The relationship between lighting and visual eye fatigue and sleep quality in video display terminals users

The most complaints of Video Display Terminals (VDT) users are visual fatigue. Inadequate sleep quality is one of the factors that affect one's occupational performance. Since low sleep quality, visual fatigue and inappropriate lighting cause errors and reduce accuracy in work, so, the aim of this study was to determine the relationship between lighting and visual fatigue and the relationship between visual fatigues and sleep quality.
This descriptive cross-sectional study was conducted on 191 VDT users in various occupations in 2016 and Lux meter device was used to measure the lighting. Pittsburg sleep quality and visual fatigue questionnaires were used. The results were analyzed using SPSS software.
The average of eye fatigue score before and after work were 0.72±1.03 and 2.66±2. The mean intensity of lighting was 345.34±274.3 Lux and Sleep Quality Index score was 6.29±2.67. There was no significant correlation between lighting and difference of visual fatigue (P=0.552, r=-0.043). The relationship between eye fatigue and sleep quality score was significant (P The results of this study showed that visual fatigue and sleep quality have a reverse relationship. As visual fatigue increased in VDT users, the status of sleep quality became weaker, so that visual fatigue, along with complaints of pain, pressure, and blurred vision, increasing the number of errors during job tasks and thus disrupting the work. Therefore, in order to improve these problems, it is necessary to pay attention to the duration of sleep at night and the related parameters.