The prevalence of myopia is growing worldwide, and myopia is becoming a major epidemiological problem. In 2000, according to the latest studies, 1406 million people (i.e., 22.9% of the world’s population) suffered from myopia, and 163 million people (i.e., 2.7% of the world’s population) suffered from high myopia. In 2050, a total of 4758 million people worldwide (49.8% of the world’s population) are expected to be myopic, and 938 million people (9.8% of the world’s population) are expected to suffer from high myopia [1]. The prevalence of this refractive error varies according to age, ethnicity, and geographical locality [2]. High myopia is associated with comorbidities that increase the risk of severe and irreversible loss of vision, such as dense cataract, retinal detachment, subretinal neovascularization, and glaucoma [3–۵]. Growth in the prevalence of myopia leads to the growth of socioeconomic stress in society. It is very important to look for the reasons for the growth of myopia prevalence in the population and to find ways to reduce the occurrence of myopia and its progression due to the increase of myopia occurrence in society, as well as the potential severe health and social consequences. According to the outcomes of the studies carried out in recent years, lifestyle can influence the onset and progression of myopia. Physical activity and stays in daylight have a possible protective effect [6–۸], while near work is a risk factor [9, 10]. As previously mentioned, the prevalence of myopia is dependent upon a number of factors. Therefore, we decided to map this situation in the Central European population of children in the age range of 11 to 17 years. Biometric examinations of both eyes and examinations of central visual acuity of both eyes are performed at regular, six-month intervals. At the same time, questionnaire surveys are carried out, oriented towards the method of spending leisure time. We concentrate primarily on the development of the axial length of the eyeball at particular periods of time and on the presence of any risk, or protective factors affecting the growth of the axial length of the eyeball. Our research is conducted in cooperation with specialists involved in physical education and prevention, who evaluate the ascertained data on a continual basis and prepare preventive programs for preschoolaged children.