Purpose: To explore whether unilateral relapse of Bechets disease uveitis (BDU) causes differences in the tear proteome between the diseased and the contralateral quiescent eye.\n\nExperimental design: To minimize interindividual variations, bilateral tear samples were collected from the same patient (n=15) with unilateral relapse of BDU. A data-independent acquisition (DIA) strategy was used to identify proteins that differed between active and quiescent eyes.\n\nResults: A total of 1,797 confident proteins were identified in the tear samples, of which 371 are also highly expressed in various tissues and organs. Sixty-two (3.5%) proteins differed in terms of expression between tears in active and quiescent eyes, similar to the number of differentially expressed proteins (74, 4.1%) identified in a randomized grouping strategy. Furthermore, the intrapair trend of the differentially expressed proteins was not consistent and none of the proteins showed the same trend in more than 9 pairs of eyes.\n\nConclusions and clinical relevance: Unilateral relapse of BDU does not appear to cause asymmetric changes in the tear proteome between active and contralateral quiescent eyes. Tear fluid is a valuable source for biomarker studies of systemic diseases.\n\nStatement of clinical relevanceTears are an easily, noninvasively accessible body fluid that is a valuable source of biomarkers for various diseases. Behcets disease uveitis (BDU) has high potential to cause blindness and represents the leading cause of morbidity in BD patients, especially in frequently relapsing cases. Here, we adopted a method combining a \"dry\" method for tear preservation and nano-LC-DIA-MS/MS system to explore whether unilateral relapse of BDU causes differences in the tear proteome between the diseased and the contralateral quiescent eye, with the aim of evaluating tear fluid as a source for biomarker studies of uveitis relapse.