Int Arch Occup Environ Health ( 1988) 60:81-87 International Archivesof OCC Upano Iand- Enifronmental Health © Springer-Verlag 1988 Visual fatigue in video display terminal operators: objective measure and relation to environmental conditions F M Gobba l , A Broglia 2 , R Sarti 3 , F Luberto l , and A Cavalleril L Cattedra di Medicina del Lavoro, University of Modena, 1-41100 Modena 2 Istituto di Clinica Oculistica, University of Pavia, 1-41100 Pavia 3 Centro di Prevenzione Primaria, Milano, Fondazione Clinica del Lavoro, I-41100 Pavia, Italy Summary The lighting conditions, luminance, contrast, and design of the workplace were studied in video display terminal (VDT) work stations operated by a group of female VDT data-acquisition clerks. VDT-induced symptoms were assessed by means of subject answers to a questionnaire To measure VDT- induced ocular fatigue objectively, refraction power was determined before and at the end of workshift by an infrared autorefractometer Job-induced refrac- tion changes were then related to visual complaints and conditions in the workplace The results con- firmed that VDT data-acquisition work can lead to temporary myopia (myopization) in a remarkable percentage of operators; a significant correlation be- tween eye discomfort, ocular asthenopia, and myopi- zation was also found Illumination levels, lumi- nance, and contrast seem to be of paramount impor- tance regarding visual symptoms: neither asthenopia nor myopization was observed when all of these con- ditions were adequate If the ergonomic design of the workplace and the viewing distance are adequate, there are also usually fewer musculoskeletal symp- toms Our results suggest that changes in the ocular refraction status before and at the end of the work- shift, as determined by an automatic refractometer, provide a good objective index of VDT-induced "ocular fatigue", which in our study proved to be sig- nificantly related to workplace conditions. Key words: Video display terminals Asthenopia - Objective measurement Temporary myopia - Workplace conditions Offprint requests to: F M Gobba at the above address Introduction In recent years much has been written about adverse health effects on operators of video display terminals (VDT) l 3, 23, 26 l Many surveys suggest that VDT users frequently complain of symptoms of job-related ocular discomfort, musculoskeletal discomfort, and stress l 3, 12, 13, 26, 29 l, but unfortunately the work situations, study designs, and definitions of the symp- toms themselves differ considerably among the studies, and the incidences reported also vary greatly, which makes comparison difficult or unreli- able l 3 l. Methods for an objective evaluation of visual complaints are lacking: temporary changes in oculo- motor functions following VDT work have been re- ported l 3, 4, 14, 25, 27 l but not confirmed in other studies l 7, 8 l; furthermore, little is known about the relationship between these changes, ocular discom- fort, or environmental conditions l 26 l Finally, many surveys do not adequately examine the heterogeneity of the VDT job situation and the workplace aspects (e.g , lighting, reflections, work station design) re- garding the appearance of complaints l 26 l. In the present study we examined a group of 38 female VDT workers who were employed in data-ac- quisition tasks in a big enterprise The adequacy of the lighting conditions, luminance, contrast, and the work-station design were studied Job-related subjec- tive symptoms were assessed by questionnaire. Information on condition of the eyes was ob- tained by ophthalmological examination, and objec- tive refraction power before and at the end of the work shift was determined by an autorefractometer.