When looking at a near object, in order to make the object accurately imaged on the retina, the ciliary muscle circumferential fibers start to contract, the crystal suspensory ligament relaxes, the lens bulges out in front by its own elasticity, the lens convexity becomes larger, the refractive power is enhanced, so that the scattered light emitted from the near object can also be imaged on the retina, and the human eye can see the near object clearly. The regulation of the eye is very closely related to age. The older the eye is, the less the crystal adjustment power is, and the farther the eye is from the near point. When the eye is used for long periods of time at close range, the regulation of the eye is overused and there is not enough residual regulation for backup, so the eye is easily fatigued and forms pseudomyopia. Over time, the front and rear diameter of the eye becomes longer, forming true myopia, serious vision loss, and some develop into high myopia. The most important reason for the formation of myopia in students is the prolonged use of eyes at too close a distance. Teach children to achieve the correct posture, head and neck vertical, body straight, eye line of sight to be at right angles to the plane of the book to. Pay attention to the three distances: one foot, one fist, one inch. That is, when reading and writing, the distance between the eyes and the book should be kept more than one foot; between the body and the desk to maintain a fist distance; when holding a pen hand and the tip of the pen to maintain a distance of one inch. Second, continuous long time use of the eyes Classroom work is too heavy, in order to complete a large amount of homework, continuous reading and writing for several hours without rest. This continuous use of the eyes for a long time, so that the eye vision is overburdened, there is no time to relax and rest, the internal and external muscles of the eye continue to be tense, poor circulation IOP increased spasm and gradually formed myopia. Third, walking, reading books when riding in a car Walking hands will often shake, when riding in a car will be upside down from time to time, the distance between the book and the eyes constantly change, the two eyes look at the target move more times, the visual center received a blurred image. To see the font on the book, you have to bring the book closer to your eyes. In a near-sighted environment, you must also constantly change the strength of the eye regulation in order to see the font clearly. Continuous tension in the intraocular muscles can easily cause visual fatigue and regulatory spasm. Fourth, in the strong light or daylight reading, writing Light is too strong or too weak will bring adverse effects on the eyes. People regulate the light entering the eye by dilating or reducing the pupil. We only need 100 meters of candlelight to read and write on a daily basis, while reading in the sun, the illumination can reach 80,000 to 120,000 meters of candlelight, which is 800 to 1,000 times more than the daily illumination. In addition, because the light is too harsh, look for a while, you feel that there are black shadows everywhere in front of you, which is the afterimage effect of the retinal macula stimulated by strong light. Long-term reading in bright light, excessive regulation of the intraocular muscles will contribute to the occurrence and development of myopia, and the damage caused by bright light to the retina, especially the macula, will reduce visual acuity and even cause permanent vision loss. Long-term reading in strong sunlight, strong ultraviolet radiation is also prone to damage the cornea and lens. Five, watching television for a long time An important reason for the formation of myopia. The rays radiated by the television tube can consume a large amount of the retina in the retinal violet. And now people are spending more time with the TV, which is more damage to students’ eyesight. When watching television, special attention should be paid to protecting the eyes. The following points should be noted: 1, the placement of the television set and eye distance to science: television sets should be placed as far as possible in the corner of the softer light, the height should also be appropriate. The center of the TV screen should be on the same level as the eyes or slightly lower. Eye and screen distance should be more than 6 times the diagonal of the screen. In addition, watching TV should be sitting directly in front of the screen, if sitting on the side, the perspective should not be less than 45 degrees. Can not lie down to watch TV. 2, the contrast of the TV and the brightness of the room should be correct: when watching TV, the contrast should also be moderate. When watching TV, the light in the room should be neither too dark nor too bright. 3, strict control of the time spent watching TV: after every 30 minutes of watching, take a break from your eyes. Or close your eyes, or do eye exercises (eye exercises), you can also do a little eye exercise, the best use of the time to broadcast commercials to the outdoors for a change of air, look into the distance. Six, play video games too much video game screen flashing pattern is extremely blinding, and the game program speed is too fast (such as racing programs), variable, in order to see clearly, the eye ciliary muscle needs to constantly change the adjustment, so it is easy to cause visual fatigue, some will also cause dizziness, blurred vision, and eventually form myopia or deepen myopia degree.