Blue light and sleep
Sean Cain, a sleep researcher and associate professor of psychology at Monash University, says the increased exposure to Australian artificial blue light is a "health problem".
Exposure to blue light before going to bed may affect our ability to sleep in three ways: by suppressing our production of melatonin (which helps us sleep), increasing alertness and affecting the inner clock of our body (or circadian rhythm).
"Even though it may be 11 am, you will give your watch a signal that it is a day, that it is a few hours earlier, and then it's harder to sleep," explains Professor Cain.
There is also evidence that exposure to blue light can affect the sleep quality you have at night: the 2013 study by Swiss researchers showed that exposure to blue light even at relatively low levels (ie, sitting in a room illuminated with a standard LED lamp) you can reduce the amount of slow wave sleep (most restorative sleep type) person previously at night.
Because it's not just your phone that causes problems. Although people are exposed to less blue light every day than they would receive from the sun while living centuries of life habits, our exposure is now going through artificial sources in unnatural times, especially in the room when the sun descends.
"Most Australians have a very blue light in their surroundings, due to the decision to switch to more energy efficient LEDs," said Associate Professor Cain.
"It's okay to save money on energy, but it replaced the light that had less effect on our internal clock. Now we have these LEDs, which are very blue-enriched and we have them in our houses all the way to bed."
Can the blue light damage your eyes?
A brief answer to this question is: yes, but probably not the levels you are exposed to.
Much of the marketing around the lenses with a blue light is focused on the use of the screen during the day – Bailey Nelson's website claims that their filter "helps reduce the shape of the eyes and fatigue caused by screens and devices," while the "Oscar Vijle "blue lens is" for those who spend their days in front of a computer screen "- and how this can supposedly lead to eye strain.
However, Sophie Koch, Melmurn Optometry spokeswoman, says that more evidence is needed as to whether exposure to blue light specifically causes eye strain, which is an idea as a result of "limited, smaller studies and anecdotal evidence".
"The research is ongoing in this area and there are many other components that contribute to digital eyesight or" computer vision vision syndrome, "she says.
As far as serious eye problems are concerned, it is unlikely that these can be caused by your habit of a smartphone.
A New Zealand study by New Zealand, Te Apārangi, found that although retinal deterioration may occur after exposure to a strong light in high intensity, it will require a blue light level far greater than that which is appears with LED display.
With this evidence, Koch says: "At this stage … we do not have to worry about computers or phones that" sprinkle "our retina."
"Recent research has shown that even in extreme conditions, the level of blue light exposure from computer screens and mobile devices is smaller than that absorbed by natural daylight, which is below international limit values," she says.
Blue light glasses: are they worth the investment?
If you are concerned that sick eyes sit on a computer all day, Koh recommends that you seek optometrist advice to exclude common vision problems, such as uncoordinated refractive errors (which can be fixed with a prescription) or dry eye.
There are also other measures, such as as a rule 20-20-20 – every 20 minutes are viewed from your screen and at least 20 feet (six meters) in the distance in 20 seconds – or using an application such as F.lux or Apple Night Shift to filter the blue light on your smartphone, which can be useful.
But if you are mainly trying to improve the quality of your dream, the associate professor Cain says he will be "very supportive" to someone wearing a blue blue filter glasses in the evening, especially putting glasses at the same time each night to encourage the body to develop a regular circadian rhythm.
However, he will warn against wearing glasses with strong blue light filters throughout the day, as this could "potentially" affect vigilance.
"It has not been tested directly, but we know that blue light is warned throughout the day, so exposure to lots of blue light during the day could be quite good, not just for alerting, [also] giving your body a strong signal that it is a day, "he says.
"If you block that, you are in a situation where there is not enough signal for your watch to discover the difference between day and night. I think it would be a horrible idea to carry these things at any time of the day."
And if you want to buy blue light glasses so you can write in the early hours, keep dreaming: ultimately, there is no special pair of glasses that will overwhelm the putting on the phone before going to bed.
"It's obvious that if you use devices in a way that makes you more active – if you see job messages or worry about the next day – you will find it more difficult to fall asleep."
Mary Ward is the Sydney Morning Herald's Deputy Life-Style Editor and Time.