Impact of Air Movement on Eye Symptoms

The impact of direction, oscillation and temperature of isothermal room air movement on eye discomfort and tear film quality was studied. Twenty-four male subjects participated in the experiment. Horizontal air movement against the face and chest was generated by a large desk fan – LDF and a small desk fan (2.5 W) powered by laptop computer – USBF and upward movement by a personalized ventilation supplying air from desk front edge - PV. The exposed subject had control over the rotation speed of the fans as well as the personalized airflow rate and its direction to be against the chest, upward to the face or both. At room air temperature of 25 °C and relative humidity of 50 % the subjects were exposed for 30 min to three conditions - without elevated air movement and USBF with and without oscillation and to six conditions at 30 °C and 50 % RH – without elevated movement, USBF without oscillation when the airflow was directed against the face and when against the chest, LDF with and without oscillation and PV. Eye tear film samples were taken and analyzed at the beginning and the end of the exposures. Eye irritation and dryness were reported by the subjects. The air movement under individual control did not change significantly the tear film quality though tendency for improvement was observed. Eye dryness increased much when the airflow was blowing constantly against the face compared to oscillating airflow, airflow directed against the chest and upward airflow against the face.