Dryness Response of the Ocular Surface With Use of Wearable Ventilation for Improving Air Quality and Comfort.

Background: Wearable ventilation paradigms have been increasingly proposed for various polluted workplaces due to its effectiveness in improving air quality and comfort but the impact of air movement on eye dryness has not been adequately addressed. Methods: This study investigated the subjective perceptions and objective ocular surface dryness responses of 12 participants in a wearable ventilation environment. Experiments were conducted under three thermal conditions: isothermal air supply at 26°C, isothermal air supply at 32°C, and cool air supply at 32°C. Results: The perceived air quality improved continuously with increasing air supply time. Thermal acceptability in hot environments was significantly enhanced after ventilation. Participants found the experimental air velocity range of 1.0-1.6 m/s and the associated eye dryness to be acceptable. However, objective measurements revealed that after air supply, blinking frequency increased by 25-60%, tear film break-up time decreased by 30-43%, and the ocular surface discomfort index increased. Ophthalmologists indicated these changes signify a health risk for dry eye syndrome. Conclusion: The results highlight potential health risks under current wearable ventilation environments and subjective assessments method for air movement acceptability. These findings have important implications for the design and implementation of wearable ventilation systems.