The global prevalence of myopia in adults varies between 20—50% in Europe and the US and 60—90% in Asian countries. According to WHO, myopia is one of the five leading causes of blindness and low vision in the world. Prevention or deceleration of myopia progression is an important public health problem. In recent years, orthokeratology (ortho-k) contact lenses worn at night have been found effective in slowing down the progression of myopia, however, the follow-up period in related studies is no longer than five years. Aim — to investigate the effects of long-term (10 years) overnight wear of ortho-k lenses on the dynamics of axial eye growth in children and adolescents. Material and methods. This is a prospective cohort study of the effects of ortho-k lenses on the dynamics of anterior-posterior elongation of the eyeball in 84 patients (168 eyes) aged 7 to 16 years and diagnosed with progressive myopia of 1.0 to 7.0 diopters. Patients were examined every three months, including the slit lamp examination to detect possible side effects of lens wear. Results. The study proves the decelerating effect of the method on disease progression: the average 10-year increase in the axial eye length was 0.7±0.02 mm that corresponds to myopia progression of 2.4 diopters. A comparative analysis of the annual axial eye growth depending on patient age and the degree of myopia at baseline was performed. The increase was found to be generally greater in young children with higher initial myopia. Conclusion. Long-term wear of orthokeratology lenses is able to slow down the axial eye growth, i.e. the progression of myopia.