Do your blue lenses work?

Online classes, telecommuting, online shopping “Cloud life” has become the normal of people’s work and leisure, which not only increases the convenience, but also increases the time people spend staring at the electronic screen, and increases the risk of eye health damage. According to the latest data, China’s mobile Internet users spend up to 144.8 hours per month. In this context, anti blue light lenses with the selling points of protecting eyes and relieving visual fatigue are in great demand.

is anti blue lens really effective? In the face of a wide range of anti blue light glasses on the market, how to choose and buy them correctly? In response to these problems, the reporter interviewed relevant experts.

to prevent blue light, we must first understand what is blue light. LED and LED light source used by Cai Jianqi Research Institute are the standard light sources for LED and LED display in China.

it should be noted that not all blue light is harmful to human body. Cai Jianqi said that the human eye has a very low tolerance to blue light radiation in the 400-440 nm wavelength range, and when the light intensity reaches this threshold, it is easy to produce photochemical damage. However, in the range of 459-490 nm, blue light radiation plays an important role in regulating the physiological rhythm of the human body. It can affect the secretion of melatonin, and then affect the body’s biological clock, alertness and emotion.

Cai Jianqi told reporters that at present, there are two kinds of problems in the ineffective blue light protection products on the market. One is that the blue light in the vulnerable area of the eye has little protection effect; the other is over protection, which blocks the blue light spectrum within the beneficial band range, making the blue light beneficial to physiological regulation unable to enter the human eye. At the same time, the lens color is yellow, prone to color deviation, aggravate visual fatigue and even induce myopia risk.

in order to further standardize anti blue light products and make all kinds of products play a role in protecting eye health, recently, the new national standard GB / T 38120 has been formulated and officially implemented in July this year. As the drafter of the standard, Cai Jianqi introduced that based on the difference in the influence of different bands of blue light on the human body, the blue light transmittance of each band of the product was required respectively. For example, in the range of 415-445 nm, the light transmittance should be less than or equal to 80%, and above 445 nm, it should be more than 80%.

“by limiting the blue light prevention products, it can not only effectively shield the blue light which has a health and safety risk to the human body, but also can effectively pass through the band blue light which can regulate the human physiological rhythm. During the period from formulation to release and implementation of the standards, many enterprises have taken the initiative to improve the quality of products and products according to the new standards. ” Cai Jianqi said.

the implementation of the new national standard provides guidance for consumers to choose effective anti blue light lenses. The protective effect of anti blue light lens needs to be tested by professional instruments and equipment, such as spectrometer, etc. consumers can not test it by themselves. For anti blue light glasses, if considering purchasing, Cai Jianqi suggests that consumers choose products with similar statements such as “conforming to GB / T 38120 optical safety requirements” or “meeting GB / T 38120 optical safety and health requirements” on the product packaging.

in the digital society, people are increasingly inseparable from the electronic screen. In order to protect the health of eyes, many people fall into the misunderstanding that anti blue light glasses must be worn for a long time. In this regard, Cai Jianqi explained that wearing anti blue light glasses also needs to vary from person to person and from time to time.

if you watch the screen for a short time every day and there are intervals, pay attention to rest and do not wear anti blue light glasses. It is suggested to wear anti blue light glasses because of the long-term cumulative effect of blue light.

in this regard, experts suggest that in terms of screen selection, as the display device can not meet the visual health requirements, the large screen can be preferred. For example, at present, many mobile phones or tablet computers have the function of screen projection. If conditions permit, it is recommended to use the projection function to watch on the large screen. In terms of using distance, the distance from eyes to TV and computer screen should be kept at more than times the diagonal line of the screen, while the screen of tablet computer and mobile phone should be smaller. On the basis of seeing clearly, the distance should be more than 45-50 cm. In terms of screen brightness, for mainstream display products purchased in recent three years, it is recommended to set the screen brightness at 60% – 80%, and for the display screen used for more than three years, the screen brightness is recommended to be set at more than 80% – 90%.

in addition, appropriate ambient light should be maintained in the surrounding environment. When looking at the screen, the environment is not the darker the better, but need to be supplemented by lighting, general home lighting can meet the requirements. Similarly, when using a desk lamp at night, keeping the main light on in the room is good for eye health. In terms of the duration of eye use, it is recommended to take a 10 minute interval of visual acuity or close eyes. If conditions permit, teenagers under the age of 10 should look far away for 10-15 minutes after watching the screen for 20-25 minutes. People over 10 years old should also look far away for 10-15 minutes after watching the screen for more than 30 minutes. Focus