Myopia is one of the most relevant problems in pediatrics. One of the starting mechanisms of myopia is accommodation disorders. With an imbalance of autonomic innervation of the ciliary muscle, the process of accommodation is disrupted, which leads to the development and progression of myopia. The purpose of this study was to assess the features of vegetative homeostasis in teenagers with myopia. During the work, a survey was conducted among 300 teenagers of 15 years old, in schools of Yakutsk. The main group was 114 teenagers with myopia, the control group was 186 adolescents without refraction disorders. According to cardiorhythmography, teenagers with myopias have a high level of centralization of heart rate management, a relatively high level of activity of the sympathetic department of the autonomic nervous system and low activity indicators of the parasympathetic department of the autonomic nervous system. Sympathicotonia was much more common in young men than in girls. Sympathicotonia, functional tension and overvoltage, increased cardiovascular response to an orthostatic probe, excessive and insufficient, and paradoxical vegetative provision are characteristic of teenagers with myopia. The results showed that teenagers with myopia of both genders have autonomic nervous system imbalance.

The state of health of children is one of the indicators of the quality of the environment, social well-being and the level of health of the country. The purpose of this study was to assess the physical development of children and adolescents. To assess the physical development of children and adolescents living in Yakutsk and the central regions of the Republic of Sakha (Yakutia). 1,305 children aged 8-15 years old were examined. Physical development was investigated using anthropometry and handgrip test according to generally accepted methods. The following results were obtained: according to anthropometry, modern schoolchildren have secondary physical development. According to our data 11, 12-year-old girls are higher than boys of the same age, and from the age of 14 the body length of boys exceeds the body length of girls. Body weight indicators do not have reliable differences in gender, however, at the age of 13, the body weight of Russian boys is significantly more than the body weight of Yakut boys. Russian girls have higher power opportunities in all age categories than Yakut girls. The power capabilities of Russian boys of prepubertal age belong to high values of physical development. The level of dynamometry in all age categories belongs to the 90centile corridor, which indicates high physical development in girls of Russian nationality. For girls of Yakut nationality, only at the age of 10 and 12, power capabilities are higher than average values. Thus, children of Russian nationality living in the Republic of Sakha (Yakutia), functional indicators (handgrip test) exceed average values.