Foam formation in the eye canthus is well-known. The presence of foam was observed in 169 office workers in 4 town halls in Copenhagen County compared with 112 control persons from the general population in the same area. The presence of foam depends on age and gender. A significant increase with age was observed in the control population (P = 0.0078). In both groups, females had a significantly lower occurrence of foam than males (P = 0.0043, P = 0.010). This difference was mainly caused by the use of eye make-up. After correction for age, gender and use of eye make-up, the prevalence of foam was significantly lower in the office population than in the control population (P less than 0.0001). Furthermore, low foam formation was significantly correlated to reported subjective eye irritation in the office population (P = 0.0074), but not in the control population (P = 0.40). Also, significant positive correlation between absence of foam and different degrees of dry eyes (expressed as a combination of premature break-up of the precorneal tearfilm and lissamine green stained epithelial damage of the bulbar conjunctiva) was found both in the office population and in the control population (P = 0.0090, P = 0.0034). However, after correction for the more frequent appearance of dry eyes in the office population, foam was still observed significantly less frequently in the office population than in the control population (P = 0.0001). It is concluded that the decreased foam formation in the office worker constitutes a key symptom in the development of 'office eye syndrome'. In what way the office environment influences the foam formation is unknown. Possible mechanisms are discussed.