Eye protection lamp-can't prevent myopia
Now there are some eye protection lamps that can prevent myopia. If they really have clinical effects in this respect, they should also belong to the category of medical devices. Understanding of medical devices should be based on scientific and systematic clinical trials and reported to the competent department for approval. At present, the eye protection lamps on the market have not been tested in this respect, so it is irresponsible to carry out the propaganda of "preventing myopia" in this case.
Eye protection lamp-danger
First, the white light emitted by the eye protection lamp is too strong. Reading and writing in this light will feel reflective or dazzling, resulting in visual fatigue and decreased vision. At present, all eye protection lamps use fluorescent tubes as light sources, and most fluorescent lamps emit white light. Compared with yellow light, white light has the disadvantage of reflection or glare, so students will feel tired or sore when they look at things under white light for a long time (generally more than 15 minutes). Why is this happening? In fact, the macula inside the human eye (that is, the background color of the eye is yellow) is the most easily accepted yellow light instead of white light, which is the fundamental reason why reading and writing under yellow light will feel soft and comfortable, while under white light it will feel dazzling or tired. Some parents say that the light emitted by eye protection lamps used at home is also yellow. Then, the salesman should ask whether the lamp he uses is a light bulb or a tube. If it is made of a lamp tube and the light emitted is yellow, the promoter can clearly tell him: "This yellow light is emitted when a yellow substance is coated in the lamp tube, and the light emitted by this lamp is still white in essence, while the real yellow light refers to warm light. Only the light emitted by a lamp made of a light bulb is the real yellow light. Therefore, although the light in your house is yellow, it is fake yellow, which is essentially different from the yellow light produced by light bulbs. Seeing things in this yellow light will still be dazzling, but it is slightly better than the white light emitted by other fluorescent lamps. " Second, eye protection lamps made of fluorescent lamps will produce serious ultraviolet radiation, which will do some harm to students' eyes and skin. At present, all eye protection lamps use fluorescent tubes as light sources. Fluorescent lamps must excite fluorescent powder by ultraviolet rays to generate light, and ultraviolet disinfection lamps use this principle to generate ultraviolet disinfection. So all fluorescent lamps will produce ultraviolet rays, including the most commonly used fluorescent lamps. However, why not say that fluorescent lamps are harmful and eye protection lamps are available? That's because fluorescent lamps are generally far away from our human bodies (at least 2.5 meters above), and within the distance of 1-2 meters, the ultraviolet rays generated by fluorescent lamps will cause certain harm to human eyes. If it is within 0.6 meters, the damage will be aggravated, and the distance between the eye protection lamp and the students is definitely less than 0.6 meters, so the ultraviolet rays generated by fluorescent lamps will not cause harm to people, but the ultraviolet rays generated by eye protection lamps will cause great harm to people. Professor Zhou, Director of Ophthalmology, Affiliated Eye Hospital of Fudan University, once wrote in the Morning Post that long-term exposure to ultraviolet rays will cause damage to the lens and retina of the eyes, leading to decreased vision and even blindness! Eye protection lamp
Eye protection lamp 3. The biggest problem with eye protection lamps is that electromagnetic radiation will do great harm to students' brains. The main selling point of the so-called eye protection lamp is that there is no stroboscopic light, which means that the light of this lamp is stable and will not flicker. This is compared with fluorescent lamps. Because the current frequency of the fluorescent lamp is 50 Hz, the light of the fluorescent lamp will flicker (stroboscopic), and this flicker speed is exactly 50 times per second (that is, 100 times). Eye protection lamp is to avoid this flickering feeling. It uses high-frequency electronic ballast to adjust the current frequency to several thousand hertz or even tens of thousands of hertz, that is to say, it adjusts the flashing speed of light to thousands or even tens of thousands of times per second. When the flashing speed of light reaches tens of thousands of times per second, the reaction of human eyes can't keep up with this speed, and then there will be a feeling that the light is stable and not flashing. Illustration: When the bicycle rides slowly, we can clearly see that the wheels are made of steel wire, but when the bicycle rides fast, there is no steel wire at all, only one lap. Therefore, the true eye protection lamp should not flicker without frequency, but with high frequency, which is too high for human eyes to feel. It is this characteristic of eye protection lamp that makes the light it emits more stable and comfortable than fluorescent lamp. However, high-frequency electronic ballast will bring a very serious problem, that is, it will produce high-frequency electromagnetic radiation. High-frequency electromagnetic radiation is harmful to people, especially to the brains of developing students. Many parents know that the electromagnetic radiation of mobile phones is harmful to students, and they want their children to use mobile phones as little as possible, but they don't know the electromagnetic radiation generated by eye protection lamps. Because of their higher frequency and longer use time, the harm is far greater than that of mobile phones.