A 3-year-old child with myopia of 900 degrees can correct his/her myopia and improve his/her visual acuity by wearing framed glasses or keratoplasty lenses, and at the same time, he/she should pay attention to eye hygiene and avoid strenuous exercise to prevent deepening of his/her myopia or leading to detachment of the retina, or even blindness. As a 3-year-old child with 900 degrees of myopia is highly myopic and can experience a significant decrease in vision, the child can be corrected by wearing frames or corneal reshaping lenses after the optometry test to improve his/her vision and avoid affecting his/her life and study. Children also need to avoid long time to avoid long time to play cell phones, computers, television and other electronic products, resulting in eye fatigue, appropriate rest with eyes closed, in order to control myopia to avoid continued growth. Due to the 3-year-old child myopia 900 degrees, the child’s eye axis prolonged, the retina is thinner, more flaccid, so you need to avoid strenuous exercise, otherwise it can cause retinal detachment, resulting in children’s vision loss aggravated, and may even lead to blindness. At the same time, parents of 3-year-old children with 900 degrees of myopia should bring their children to the hospital for examination on time to avoid lesions on the fundus of the eye. It is recommended that children with high myopia should consult a doctor in time to evaluate their condition and under the guidance of the doctor.