Mobile phones can be said to be the external organs of modern people. Now reading this article, you have been playing with your phone for hours?
The first thing to do when you wake up in the morning is to pick up your phone to read the news, and the last thing before going to bed at night is to set an alarm for your phone. Looking at the screen day and night, you can say that you are the most industrious "employee" in your body.
Maybe you've also considered providing some compensation for it. For example, buy a pair of expensive anti-blue light glasses in the optical store, or buy a mobile phone film with anti-blue light written on a treasure.
As a person who doesn't play with mobile phones, these products are really attractive. But you still haven't placed an order because you can't be sure, are these devices that claim to be "anti-blue light" really useful?
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Blue light has an effect on the eyes,
But limited
We can often make harmful remarks about Blu-ray on the Internet, and the various electronic devices we use every day will more or less emit blue light, which can't help but be frightening.
But blue light is not as scary as rumors suggest.
It does hurt your eyes, but it can only cause damage to your retina if the blue light you receive reaches enough time and intensity.
In general, various home lighting light sources and display devices do not produce strong blue light hazards, and there is no need to take protective measures [1].
That's not to say you don't have to worry about blue light at all.
Research from the University of Tübingen in Germany shows that when you are in a normal indoor environment and receive blue light radiation for thirty minutes, it causes you to fall into deep sleep thirty minutes later [2].
Lying in bed late at night with a cell phone is a lot of people's daily /visual China
That is to say, when you hide in the bed at night to brush vibrato, or try to see the whereabouts of the enemy from the eightfold mirror, these behaviors will make you "sleepless at night".
Why does blue light keep us awake?
This is because blue light is able to inhibit the secretion of melatonin in our bodies. Melatonin is a hormone that is naturally secreted in our body, which helps us to enter a state of sleep and improve the quality of sleep. Melatonin is reduced, and naturally you can't sleep [3].
So, is there anything that keeps us from being disturbed by blue light?
Take a look at a few common anti-blue light products
At present, several major anti-blue light products are anti-blue light glasses, anti-blue light mobile phone membranes and anti-blue light displays.
Anti-blue light glasses
When you look closely at the blue-light-proof glasses, you will find that their lenses are yellow and look very different.
This is because these glasses have a special coating on the lenses to absorb or reflect blue light [3].
Anti-blue light glasses / visual China
So do anti-blue light glasses really work?
Unfortunately, not at all. There is currently no high-quality clinical trial evidence that blue-light-proof glasses can reduce eye fatigue and discomfort.
Women wearing blue light-blocking glasses / Visual China
Scholars at City University in the UNITED have done related research, they compared anti-blue light glasses with ordinary glasses. Results showed that anti-blue light glasses were not effective in relieving eye fatigue and improving sleep quality [4].
And anti-blue light glasses are not cheap, no degree of flat mirrors can sell for hundreds of yuan, not to mention some nearly a thousand pieces of lenses. Therefore, the anti-blue light high-tech in the mouth of the optical shop clerk may not be worth a premium of several hundred yuan.
Anti-blue light mobile phone film
Anti-blue light mobile phone film is very common. Even the five-piece six-pack mobile phone film found on a treasure has an anti-blue light function.
Only sell 5.6 yuan anti-blue light mobile phone film / Taobao screenshot
So how effective are they in practice?
A team from the University of California, Irvine conducted the experiment. They divided the experimental subjects into two groups: anti-blue light mobile phone film and no mobile phone film. It was tested at different distances, brightnesses, and when eye protection mode was turned on.
The experimental results show that the effect of the mobile phone protective film on the weakening effect of blue light is even inferior to the eye protection mode of the mobile phone. When the brightness of the mobile phone is the maximum, the effect of the protective film to reduce blue light is basically half that of the eye protection mode [5].
You know, the eye protection mode is to reduce the blue light emitted by the screen through the algorithm, which comes with the mobile phone, so why waste money to buy an anti-blue light mobile phone film?
At this time, someone must have asked, if I use both of them, is the effect super doubled? In fact, according to the above experiments, the effect of the two used together is still better than the use of eye protection mode alone. So let's honestly use the eye protection mode.
The night mode of the Apple phone is actually the eye protection mode, which reduces the blue light exposure you receive before going to bed / the screenshot of the phone
Anti-blue light mobile phone film also has certain disadvantages. Anti-blue light mobile phone film will have color, which will affect the display of the color of the picture.
If you are a person who has high requirements for the color of the picture, such as video post-production, painting design, or even just helping the photo retouching, this product is not suitable for you.
Anti-blue light display
When you buy a new computer screen for yourself, you will often see those product advertisements on the online shopping platform, one by one, which are written "filter blue light, as comfortable as long-term use" and "meet the German TÜV Rheinland certification, without enabling hardware to effectively filter blue light" and other promotional slogans.
Product introduction of anti-blue light display / JD screenshot
Don't you understand what it means?
The so-called anti-blue light display is to innovate the LED backlight technology to increase the wavelength of blue light and reduce the radiation of harmful blue light [6].
Does the anti-blue light display work?
This time is different, the General Administration of Quality Supervision, Inspection and Quarantine and researchers of Zhongxing Optoelectronics Technology have proved that the anti-blue light display is effective after the experiment.
They compared participants with eye fatigue when using low-blue or general displays.
Experiment participants were asked to find the one with the opening in a small ring full of screens. Immediately after finding it, take the next test for 50 minutes.
实验任务截图 / Yi Lin Chen,,Yun Hong Zhang,,Liu Jia,... & Pan Xu. (2017). P‐36: Evaluate Fatigue of Blue Light Influence Under General LCD, Nice blue LCD Displays. SID Symposium Digest of Technical Papers(1).
The experimental results showed that participants who used low-blue light displays completed tasks faster and experienced less fatigue and stress growth.
It can be seen that the low blue light display can indeed reduce the visual fatigue caused by blue light to a certain extent. It also allowed participants to focus more on their tasks over long periods of time and remain calm.
The participants themselves also felt that when using the low-blue light display, there were fewer headaches and eye fatigue, which brought them a more comfortable overall use experience [7].
So if you're on a budget, you might as well buy a monitor with anti-blue light.
protect the eyes,
It's not about the equipment
In this way, in addition to the anti-blue light display, the protection function of other products is questionable.
But you don't have to worry too much, because the amount of blue light emitted from our common electronic screens is not as large as the amount of blue light in nature.
The blue light radiation in nature is compared with the blue light radiation of daily necessities, and some people abroad have experimented. Experiments have shown that the amount of blue light emitted by devices such as mobile phones and computers is lower than that in nature [8].
So we really don't have to be too afraid of these electronic screens, and more importantly, we must develop good eye habits.
The use of any eye protection product is actually a symptom rather than a cure. The biggest problem of modern people is not that they do not know how to protect their eyes, but that they do not have the consciousness to protect their eyes at all.
When you were young, both adults and teachers reminded you to protect your eyesight, now why did you forget all about it?
Some people work for ten hours at a time, and they don't move in front of the computer, so how can your eyes be good.
We must remember to apply the "20-20-20" rule in our working lives. Look twenty seconds away 20 feet (six meters) every twenty minutes to relax your eyes [9].
Don't forget to relax your eyes when you work / Visual China
I also blink more often when I work, because staring at the screen for a long time can make our blinking rate decrease, resulting in dry eye syndrome [10].
If the eyes are dry, do not rub your eyes casually, as doing so will cause changes in intraocular pressure, which can damage corneal cells and, in severe cases, may cause keratitis. Rubbing the eyes may also affect corneal curvature, which can induce astigmatism [11].
Rubbing the eyes is also a bad habit for the eyes / visual Chinese
The placement of office computers can also affect our eye health. It is best to place the computer screen at a distance of 70 cm from yourself, and adjust the angle of the screen so that the eyes can look down slightly, which can reduce the fatigue of the eyes [12].
Don't always play with your phone in the bed when you go home, the brightness of our phones when we play in the dark is often very high, which makes our eyes feel uncomfortable and cause eye fatigue [13]. Therefore, it is better to turn on the light when playing with the mobile phone.
Developing good eye habits is the foundation of eye health.
Of course, the current workers work so hard, go home to play mobile phones, brush drama, is the best rest, who cares about this blue light?