The purpose of the study is to analyse the relationship between smoking and dry eye syndrome. The instrumentation consists of the Ocular Surface Disease Index (OSDI) questionnaire, based on 12 questions related to subjective ocular signs and symptoms that appeared during the different activities of daily life, qualitative tests like Schirmer I (without anesthesia) and for assessing the quality of tears the T-BUT and the tears pH was performed. In the study 75 subjects were included with ages between 20-45 years old, smokers and non-smokers, healthy persons with no medication, with no ophthalmic surgery in the last 6 months and not contact lens wearers. Results show the presence of dry eye symptoms more advanced in smokers compared to non-smokers