Blood and oxygen supply, respiration and cerebral cortex function especially those cortical parts in which visual analyzer is represented were studied in children and adolescents with myopia and accommodation spasm. It was found that respiration function and oxygen regime in myopia children and adolescents are 2-3 years behind those in normal children and adolescents. Electroencephalogram data show that index of alpha-rhythm in the occipital lobes (especially in the left lobe) and amplitude of alpha-rhythm in the right lobe are lower than in healthy subjects. Delta waves prevail on EEG of myopia patients, especially in the front lobes. Indirect signs of general cerebral dyscirculatory symptoms and dysfunction of the subcortical structures were registered as well as moderate changes in bioelectric activity of the cerebral cortex. 20-day interval hypoxic training in children and adolescents raised efficacy of the external respiration and circulation, normalized bioelectric activity. The majority of the patients improved their visual acuity up to complete normalization.