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Red screen at night, sleeper's delight: Apps claim to improve rest by placing a crimson filter over your phone's blue light

Scientists claim blue light could cause interrupted sleep and harm eyes
Various apps can filter the light on your phone to make it appear red
This reduces eye strain and doesn't disrupt your internal body clock

By Ellie Zolfagharifard For Dailymail.com

Published: 18:14 EST, 6 October 2015 | Updated: 00:21 EST, 7 October 2015

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If your sleep patterns are erratic, then your mobile phone could be to blame.

Scientists say the blue light emitted by electronic devices, increasingly used by people lying in bed, could lead to interrupted sleep or even harm our eyes.

Now a raft of new apps designed to transform the blue light into red light could save your sight and help you get a good night's rest.

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Scientists say the blue light increasingly used by people lying in bed, could lead to interrupted sleep or even harm our eyes. Now a raft of new apps designed to transform the blue light into red light could save your sight and help you get a good night's rest. Pictured are screenshots from 'Bluelight Filter for Eye Care'

According to an in-depth report by Andy Betts at makeuseof.com most of the blue light filtering apps work in a similar way.

When the clock on your phone shows that the sun has set, the apps place a red overlay on the screen to transform its colour temperature.

'This gives everything a red hue, which takes a little getting used to,' the report says.

'But it also cancels out the negative effects of the blue light, and massively decreases glare.

'Even if you’re skeptical about it improving your sleep, you will immediately notice a reduction in eye strain when using your phone in a dimly lit room.'

An example of one of these apps is Twilight, which comes in both a free and pro version, 'The filter intensity is smoothly adjusted to the sun cycle based on your local sunset and sunrise times,' the apps creators write on the Google Play store

There are, however, some issues with these red overlay apps. For instance, the red reduces contrast causing black to to appear dark crimson.

In Android, the shading can cause certain buttons to become inaccessible.

An example of one of these apps is Twilight, which comes in both a free and pro version,

'The filter intensity is smoothly adjusted to the sun cycle based on your local sunset and sunrise times,' the apps creators write on the Google Play store.

'Bluelight filter for Eye Care' is another option, with the same tools as the Twilight app.

There are, however, some issues with these red overlay apps. For instance, the red reduces contrast causing black to to appear dark crimson. Pictured are screenshots from the Twilight app

Another app named, CF.lumen gives you a choice of several filter to counteract the blue light.

It first converts the displayed image to grayscale, and then display that image in levels of the selected colour.

'This preserves details that would otherwise be lost,' according to a description of the app.

Scientists at Penn State and Harvard universities in the US recently found that those who regularly use e-readers before bed do not sleep for as long.

They take nearly ten minutes longer to fall asleep after using their devices, compared with those reading a printed book, and their sleep is far worse.

COULD BLUE LIGHTS REPLACE A DAILY CUP OF COFFEE?

Smartphones used before bed can cause restless nights because their light causes melatonin suppression which disrupts the body clock

Blue light has been getting a bad reputation lately for its role in disrupting sleep.

Smartphones and other gadgets used before bed can cause restless nights because their light causes melatonin suppression – a chemical which controls the body clock.

But there are some positives, according to a recent study, that looks at how blue light can make the brain more alert if it is used at the right time.

Researchers at Mid Sweden University compared the effects of caffeine and blue light on the brain and found them both to have a positive effect.

Interestingly, people exposed to blue light performed better on tests of brain function that included a distraction. The same distraction, however, proved too much for caffeine users, who performed poorly.

‘Blue light and caffeine demonstrated distinct effects on aspects of psychomotor function,’ said the authors of the report. ‘It has the potential to positively influence a range of settings where cognitive function and alertness are important.’

The researchers found they have less rapid eye movement, a stage of sleep thought to be crucial because it is when people consolidate memories.

Neuroscientist Dr Anne-Marie Chang, whose research was published in the journal Proceedings of the National Academy of Sciences, said screens have an ‘extremely powerful effect’ on the body’s natural sleep pattern.

‘Our most surprising finding was that individuals using the e-reader would be more tired and take longer to become alert the next morning,’ she said.

Nearly all living things have a body clock that synchronises to the 24-hour pattern of the Earth’s rotation.

The circadian rhythm, which also determines if we are a ‘morning’ or an ‘evening’ person, is regulated by the senses, most importantly the way the eye perceives light and dark.

Blue light, which is emitted by the low-energy light-emitting diodes used in smartphones, tablet computers and laptops, is known to be particularly disruptive to sleep.

As well as apps, technology firms are developing ‘safe screens’ to address fears that smartphones and tablet computers may be keeping us awake at night.

The new ‘safe screens’ are said to work by emitting less light from the violet end of the blue spectrum, the most harmful part.

Paul Gray, an analyst at the business research firm IHS, said: ‘We’ve been told from a very early age by parents that too much screen time, in front of a TV or a computer, is bad. So a “safe” screen might resonate with consumers.’

But some researchers are sceptical about blue light fears.

Serge Picaud, at the Institute of Sight in Paris, said: ‘We should not be so afraid that we bin all our screens. The light intensities produced by our screens are still relatively weak compared to sunlight.’

And Vincent Gualino, a French ophthalmologist, said the real problem is not the devices but ‘over-consumption’, warning people against spending more than six hours in front of screens.

As well as apps, technology firms are developing ‘safe screens’ to address fears that smartphones and tablet computers may be keeping us awake at night because of the blue light which is emitted