less exciting (for example, TV). This tells us the content of technology alone doesn’t affect sleep as much as we think
• we found sleep disruption at night (for example, being awoken by text messages) and sleep displacement (using technology past the time that we could be sleeping) can lead to sleep loss. So while technology use was linked to less sleep in these instances, this was unrelated to being exposed to bright, blue light from screens before bedtime.

Which factors encourage more technology use?

Research we reviewed suggests people tend to use more technology at bedtime for two main reasons:

• to “fill the time” when they’re not yet sleepy. This is common for teenagers, who have a biological shift in their sleep patterns that leads to later sleep times, independent of technology use.
• to calm down negative emotions and thoughts at bedtime, for apparent stress reduction and to provide comfort.

There are also a few things that might make people more vulnerable to using technology late into the night and losing sleep.

We found people who are risk-takers or who lose track of time easily may turn off devices later and sacrifice sleep. Fear of missing out and social pressures can also encourage young people in particular to stay up later on technology.

What helps us use technology sensibly?

Last of all, we looked at protective factors, ones that can help people use technology more sensibly before bed.

The two main things we found that helped were self-control, which helps resist the short-term rewards of clicking and scrolling, and having a parent or loved one to help set bedtimes.

Why do we blame blue light?

The blue light theory involves melatonin, a hormone that regulates sleep. During the day, we are exposed to bright, natural light that contains a high amount of blue light. This bright, blue light activates certain cells at the back of our eyes, which send signals to our brain that it’s time to be alert. But as light decreases at night, our brain starts to produce melatonin, making us feel sleepy.

It’s logical to think that artificial light from devices could interfere with the production of melatonin and so affect our sleep. But studies show it would require light levels of about 1,000-2,000 lux (a measure of the intensity of light) to have a significant impact.

Device screens emit only about 80-100 lux. At the other end of the scale, natural sunlight on a sunny day provides about 100,000 lux.

What’s the take-home message?

We know that bright light does affect sleep and alertness. However our research indicates the light from devices such as smartphones and laptops is nowhere near bright or blue enough to disrupt sleep.

There are many factors that can affect sleep, and bright, blue screen light likely isn’t one of them.

The take-home message is to understand your own sleep needs and how technology affects you. Maybe reading an e-book or scrolling on socials is fine for you, or maybe you’re too often putting the phone down way too late. Listen to your body and when you feel sleepy, turn off your device.

Chelsea Reynolds, Casual Academic/Clinical Educator and Clinical Psychologist, College of Education, Psychology and Social Work, Flinders University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Our ageing population brings a growing crisis: people over 65 are at greater risk of dual sensory impairment (also known as “deafblindness” or combined vision and hearing loss).

Some 66% of people over 60 have hearing loss and 33% of older Australians have low vision. Estimates suggest more than a quarter of Australians over 80 are living with dual sensory impairment.

Combined vision and hearing loss describes any degree of sight and hearing loss, so neither sense can compensate for the other. Dual sensory impairment can occur at any point in life but is increasingly common as people get older.

The experience can make older people feel isolated and unable to participate in important conversations, including about their health.

Causes and conditions

Conditions related to hearing and vision impairment often increase as we age – but many of these changes are subtle.

Hearing loss can start as early as our 50s and often accompany other age-related visual changes, such as age-related macular degeneration.

Other age-related conditions are frequently prioritised by patients, doctors or carers, such as diabetes or heart disease. Vision and hearing changes can be easy to overlook or accept as a normal aspect of ageing. As an older person we interviewed for our research told us

I don’t see too good or hear too well. It’s just part of old age.

An invisible disability

Dual sensory impairment has a significant and negative impact in all aspects of a person’s life. It reduces access to information, mobility and orientation, impacts social activities and communication, making it difficult for older adults to manage.

It is underdiagnosed, underrecognised and sometimes misattributed (for example, to cognitive impairment or decline). However, there is also growing evidence of links between dementia and dual sensory loss. If left untreated or without appropriate support, dual sensory impairment diminishes the capacity of older people to live independently, feel happy and be safe.

A dearth of specific resources to educate and support older Australians with their dual sensory impairment means when older people do raise the issue, their GP or health professional may not understand its significance or where to refer them. One older person told us:

There’s another thing too about the GP, the sort of mentality ‘well what do you expect? You’re 95.’ Hearing and vision loss in old age is not seen as a disability, it’s seen as something else.

Isolated yet more dependent on others

Global trends show a worrying conundrum. Older people with dual sensory impairment become more socially isolated, which impacts their mental health and wellbeing. At the same time they can become increasingly dependent on other people to help them navigate and manage day-to-day activities with limited sight and hearing.

One aspect of this is how effectively they can comprehend and communicate in a health-care setting. Recent research shows doctors and nurses in hospitals aren’t making themselves understood to most of their patients with dual sensory impairment. Good communication in the health context is about more than just “knowing what is going on”, researchers note. It facilitates:

• shorter hospital stays
• fewer re-admissions
• reduced emergency room visits
• better treatment adherence and medical follow up
• less unnecessary diagnostic testing
• improved health-care outcomes.

‘Too hard’

Globally, there is a better understanding of how important it is to maintain active social lives as people age. But this is difficult for older adults with dual sensory loss. One person told us

I don’t particularly want to mix with people. Too hard, because they can’t understand. I can no longer now walk into that room, see nothing, find my seat and not recognise [or hear] people.

Again, these experiences increase reliance on family. But caring in this context is tough and largely hidden. Family members describe being the “eyes and ears” for their loved one. It’s a 24/7 role which can bring frustration, social isolation and depression for carers too. One spouse told us:

He doesn’t talk anymore much, because he doesn’t know whether [people are] talking to him, unless they use his name, he’s unaware they’re speaking to him, so he might ignore people and so on. And in the end, I noticed people weren’t even bothering him to talk, so now I refuse to go. Because I don’t think it’s fair.

So, what can we do?

Dual sensory impairment is a growing problem with potentially devastating impacts.

It should be considered a unique and distinct disability in all relevant protections and policies. This includes the right to dedicated diagnosis and support, accessibility provisions and specialised skill development for health and social professionals and carers.

We need to develop resources to help people with dual sensory impairment and their families and carers understand the condition, what it means and how everyone can be supported. This could include communication adaptation, such as social haptics (communicating using touch) and specialised support for older adults to navigate health care.

Increasing awareness and understanding of dual sensory impairment will also help those impacted with everyday engagement with the world around them – rather than the isolation many feel now.

Moira Dunsmore, Senior Lecturer, Sydney Nursing School, Faculty of Medicine and Health, University of Sydney, University of Sydney; Annmaree Watharow, Lived Experience Research Fellow, Centre for Disability Research and Policy, University of Sydney, and Emily Kecman, Postdoctoral research fellow, Department of Linguistics, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.