Refractive therapy is one of the most effective contemporaty methods of treatment and prophylaxis of the progression of myopia. Aim: to evaluate the influence of refractive therapy on tear break-up time (NITBUT) in patients aged 7-19 years during a period of 36 months. Method: Clinical prospective study, that included 80 eyes in patients aged 7-19 years with mild or moderate progressive myopia (mean -2,54±2,22 D). The treatment consisted of wearing night lenses for 6 to 8 hours during the night for 36 months. The NITBUT index was assessed before treatment, after 1, 7 and 14 days, 1, 3, 6, 12, 24 and 36 months of therapy. Results: In patients that applied night lenses over 36 months the NITBUT index remained practically unchanged during the study, the difference between the minimum and maximum values being statistically insignificant (p > 0.05): 9.52 ± 0.22 seconds before treatment and 9.92 ± 0.25 seconds after 36 months, respectively. Conclusion: Refractive therapy does not influence the tear break-up time in patients aged 7-19 years during a period of 36 months.