Discomfort eye syndrome (DES) comprises a series of 'minor' subjective symptoms in patients where no relevant clinical signs are observed suggesting ocular disease. Our study includes 100 DES patients, excluding video terminal users, selected from the First Aid Service of our Department over two peak periods in both winter and summer time. The Schirmer test I, ferning test, breakup time and conjunctival cytology (scraping and imprint) were performed and data were related to sex, age and air pollution indexes, recorded in the patients' living zones. Our results demonstrate that: (i) the ocular surface cytology and the analysis of tear film changes provide significant information in those patients where no other clinical signs are evident; (ii) DES symptoms are more frequent in women than in men (ratio about 2:1), both with ages over 51 years; (iii) DES is significantly associated with ocular surface inflammation, as detected by cytological methods, and (iv) ocular surface subclinical inflammation and ocular dryness are related to high concentrations of atmospheric polluters, in both sexes.