To protect their phones, many people are accustomed to applying protective film to their phone screens. The reporter's investigation found that there are various types of mobile phone films sold in the market. In addition to protecting the screen, some businesses also claim that their phone films can not only prevent peeping, but also "protect the eyes". Are these claims reliable? Some merchants showcase to consumers on their product introduction pages that the privacy film not only has privacy protection functions, but also can "truly relieve visual fatigue, and long-term use will not cause eye fatigue or dizziness". Experts compared the "privacy protection" phone film sold by this merchant with a regular phone film pasted on an electronic screen at the same time. Under a stereomicroscope, it can be seen that the principle of the "anti peeping" phone film is similar to the familiar blinds for consumers, but these window pages are always kept in an open state perpendicular to the screen. When you are facing the blinds, your line of sight can almost pass through without obstruction; However, once you deviate from this vertical perspective, the content you can see will gradually decrease. This also explains why anti peeping films usually appear gray, and the densely packed windows on the screen inevitably reduce screen brightness. Long term use of privacy film can cause visual fatigue. Experts point out that although privacy film can reduce the viewing angle of the phone screen and prevent others from peeking at the phone to a certain extent, it can also significantly reduce the brightness of the phone screen, and long-term use can cause visual fatigue. Some businesses claim that their anti blue light phone films not only protect privacy, but also prevent blue light and protect the eyes. The reporter purchased two mobile phone films for testing. Expert: Most qualified mobile phones and computers come with an eye protection mode. Experts suggest that some phone films claiming to protect vision often profit from concepts and intentionally exaggerate their effectiveness. Generally, qualified mobile phones and computers come with an eye protection mode, which can reduce the damage of blue light to the eyes when turned on. If applying a film, choose a mobile phone film with good transparency and high imaging quality. When using electronic products, scientific eye care is the key to eye protection. (New Society)