Abstract: Tear fluid contains a large number of proteins, cytokines and other substances involved in regulating the function and metabolism of a variety of cells in the eye, thus reflecting the individual pathophysiological state. With the improvement of micro-sample analysis technology, tear fluid has become an ideal source for the detection of potential biomarkers of diseases due to its easy accessibility, convenient storage and stable nature. Glaucoma, keratitis, thyroid-related eye diseases, and even some systemic diseases (Alzheimer's disease, diabetes mellitus, tumors) are associated with changes in potential biomarkers in tear fluid, and their detection may provide some clinical reference value for the prevention and early diagnosis of these diseases.(Int Rev Ophthalmol, 2024, 48:  316-320)

Key words: tears, ocular diseases, systemic diseases, biomarkers