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Light and vision health

  日期:2011-11-18  浏览次数:55

 Human knowledge and information, 80% is obtained by the visual organ, so often said, to cherish the same love their own eyes the most precious things. However, according to a recent national survey results of student's health, primary rate of 22.78% of myopia; middle school students was 50.22%, 70.34% high school students, college students, compared with 76.74%, therefore, to curb the rate of myopia imminent.
Visual impact of the health of many factors, including light problem is one of the most important factor. Recall that before the reform and opening up, due to power shortages and economic conditions, our main source of rural students is the kerosene lamps and candles, not the city is nothing but the power light bulbs. Although no accurate statistics, the incidence of myopia but certainly much lower than it is now. Long been overlooked source should be taken seriously enough. Because the human visual system under natural light is gradually evolved, so natural light is the best reading light, the children in natural light during the day and not feel the eyes when reading tired. Primary and secondary students now work more than a day, came home from school should continue to study late into the night. Obviously, the vast majority of primary and secondary school myopia light in the evening occurred when reading. So, visual health effects of light exactly is the problem there? Analysis showed that causes students to the high incidence of myopia are two main culprits, one strobe, and the other some surprising is too light.
Strobe light is electric flux fluctuations in the depth of the jargon is called light output fluctuations, fluctuations in the greater depth, the greater the depth of strobe. Electric light under the action of the AC turn on and off resulting changes, just not continuous. Flicker once or twice per second, will give cause uncomfortable feeling. Electric light the stroboscopic effect will cause visual fatigue, migraine headaches, damage to the eyes of young people growing form of myopia.
Ordinary fluorescent and incandescent light will be emitted 100 times per second, blink frequency, although the change in perception of light and dark eyes, for this is not too obvious, but to work long hours in this light environment, the human eye can easily fatigue, resulting in myopia. In addition, if the light using the computer, usually inductive ballast fluorescent screen of strobe and flashing overlap of frames, the formation of optical resonance of the human visual system is more damage. Because of this, the European Electrotechnical Commission early in 1997, prohibits the installation of a computer screen in office fluorescent lights with magnetic ballasts to protect the health of the computer operator.
Energy-saving lamps and fluorescent tubes by high-frequency electronic ballast combination. Basic principle is to improve the high low strobe strobe. The main function of electronic ballasts is to accelerate the speed strobe will flash 100 times per second, the frequency increased to several thousand times per second, or even tens of thousands of times blinking, flashing much faster than the human eye's response rate, although in this light study, office, feeling a short time would be better than the low-frequency source flash, but will still be in the human eye the optic nerve cells under the effect of high-speed strobe light fatigue. Therefore, the energy-saving lamps can not fundamentally solve the stroboscopic vision caused by health problems.
For causes students to the high incidence of myopia is another major culprit - too light, many people feel do not understand, most people believe that myopia is due to light or excessive use of the eyes caused by long-term. Therefore, many people in order to protect vision, myopia prevention, indoor and learning will simply add illumination with light. The results failed to protect the eyes, but still resulting in myopia.
Why is light and strong it can also lead to myopia? It turned out that if the light around the eyes too, in the light entering the eye, due to light stimulation of the sensory retina cells, conduction through the optic nerve, causing scleral ring of smooth muscle in the long-term, fatigue contraction, so that the pupil narrow, limiting the amount of light entering the eye. With young people are in the growth stage, eyes and other body organs, has not yet fully mature, easily over-stimulated by external factors change. Long-term stimulation by light the eye, the eye can cause functional changes, so the regulatory function of eye disorders, thus becoming nearsighted.
Illumination light to indicate the extent of the work surface is the unit of measure, according to the Ministry of Construction on the promulgation of national standards was "architectural lighting design standards" GB 50034-2004, the value of residential building standards for general illumination lighting venues is 100 lx, writing, reading as 300 lx, school classrooms, reading the standard value for the desktop illuminance 300 lx. However, the market value of the study lamp illumination measured generally more than 700 lx, larger power actually 1000 lx, far exceeding the national standard. Long-term high-intensity light vision and healthy environment for students to become killers, parents to care for the purpose of blindly "bright" has become an accomplice.
In recent years, with the development of semiconductor technology, a new type of LED light source is rising rapidly, the DC power source to solve the long-troubled areas of the strobe light problem, the brightness can be easily adjusted according to need, and thus solve the the light is too strong or too weak problem. In addition, the semiconductor light source is also harmful to the skin without ultraviolet and infrared components. Semiconductor light source is expected to replace traditional light sources will soon become the mainstream of student learning to use lights.


Copyright:BERYLPOP Electric Equipment Factory    Adress: TuQang Bld, YongAn Road,DongFeng Town, ZhongShan City, GuangDong Province,P.R. China.