Can you play with your phone safely by turning on the “eye protection mode”?

now

Whether it is work or life

All kinds of electronic devices are indispensable

Staring at the screen for long periods of time

Our eyes have

'Overwhelmed'

In order to protect their eyes, many people will turn on the "eye protection mode" to make the colors of mobile phone and computer screens softer, but is this really useful? Can the eye protection mode of mobile phone and computer screens really effectively protect our eyes?

Today we will study:

What is the principle of eye protection mode?

Can turning on the eye protection mode really protect your eyes?

How to effectively protect our eyes?

How does eye protection mode work?

“Eye protection mode” actually allows the display to automatically filter out some of the blue light , making the entire screen soft and not dazzling.

The natural light we often talk about, that is, sunlight, is composed of seven different colors of light: red, orange, yellow, green, blue, indigo, and violet. Among them, "blue" is what we call blue light, and its wavelength range is between 380nm and 500nm. The effects of blue light on the eyes have both advantages and disadvantages:

Long-wave blue light with a wavelength range of 440nm-500nm is beneficial . It can reach the optic nerve through the retina and be transmitted to the hypothalamus to synthesize melatonin and serotonin, which can help sleep, improve mood, and enhance memory.

Short-wave blue light with a wavelength range of 380nm-440nm is harmful . It can reduce sleep quality and even cause photodamage to the retina.

The white light emitted by general electronic screens is composed of red, green and blue light. The eye protection mode uses software algorithms to highlight the red and green light in the RGB tone and reduce the blue light .

However, it should be noted that the blue light will be reduced after the eye protection mode is turned on, but this does not mean that the blue light will disappear . In other words, electronic products in the eye protection mode only "shield" part of the blue light. Using this method of adjusting visual light to protect the eyes can only play a very weak role to a certain extent.

In addition, excessively reducing blue light will make red and green light higher than blue light, which will cause the screen to turn yellow or even distort. If the screen is too dark, it will also affect the eyes.

For example, the pupil can control the amount of light entering the eye, and it can adjust its size according to the intensity of the light. When the light outside becomes stronger, in order to prevent too much light from entering the eye and causing damage, our pupil will become smaller; when the light outside is weak, in order to allow more light to enter the eye and allow us to see clearly, the pupil will become larger.

Therefore, when the eye protection mode is turned on, the screen is too dark, and the pupil will become larger in order to increase the amount of light entering the eye. If the pupil is in a tense and enlarged state for a long time, the eyes will become tense, tired and sleepy, and it will be more laborious to use the eyes. In the long run, it may also deepen the degree of myopia .

The eye protection mode is only to reduce the impact of blue light on the retina, but playing electronic products for a long time will still cause great harm to the eyes. Therefore, even if the warm color system does look more comfortable than the cool color system, you can't stare at the phone for a long time in the eye protection mode .

Misconceptions about eye care

In addition to turning on the eye protection mode, some friends will "protect their eyes" by changing green wallpapers, lowering the brightness of the mobile phone screen, wearing anti-blue light glasses, etc. So, are these methods useful?

1. Turn your phone screen green

In fact, there is no scientific basis for "green eye protection" . When we look at flowers, plants and trees in the distance, our eyes feel comfortable. This is mainly because the ciliary muscles continue to contract when we stare at something close for a long time. Looking into the distance can relieve their tension. It has nothing to do with the color or object we are looking at.

Just looking at green does not relax the ciliary muscles, so they will still get tired when they should, and they will still get nearsighted when they should. In addition, the use of a green screen saver may also cause eye discomfort due to excessive color deviation .

2. Turn on night mode

We have explained in the article "Daily Science Popularization | Will lowering the brightness of the phone hurt your eyes?" that a screen that is too yellow or too dark will cause serious color distortion and accelerate eye fatigue. Ensuring that the picture on the screen is bright and clear is the right way to protect your eyes .

3. Anti-blue light glasses

Anti-blue light glasses reflect short-wave blue light through a layer of coating on the surface of the lens; or add anti-blue light factors to the base material of the lens to absorb blue light.

As we said before, not all blue light is harmful. Some bands of blue light are beneficial and necessary for the human body , and play a role in regulating the body's biological clock and stabilizing emotions. For example, blue light in the 460 to 490 nanometer band can effectively inhibit the secretion of melatonin. If it is blocked, the normal physiological rhythms of the human body, such as blood pressure and heart rate, may be affected.

Therefore, the Technical Requirements for the Application of Blue Light Protection Film for Light Health and Light Safety stipulates that the light transmittance of long-wave blue light must be greater than 80% , which means that blue light blocking glasses cannot block long-wave blue light. However, the quality of blue light blocking glasses on the market varies greatly. Some unqualified blue light blocking glasses can block short-wave blue light, but also block long-wave blue light.

Therefore, when choosing anti-blue light glasses, you must pay attention to its light transmittance for long-wave blue light .

How to protect your eyes properly

1. Implement the "20-20-20" eye protection principle

The "20-20-20 eye protection principle" means that every 20 minutes of computer use, look at something 20 feet (about 6 meters) away for at least 20 seconds. If you are too busy at work and cannot take frequent breaks, it is recommended to take a 5-minute break after 45 minutes of continuous eye use .

2. Blink more

The main factor of eye fatigue is the continuous tension of the ciliary muscles of the eyes. Blinking more often can relax the ciliary muscles and relieve eye fatigue caused by staring at the screen.

In addition, blinking allows the eyes to evenly spread tears on the cornea to moisturize the cornea . If you do not blink for a long time, the evaporation of tears on the surface of the cornea will cause dry eyes. In severe cases, it can cause eye diseases such as dry eyes.

When working in front of a computer for a long time, people will unconsciously reduce the number and frequency of blinking. To this end, we can consciously blink every 10 to 15 seconds to effectively protect our eyes.

3. Use the correct posture

I believe that many of our friends were asked by their teachers to sit at the table and read or write "one foot, one inch, and one fist" when they were young, because maintaining such a sitting posture can effectively protect the eyes, and the posture when looking at electronic screens should also be correct.

When working, you should keep the computer screen at an arm's length away from your eyes, and the screen height should be slightly lower than your line of sight. When playing with your mobile phone, you should try to keep the distance between your eyes and the phone at about 30 cm .