The paper presents the results of a study of the morphometry of peripheral blood erythrocytes in elderly, senile, and long-living persons on an ASPEK Russian computer cell image analyzer, by applying the programs to measure the sizes of the cells and their hemoglobin count. By examining large amounts of erythrocytes, the use of a current technology provides objective characteristics of not only cell sizes, but also fundamentally new information on hemoglobin count in an individual erythrocyte and on the structure of red blood cells in terms of this indicator. The average diameter and area of a red blood cell population were ascertained to correspond to the generally accepted adult upper normal ranges manually calculated. The composition of a red blood cell population was determined by the distribution of cells containing different hemoglobin levels. The use of the results of the investigation optimizes the detection of patients with impaired hemoglobin formation.