Correct use method of desk lamp, you know?

Many parents to buy the lamp that shield an eye to children, in order to protect the eyesight, in fact, these whether there is light eye protection proved effective, scientific evidence is lacking. So, in order to protect the eyesight, the key is to learn how to correctly use the desk lamp, and not just in the hope of eye protection lamp. That how to correctly use desk lamp? Here we come together to find the next:
First, lighting degree to the right. If the degree is too low, according to the book of the light is dark, we do not easily see the handwriting, it will cause visual fatigue, a long time will lead to myopia, then treat myopia becomes every day will do. If the lighting degrees is too high, too strong light passes through the white paper reflect back to our eyes, produce glare, make the pupil continues to shrink, and then cause eye pain and headache. In general, 25 watts, 45 watt incandescent lamp brightness is the most suitable.
Second, the height of the desk lamp is also very important. Usually, the eyes from the book of 30 cm, can see the handwriting, nor excessive fatigue, this projection, the lamp height from 40 - 50 cm more appropriate written, so as to ensure adequate reading lighting, the surrounding environment has a certain brightness. If the lamp is too low, will cause the light to a small range, while the surrounding is dark. Lost for Yuanwang referents, will make the eye the control systems are in tension compression state of near, easy to make eye fatigue, and the rapid accumulation, caused by "light myopia". If the lamp is too high, the light will shine directly into our eyes, produce glare; at the same time, light will cause light onto the retina close retention phenomenon, will make the eye muscle contraction, accelerate declining eyesight, so usually to treat myopia knowledge to be mastered.
Third, the bulb size to with the lampshade matching, to ensure that the lighting just arranged in the lamp shade, avoid direct light our eyes.
Fourth, use the white bulb. Scientific research has proven that, our vision is best, under white light so, choose emits gentle uniform white incandescent lamp or frosted lamp, and don't choose color lamp.
Finally, table lamp placement on the eyesight also have a great impact. Because most people are right-handed, so, the lamp should be put in the body in front of the left, writing not because of hand occlusion formed a shadow on the paper, according to the paper on the light is not reflected in our eyes and produce glare.
Use
China alternating current for 50Hz, namely 50 changes per second. So the direct use of alternating current electric lamp, are flashing, flashing frequency is 100 times / sec, is the grid frequency doubled 100 times per second, that is, change.
Changes in visual sensory can be felt within 30Hz, the light changes 100 times per second (from the Ming to darken, and then by the dark Bian Ming,...... Although not) to be our perception, but research has said, these changes (flashing) to the human eye, there will be effect.
Such as glare effect on the eye, eye pupil shrinks; for the weak light, the pupil.
So the direct application of the alternating light hurts the eyes (refers to the often use electric lights the students read a Book). Someone invented high frequency lamp, is thousands of times per second change, because the human eye can't change, do not feel the change, so it can be said to be "unchanged", achieve the purpose of protecting eyes. The ordinary 50Hz alternating current into high frequency alternating current, the use of electronic frequency. High frequency lamp, the actual first 50Hz alternating current into high frequency alternating current, and high frequency alternating current lighting.
But the electromagnetic radiation of high frequency electric will also increase, namely electromagnetic high frequency electromagnetic lamp radiation than ordinary incandescent lamp, fluorescent lamp radiation, may also be caused by another injury. In addition, the high frequency is not equal to not flash flash.
(a), warning:
1 the use of paper, cloth and other flammable items not near the tube (to avoid fires) 2 installation or wipe the lamp, please be sure to cut off the power supply (to avoid electric shock)
(two), attention:
1 please lamp using the specified power (avoid shorten lamp life of 2) when the lamp tube is inserted into the installation please confirm whether the lamp holder (avoid falling injury) 3 please do not crash tube to avoid injury (injury to avoid damage) please do not touch the lamp lights after 4 use or (to avoid scalding) 5 please do not use in high humidity or high places.
(three), the use of attention to matters:
1 in the use of low-temperature, fully lit lamp needs a period of time, but also lit light flashes, this situation is normal. The 2 lamp when you start using the electrode near the top, black or the use of a small dot, belongs to the normal situation.
Buy
In the lamp market, more and more parents are eager to protect eye lamps for child health and safety. However, in the face of different styles, more and more attention to eye protection desk lamp appearance, parents also can identify them? So what desk lamp is not a real eye protection desk lamp?
1, energy saving lamp as the light source lamp.
Those who use energy-saving lamp as the light source, there will be a stroboscopic. The research shows that, the electromagnetic radiation, strobe is one of the biggest culprit causing juvenile myopia.
2, the use of table lamp high frequency electronic ballast.
The use of high frequency electronic ballast, stroboscopic although eyes don't feel. However, it is still in the form of waves exist. Moreover, the electromagnetic radiation emitted by a high-frequency electronic ballast, will seriously damage the developing brain of children, also seriously damage the retina.
3, the height should be more than 40 centimeters of desk lamp.