Objective: To determine the amount of tear flow in a population aged between 20 and 30 and correlate it with the relative humidity in Arequipa and Lima (2019). Materials and methods: A quantitative, observational, descriptive and cross-sectional study conducted from July toAugust 2019. The study population consisted of patients aged between 20 and 30 attending ophthalmology clinics in Lima (79 people) and Arequipa (44 people). The exclusion criteria were the following: postoperative patients who underwent an eye surgery, contact lens wearers, people who used a computer over six consecutive hours a day, or those who were awake for less than two hours on the day of the test. Age, sex, place of residence, occupation, time of computer use, marital status, relative humidity and tear flow were assessed. An Excel database was analyzed using IBM SPSS Statistics statisticalsoftware with parametri...