“…Most of these studies used only CS for tear collection [ 27 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ], one study used only SS [ 43 ], and four other studies used both tear collecting methods [ 44 , 45 , 46 , 47 ]. Our study confirms previous findings that CS samples had a higher SARS-CoV-2 detection rate compared to SS samples, and the viral loads in tear samples were lower compared to nasopharyngeal samples [ 44 , 45 , 46 , 47 ]. This is possibly because conjunctival scratching permits the collection of conjunctival cells, resulting in a larger volume of samples and, consequently, higher positivity rates.…”