Objectives: To evaluate the effect of corneal subepithelial infiltrates (SEIs) on tear film function and best-corrected visual acuity (BCVA) after persistent epidemic keratoconjunctivitis (EKC) and to compare the findings with controls. Methods: In this prospective, cross-sectional study, 38 patients with EKC and 42 healthy volunteers were enrolled. While patients with SEIs after EKC made up groups 1a (first involved eye) and 1b (second involved eye), healthy controls made up group 2. Best-corrected visual acuity, corneal subepithelial infiltrate scoring (CSIS), Fantes score, tear breakup time (TBUT), Schirmer test, and ocular surface disease index (OSDI) scores were measured. The Oxford grading system was used to score corneal staining. Results: The mean Fantes score was 1.8 +/- 0.8 for group 1a and 1.3 +/- 1.1 for group 1b (P=0.03). The mean CSIS was 2.9 +/- 1.3 for group 1a and 1.9 +/- 1.7 for group 1b (P=0.005). But there was no significant difference in terms of the mean BCVA, TBUT, Schirmer, OSDI, and Oxford grading (P=0.66, 0.9, 0.9, 0.9, and 1.0, respectively) between group 1a and group 1b. The mean BCVA, TBUT, Schirmer, and OSDI values were worse in group 1a and group 1b in comparison to group 2 (P=0.001). Conclusions: We showed that the first involved eyes of patients with SEIs may be affected more significantly, but this difference may not have a clinical reflection on the difference in tear film functions between two eyes. However, compared with the healthy eyes, tear film function and BCVA were equally compromised in both eyes of the patients with SEIs irrelevant to the involved eye.