The paper deals with the study of specific features of ocular adaptive reactions under the conditions of the Far North. The author suggests that there should be 3 types of ocular adaptation in the North: (1) and (2) being at the individual level and (3) at the population level. Type 1 adaptation is usually observed within the first months of stay in the North. The ocular status of newcomers is characterized by lower hydrodynamic parameters: a tendency to intraocular vascular dystonia (the hypertensive type) is formed. Type 2 adaptation is generally seen after spending 10 years of stay in the North. Persistent physiological vascular reactions are formed (within the upper normal range). Organic disadaptive changes in microvasculature develop in a third of the new residents in the North. Type 3 hereditary long-term adaptation is observed in the indigenous residents of the North. The most optimum ratios of hemo- and hydrodynamic parameters along with definite changes in anatomic and functional indices form in them, which is reflected in the specific features of eye diseases.