Abstract: the occurrence of low vision in children, especially myopia, is inseparable from the genetic basis. Studies have shown that the father’s low vision can often be passed on to the next generation through genes, which makes the father’s abnormal refraction a risk factor for children’s abnormal refraction. In recent years, with the development of society, the popularity of electronic products and the decrease of outdoor activities, the incidence rate of low vision of preschool children has been increasing year by year and the trend of
is ahead. This paper is adapted from the research status and countermeasure analysis of low vision of preschool children in community (click to view the full text and all references). What does
mean low vision and its diagnostic criteria
Low vision often means that the far vision of the naked eye can not reach the normal standard, which is also called poor vision and low vision. In some domestic studies, it is also called abnormal vision. Myopia, hyperopia, astigmatism and other refractive errors, as well as amblyopia and strabismus can lead to low vision. Due to the imperfect visual development of preschool children, the standard of low visual acuity is different from that of school-age and adults.
at present, the standards adopted by most domestic studies are: vision < 0.6 for children aged 3, vision < 0.8 for children aged 4, and vision < 1.0 for children aged 5 and over.
the prevalence of low vision in preschool children in China
most domestic research results show that the detection rate of low vision in preschool children is more than 5%, mostly 5% ~ 20%. In some studies, the detection rate of low vision is even more than 30%, but some studies have found that the detection rate of low vision in preschool children is only 1.93%.
the results of vision screening of 31430 preschool children in Beihai City from 2004 to 2011 showed that the incidence of low vision was 25%, and the detection rate of low vision was the highest in 2009.
why do preschool children have low vision? Often
● heredity – mainly due to their father?
children often have low vision, especially myopia, which is inseparable from the genetic basis. Studies have shown that the father’s low vision can often be passed on to the next generation through genes, which makes the father’s abnormal refraction a risk factor for children’s abnormal refraction. Guggenheim studied the myopia of twins. The results show that myopia is indeed determined by genetic factors to a certain extent. The results of vision screening for preschool children also show that parental ametropia is a risk factor for low vision in preschool children.
● birth history – History of oxygen inhalation, history of asphyxia, causes of abnormal birth weight?
research shows that full-term birth is a protective factor for children’s vision. In the study, Wang Bin found that the history of oxygen inhalation in infants is a risk factor for children’s low vision. In addition, some studies have found that a history of asphyxia at birth and a weight of less than 2000g or more than 4000g are the risk factors of abnormal refraction in children.
● eye habits and contact with electronic products – shortening time is the king.
at present, with the popularity of electronic products such as TV and mobile phone, its impact has also penetrated into children’s groups. Many children have been addicted to watching TV programs and mobile games for a long time, and its stimulation has caused adverse visual environment and abnormal visual stimulation. In addition, the study found that the eye distance and duration were closely related to the occurrence of myopia. Children use their eyes for a long time, which is easy to cause spasm of eye regulation and fatigue. This visual fatigue caused by long visual proximity time can not be alleviated, which is one of the factors affecting low vision.
● sleep time and outdoor activities – sleep 10 hours a day. Outdoor light is indispensable.
adequate sleep is conducive to the visual development of preschool children. Children sleep less than 10h a day, which can not effectively alleviate visual fatigue and cause low vision. Outdoor activities and natural light can promote the development of children’s vision. Studies have shown that the increase of children’s outdoor activities per week is related to the decrease of the incidence of myopia. The possible biological explanation is that for outdoor natural strong light, the retina will release dopamine that inhibits the growth of axis length. Animal experiments also show that natural strong light can inhibit the development of form deprivation myopia.
● nutrition and eating habits – protein, vitamins, zinc, chromium and calcium are indispensable.
childhood is the key and sensitive period of visual development. Malnutrition will cause vitamin and trace element deficiency, cause nutritional disorders, and affect the normal development of visual system. It is found that nutrition plays a very important role in children’s visual development. Malnutrition is closely related to the occurrence of refractive abnormalities in preschool children. High protein and high vitamin diet is the protective factor for preschool children’s refractive development, while the deficiency of trace elements such as zinc, chromium and calcium is the risk factor affecting children’s refractive development.
● daily lighting – neither light intensity nor weak light can
good lighting is one of the important conditions for preschool children’s visual development. Animal experiments have shown that daily lighting patterns can regulate eye development, especially related to many mechanisms of refractive development. Strong family light is a risk factor for children’s visual development, and poor lighting conditions will make children’s eyes too close to the object, resulting in excessive tension in regulation and low vision. Some families and kindergartens do not pay attention to lighting conditions, which affects the normal development of vision. In addition, other studies have also shown that there is often a statistical correlation between family lighting and low vision.
environmental support for preschool children’s vision care intervention
● since appropriate lighting is of great significance to children’s vision development, kindergartens and families should have a good eye environment, and various facilities of kindergartens must strictly comply with the requirements of national kindergarten design specifications, such as lighting of kindergartens and families, height of tables and chairs Font size and printing quality of books.
● the kindergarten shall provide sufficient outdoor activity time. At present, preschool children spend most of their time in kindergartens. It is difficult for parents to take their children for outdoor activities in the rest of the time due to busy work and high pressure. Therefore, it is particularly important to ensure children’s outdoor activities in kindergartens. In China’s technical code for children’s eye and vision care