In this work, human lens pathology in different forms of the cataract was studied. Two hundred twenty patients with a cataract (220 eyes) were included in the study. Morphological, immunohystological and immunocytochemical investigations of both lens capsule and substance with antibodies to α- (α-А and α-В), β-, and γ- crystallines were carried out. Diabetic patients revealed a more pronounced expression of α- and β-B crystallin compared with a group of patients with age-related cataracts. Correlation between composition of the crystallines in a lens and its density was demonstrated.