Blinking activity during visual display terminal work. Part 1: ocular discomfort and pathophysiological principles

Up to three-fourths of visual display operators complain about ocular discomfort after lengthy work at a monitor. The increase of displays at work has resulted in a problem area with growing impact for the economy and healthcare. Symptoms overlapping the complaints of dry eye disease point to the joint pathophysiological origin. In numerous studies the drastic decrease in blinking frequency was shown to be an essential cause of dry eye symptoms. Lid movements not only have the purpose of smoothing the precorneal tear film ("windshield effect"), but also affect the composition and stability of the different layers. Unfortunately, previous work has often been limited by the heterogeneity of measurement settings, leading to inconsistent results.