Aim: The aim of this study is to compare the quality of the tear film in three groups of patients, two of whom use eye drops in therapy that contain the preservatives benzalkonium chloride and polyquad and one that uses preservative-free drops in their therapy. Study structure: Prospective cohort research. Examination and methods: The study included 60 subjects of both sexes operated on due to cataract via phacoemulsification surgery. To assess tear film quality, each patient underwent a Schirmer test 1, a fluorescein test, and a tear-break-up-time test (TBUT) on the day of the surgery, on the 1st and 7th day after the surgery and one month after the surgery. The difference in the measured tear film before and after the phacoemulsification surgery was examined. All patients underwent surgery on INFINITY device (“Alcon” 2008) and got an intraocular lens implanted. Results: In all three groups of subjects TBUT values were significantly lower (P = 0.001) on the first day after surgery. On the day of surgery, there were significantly higher values of the fluorescein test (P = 0.005) in the group of subjects who had benzalkonium chloride in their therapy. Before and after surgery, the values of the TBUT test were significantly lower (P = 0.001) in the group of subjects who had benzalkonium chloride in their therapy. Conclusion: After cataract surgery via phacoemulsification, the quality of the ocular surface was reduced in all three groups of subjects. In the group of subjects who had the preservative benzalkonium chloride in therapy, the lowest quality of the ocular surface was observed. The best quality of the ocular surface was observed in the group of subjects who did not have a preservative in therapy.