Objective: To evaluate the effects of video terminal protective lenses in relieving asthenopia of videooperators. Methods: This prospective clinical research included 60 video operators (age range: 26-45years) with asthenopia symptoms while working in the ultrasound department of our hospital. The subjectswere randomly assigned to two groups. The test group (n=30) wore video terminal protective lenses.The control group (n=30) wore ordinary aspherical lenses. After one hour of video operation, binocular vision-related testing and tear break up time (BUT) were measured in all subjects wearing the ordinary aspherical lenses, and an asthenopia questionnaire assessment was administered. After that, subjects in each group underwent contrast sensitivity (CS), and then they worked as usual, wearing their assigned lenses. Three months later, the subjects in each group underwent binocular vision-related testing, and BUT measurements. The asthenopia questionnaire assessment was again administered as well as the adverse reaction questionnaire. Data were analyzed by t-tests and chi-square tests. Results: After wearing videoterminal protective lenses, the CS with glare at low and medium-frequency grating (1.0 cpd, 1.7 cpd, 2.6 cpd) in the test group were significantly higher than in the control group under bright conditions (t=2.181,2.012, 2.088, all P<0.05). Under dark conditions, the CS of various frequencies in the test group also higher than in the control group (t=2.220, 2.558, both P<0.05) at low-frequency grating (1.0 cpd、1.7 cpd). The CS at low-frequency grating in the absence of glare in the test group was higher than in the control group
(bright: t=2.123, 2.530, both P<0.05; dark: t=2.433, 2.140, both P<0.05). In the test group, after wearing the video terminal protective lenses for three months, the amplitude of accommodation, accommodative sensitivity, and BUT were significantly elevated (t=-2.735, -3.281, -2.249, all P<0.05), while the near
point of convergence, near lateral exophoria, and the asthenopia gratings were significantly decreased (t=3.049, 1.369, 3.754, all P<0.05). However, in the control group, the amplitude of accommodation, near point of convergence, accommodative sensitivity, phorias, and BUT after 3 months were not significantly
altered compared with those before the experiment. Further, the asthenopia grating was not significantly decreased. Accommodative converse/Accommodation ratio in neither group was significantly altered compared with before the experiment. At 3 months, the constituent ratio of adverse reactions was not significantly different between the two groups. Conclusions: A 3-month follow-up revealed that compared with ordinary glasses, video terminal protective lenses increased the low- and medium-frequency CS under bright and dark conditions and improved binocular visual function and BUT. The improvements effectively relieved asthenopia and had no severe adverse reactions, suggesting the potential for clinical application.