VDU work: longitudinal survey on refractive defects

A longitudinal survey in two different phases with an interval of 4 years (including more than 23,000 employees) has been carried out to study whether the time spent using VDU (daily hours and years of work) can change the refractive state. With reference to the whole sample including all refractions, there was no significant difference in the refractive state in employees who spent varying daily hours or years working at VDU. Furthermore, there were no significant changes in the refractive states of emmetropic, hypermetropic and myopic subjects, with regard to the time spent working at VDU. The data have shown that a high exposure to VDU work (more than 6 h per day or more than 6 years spent working at a VDU) is not responsible for inducing or worsening refractive error.