Based on the analysis of the classifications of endocrine ophthalmopathy (EOP), described in the literature and their many years' own observations of patients with this condition, the authors propose their classification. EOP is divided into 3 forms, 2 of which may be characterized by the compensation of a pathological process and by the stages of its development (from active cellular infiltration to end-stage fibrosis). The former of the forms (exophthalmic thyrotoxicosis) frequently regresses during endocrinological therapy. Edematous exophthalmos and endocrine myopathy may be complicated by an irreparable loss of visual functions and working capacity. These patients should be treated by ophthalmologists, by obligatorily keeping in mind the compensation of a pathological process and the stage of its development.