Low vision seriously affects life, work and study. Children with low vision not only have a huge impact on their future lives, but also become a heavy burden on their families and society. Low vision can cause autism, and has a huge negative impact on a child’s personality molding. The best time to treat weakness is before the age of 6, and it is difficult to cure it after the age of 12. So severe amblyopia must seize the golden time for treatment and be treated as early as possible. Definition:Severe amblyopia refers to the amblyopia caused by high refractive error, monocular strabismus, nystagmus, cataract surgery, etc. It is called severe amblyopia. 0.2 or below low vision can seriously affect the normal life, study and work, but most of them can improve their vision through amblyopia training to improve their life and study ability greatly, and this paper refers to the children with visual acuity of 0.2 or below, which can be improved through the training of increasing the visual acuity. In this paper, children with visual acuity of 0.2 or below, which can be improved through visual acuity training, are called low vision children. Second, the principle of low vision training for children with low vision (a) the nature of low vision: some congenital causes (such as congenital cataract, strabismus, nystagmus or high myopia and high hyperopia, high binocular refractive error, etc.) leading to the visual cells are in the state of inhibitory sleep or dysplastic atrophy (i.e., sleeping, atrophic state). (ii) The basic principle of treating low vision: removing the cause of the disease, waking up the sleeping cells with special color light, and forging the atrophied vision with threshold icons. (C) a variety of therapeutic instrument to improve the low ability to increase the principle of vision: 1, the threshold icon to increase the function of vision: is the most effective direct function to improve eyesight, “threshold” that is, the threshold, that is, the child just can see clearly, but there is a certain degree of difficulty in the doorway, over this hurdle, the eyesight will be improved. (1) Threshold “E” or “C” icon: suitable for children over 3.5 years old (2) Threshold grating (visual physiology) icon: suitable for children under 2.5 years old, uncooperative children (3) Threshold image icon: suitable for children aged 2.5-3.5 years old, able to recognize the image of the Children 2, RGB color light vision enhancement function: is the most effective wake up the visual cells and indirectly increase the function of vision. Can wake up the fundus retina RGB three kinds of visual cells (sensitivity) and indirectly increase the vision; 3, RGB eye sensitivity to increase the vision: the use of RGB color light to wake up the sleeping visual cells, the use of color and light position changes in the training of focusing sensitivity. Difficulties, Methods and Possibilities of Vision Enhancement Training for Children with Low Vision (1) Difficulties of Vision Enhancement Training for Children with Low Vision: The effect of vision enhancement training for children with low vision depends on three aspects: whether the cause of the disease is removed completely, the age of the child at the time of the treatment, and the vision enhancement training instrument. However, it is difficult to train children with low vision during the highly sensitive period due to uncooperative age, incomplete removal of the cause of the disease, and failure to use efficient equipment. Difficulty 1: The younger the child is when he/she starts visual enhancement training, the more effective the training will be. However, the younger the child, the less cooperative he/she is, and the more difficult it is to improve the visual enhancement effect. This contradiction must be resolved in order to achieve good results. Difficulty 2: The higher the number of generations of vision enhancement training equipment, the more functions, the higher the fineness, the better the effect, but the more difficult for children to cooperate. This contradiction must be solved in order to achieve good results. Difficulty 3: the cause of the disease is difficult to completely remove: such as strabismus correction is not in place or recurrence, cataract after surgery, high myopia, hyperopia, such as optometry, lens wear uncooperative and so on can significantly reduce the efficacy of the treatment; (2) severe amblyopia treatment program: 1, early: that is, as early as possible to start the treatment: amblyopia is a visual dysplasia, like a twisted sapling, the earlier the treatment the easier to recover. 2, mirror: that is, the reasonable wearing of glasses: the requirement of the whole day Wear them all day long (wearing them at times or not wearing them at times will reduce the therapeutic effect or even be ineffective). Note: farsightedness or astigmatism first wear glasses visual acuity is mostly worse than not wearing glasses, can feel the ground uneven, dizziness or shaking, is normal, insist on wearing 3 to 7 days to adapt to, visual acuity will rise. And myopia first wear glasses visual acuity is good, but with the development of myopia, visual acuity will become worse and worse. 3, instrument: that is, the use of amblyopia instrument treatment in line with the condition.