What hinders your sleeping may be a smartphone that gets poppy pounding before going to bed
I think that some people have experienced that they have not experienced a difficulty falling asleep if they are playing smartphones, but this is said to be the result of the blue light emitted by smartphone displays. A research result announcing that such a blue light is being emitted more and more of the latest digital device is released.
Phones need 'bed mode' to protect sleep - BBC News
For digital terminals used indoors and outdoors, such as smartphones and tablets, "brightness" and "contrast" of displays are particularly important. Increasing 'brightness' and 'contrast' makes it easier to see the display even under the sun, but in recent years more terminals equipped with "brighter and higher contrast" display are increasing, this is called "human It is a cause of hindrance to sleep, "research results have been announced.
Dr. Paul Gringrass, a doctor at Everina-London Children's Hospital and St. Thomas Hospital and a lecturer at King's College London, said that "smartphones, tablets, e-book readers, etc." Research on the resultsPublished at Frontiers in Public HealthDid.
In research, we used three of iPhone 5s, iPad Air, and Kindle Paperwhite (1st generation) as representatives of smart phones, tablets and e-book readers, and in what kind of situation they emit light of what kind It is measuring whether it is.
The following figure summarizes the measurement results. As a result of measuring the type of light emitted by displaying text on three terminals, although there is a difference in the intensity of light emitted from each terminal, every terminal strongly emits "blue light" It was revealed.
When the human body is at night, sleep hormone "Melatonin"Is produced. It is a substance that is deeply involved in sleeping, and it is said that melatonin influences coming back at night. Blue light has a function to interfere with "sleeping system of human body" by such melatonin. Blue light is the light with the strongest energy among visible light, it is said to be included in many LED displays such as PC and smartphone.
In fact, Dr. Gringrass says that the latest digital handset is "bigger, brighter, with higher contrast, more blue lights are starting to emerge," manufacturers are interfering with people's sleep We assert that we should have "responsibility" for digital terminals. Specifically, Dr. Gringrass says "We should be able to remove blue lights in setting." According to a certain research result, there is data that when you use a digital terminal at night, sleeping is delayed by 1 hour.
However, even when using the same device, we know that "which light is strongly emitted" depends on the application being used. The graph below measures the light emitted by the display when displaying text on iPad Air and playing Angry Birds. As you can see at a glance, depending on what you display, the type of light emitted from the display changes.
Also,Software that automatically cuts blue lightIt is also effective to use glasses for blue light cut and use it. Actually, some iOS applications cut the blue lightApps that induce children's sleepThere also exists, and the manufacturer should do the efforts for such a blue light cut, Dr. Gringrass. Specifically, "We insist that it is important to be able to cut blue light automatically."