Abstract : Mitomycin C (MMC) is used to prevent corneal opacity following photorefractive keratectomy (PRK). The present research seeks to study the effect of Mitomycin C on tear film function tests among patients with low myopia. This study was a double blind randomized clinical trial conducted on 15 patients (30 eyes) with low myopia referred to AL Zahra Ophthalmology hospital, Zahedan, Iran in 2016. Patients with low myopia were randomized into two groups: The eyes of one group were treated using PRK while the eyes of the other group were exposed by both PRK and adjuvant MMC0.02%. Using T-test and Repeated Measurement ANOVA, the results of tear film tests were statistically analyzed and studied. The study enrolled 15 patients.30 eyes (15 patients) with a mean age of 27.53 ± 7.04 years were studied. Tear film function tests were conducted before and after PRK.Osmolaritytest was checked before operation and in the third month following operation. Other tests (Schirmer, TBUT) were performed before the operation and within the 1st, 3rd, and 6th months following the operation. The patients were not given any medicines 24 hours prior to the operation. No statistically significant differences were observed in tear osmolarity, TBUT and Schirmer test (P>0.05) between PRK and PRK+MMC before the operation and post-operation visits. Using MMC in PRK operations does not cause any disruptions in tear tests and MMC can be used safely if necessary