Abstract: The ophthalmological terminological system is considered to be formed, but insufficiently studied from the point of view of synonymy. Often, the term acquires duplicate double or triple names — quasi–synonyms, which the authors consider professional jargon and "folk" terms.
The work represents the next stage of an earlier study, the subject of which is ophthalmological terminology. The purpose of the study is to explain the nature of the term via the formation of a nomenclature generally accepted term, to find possible quasi—synonyms for this term, explaining their presence or absence. The object of the study is the term "glaucoma". The author considers the structure of a triple row of duplicate names from the point of view of concept theory: the nomenclature name is in the center and is the conceptual core, in the nuclear zone — professionalism—jargonisms, folk terms are located on the periphery. The history of the term "glaucoma" is considered, an attempt is made to identify quasi-synonyms and establish the relationship between the name of the disease and the perception of the disease by patients, through an experiment. 93 patients with the diagnosis of "open-angle glaucoma" of the initial and advanced stages took part in the experiment. The patients were offered a questionnaire (12 questions, answers: "yes", "no", one additional question). The scientific novelty lies in the fact that due to the insufficient knowledge of the problem of nominating duplicate ophthalmological terms, an experiment was conducted that allowed us to determine the range of descriptors used by patients to determine their condition. The detailed answers confirmed the scientists' guesses that the etymology of the term "glaucoma" may be related to the use of a descriptive (cloudy blue-green) in ancient times. In addition, the results of the experiment revealed that the term "glaucoma" has neither synonyms nor duplicate names, which was obviously influenced by the etymological factor, the euphony factor, as well as the identity factor.
In the future, it is necessary to study the influence of various factors on the appearance of duplicate terms and their distribution into groups: nomenclature terms, professional jargonisms, "folk" terms.