China News Service Client, Beijing, July 13 (Reporter Xie Yiguan) Because online teaching requires children to use mobile phones, computers and other electronic products for a long time, which places a greater burden on the children's vision, some businesses have begun to hype "blue light" of electronic products. "Hazard", publicize and sell anti-blue light glasses, anti-blue light film and other products that can "prevent myopia and protect eyesight".

  So, is blue light harmful to eyesight? Does "anti-blue light product" have the effect of preventing myopia? How to choose electronic products scientifically? What are the precautions when using electronic products? The Consumers Association of China recently sorted out the opinions of relevant experts and organized comparative test results. It was found that anti-blue light is not equal to anti-myopia. The prevention of myopia must first ensure eye hygiene.

Data map: Students at home online classes learn traffic safety knowledge online. Photo courtesy of Taigu traffic police

Blu-ray is not the "culprit" that causes myopia

  With the popularity of mobile phones, tablet computers and other electronic products and the increasing myopia rate of children and adolescents, coupled with the hype about the hazards of Blu-ray, many parents blame Blu-ray for the "criminal culprit" of myopia in children.

  But according to experts, blue light only has the possibility of causing damage to the retina, and this possibility is related to the dose of blue light received by the retina. In other words, blue light irradiation can only cause retinal damage after reaching a sufficient time and a certain intensity.

  Some experts pointed out that when the blue light band is below 445 nanometers, the light intensity exceeds a certain threshold and prolonged exposure is prone to photochemical damage to the retina, especially short-wave blue light near 435-440 nanometers is the most harmful. Some experts pointed out that the main damage to the eyes caused by blue light may be macular degeneration, but this is caused by long-term, high-intensity irradiation. Moreover, the medical community currently believes that the main factor affecting macular degeneration is age, not blue light.

  It is worth noting that blue light is also beneficial to the human body. Many experts believe that blue light between 480 and 500 nanometers has the effect of adjusting the biological rhythm, which can help promote sleep, stabilize emotions, and enhance memory. At present, there are studies on vision protection that show that blue light or violet light can even suppress myopia.

  China Consumers Association pointed out that the quality of electronic products has filtered harmful short-wave blue light, and its blue light hazard value is basically at a non-hazardous level. That is to say, the correct use of the blue light touched by mobile phones and tablets will not cause damage to the eyes. There is currently no direct evidence that blue light causes myopia. Therefore, parents need not worry too much about the so-called "blue light hazard".

Data map: Anti-blue light glasses.

Improper selection of anti-blue glasses is harmful to preventing myopia

  "Since blue light is not the cause of myopia, the so-called "anti-blue light products" obviously lack scientific basis to prevent myopia." The China Consumers Association said that for some businesses through false exaggeration of the performance of anti-blue light products, excessive interpretation of the hazards of blue light, Consumers should look rationally at the high price of anti-blue light products.

  Many experts pointed out that there is insufficient medical evidence to prove that products such as anti-blue glasses can play a significant role in preventing and controlling myopia. On the contrary, due to the large number of anti-blue light products and the uneven quality of the products, if they are not properly purchased, they can easily cause damage to the children's eyes.

  Some experts pointed out that the current anti-blue light glasses mostly have the following problems: first, some products have no protective effect on short-wave blue light that damages the eyes; second, some products are completely shielded from blue light, that is, excessive protection; third, because anti-blue light lenses are mostly If there is color, it will cause a certain "color cast". If it is used for a long time, it will easily aggravate the visual fatigue.

The eye protection mode effect of electronic products is better than anti-blue light film

  Among anti-blue light products, in addition to anti-blue light glasses, anti-blue light films are also quite popular among consumers.

  In order to understand the eye protection mode and anti-blue light film effect of mobile phone and tablet computer screens, the Consumer Council of Guangdong Province carried out a comparative test in 2019 for evaluation and comparison. The results show that the eye protection mode can play the role of reducing the blue light radiation ratio of the screen of the mobile phone and tablet computer, increasing the blue light peak ratio of the screen, reducing the screen brightness and reducing the color temperature of the screen, so that the total energy of the blue light band and the peak energy of the blue light band are suppressed.

  Although most of the films with the anti-blue light function can also play a role in reducing the blue light radiation ratio of mobile phones and tablet computers, increasing the blue light peak ratio of the screen and reducing the color temperature of the screen, the effect is not too obvious.

  In other words, the eye protection modes of mobile phones and tablet computers and some of the films that are nominally equipped with an anti-blue light function can play a role in anti-blue light. However, the eye protection mode that comes with electronic products is more comprehensive in terms of anti-blue light and more effective.

Data map: Primary and middle school students check their eyesight with their parents. Wei Liangshe

Different electronic products have different effects on children's vision

  What kind of electronic products are selected to help prevent myopia? China Consumers Association commissioned a professional testing agency in 2019 to conduct a comparative test on mobile phones, tablet computers and TV products on the market and found that all 13 samples belong to the exempt category in IEC 62471:2006, that is, no blue light hazard, consumption You can use it with confidence.

  However, after 15 minutes of primary and secondary school students' 30-minute game tasks, 5 samples made the subjects feel obvious visual fatigue; 10 samples significantly affected the performance of the user's visual perception function and generated an early warning. The test results to a certain extent indicate that children and adolescents should not watch the electronic screen for more than 30 minutes at a time. After watching for 20-30 minutes, you must take a proper rest to relieve visual fatigue and repair the damage to visual perception.

  In addition, from the evaluation results, in order to protect eyesight, consumers can prefer OLED display and improved LCD display (TFT display), and prefer large-screen electronic display products.

Preventing myopia must first ensure eye hygiene

  The Consumers’ Association stated that the medical community has reached a basic consensus on the "culprit" causing myopia in children and adolescents, that is, children and adolescents with myopia are mainly caused by long-term use of electronic products resulting in visual fatigue and improper posture, effectively controlling the time of eye use and maintaining Correct eye position is the main way to prevent myopia.

  To this end, the China Consumers Association reminds children, adolescents and parents not to worry too much about the harm of blue light to their eyes, not to blindly superstitiously declare the effects of myopia protection declared in the advertisements of anti-blue light products, and to choose appropriate electronic products. At the same time, parents should pay more attention to their children's eye hygiene, use their eyes reasonably, and protect their eyesight. (Finish)