Screen protector that filters blue light

Many screen protectors claim to filter out blue light, but in testing they were as effective as food filters.

Blue light filter patches are mostly advertising, with little effect. Photo: NYT .

Faced with reports of eye damage from blue light from electronic screens, patches advertised to combat this phenomenon have also been born. With new functions, they are sold at a much higher price than conventional accessories. However, the actual effect has not been proven.

A reporter from China’s CCTV randomly tested a series of products priced between 10 and 140 yuan (8,500 and 120,000 VND). An experiment at Beijing Jiaotong University, experts ran tests on specialized equipment and found that the “anti-blue light” function of some samples was only as good as food wrap.

“I put the sticker in front of a spectrometer. It showed a slight reduction in the intensity of blue light. When I put the food filter on, its full-spectrum suppression effect was exactly the same as the protective glasses,” concluded Chen Zheng, a professor in the Department of Engineering Physics at Beijing Jiaotong University.

This person believes that screen protectors are completely incapable of filtering blue light. However, compared to plastic wrap, it is thicker and harder, so sticking it on the phone can achieve a protective effect.

According to experts, the level of blocking harmful rays is also related to the brightness of the phone screen. “The blocking value of 20 or 50% is closely related to the backlight module and the brightness setting. First, how much blue light the phone emits, then comes the blocking part. For example, smartphones emit harmful rays at a high level. The screen protector blocks up to 50%, which is still at a harmful level. This is basically useless,” said Vuong Quoc Viet, Professor of Materials Science and Engineering, University of Science and Technology Beijing.

Regarding advertisements for patches that block 99-100% of blue light, experts say that the main color emitted by phone screens is blue rays. If they are really blocked, smartphones will have serious color cast and distorted visual experience.

Currently, there are no national health standards for the level of blue light emission from electronic device screens. Some companies advertise this feature of their screens, certified by international organizations such as Dolby Vision or TUV Rheinland. However, there is still a lack of scientific research showing the actual effectiveness. The same is true for the screen protector industry. Adding anti-blue light microparticles often reduces the light source, causing a yellowing.

Medical experts still believe that the most effective way to limit the harmful effects of blue light is to reduce the use of electronic devices for long periods of time. The short wavelengths of the above rays cause eye strain, making myopia worse.

Source: https://znews.vn/dan-man-hinh-co-loc-duoc-anh-sang-xanh-post1582973.html