Computer-specific progressive addition lenses (PC-PALs) are shown to reduce computer vision syndrome (CVS) symptoms, increase visual comfort and tolerance, and improve body posture at the personal computer. They are highly preferred by computer workers. Increasing their use may aid prevention measures within the workplace health management.
This study investigates whether technical differences between general-purpose progressive addition lenses (GP-PALs) and PC-PALs are subjectively manifest in CVS.
MATERIALS AND METHODS
One hundred ninety presbyopic visual display unit (VDU) workers aged 53 ± 6 years (mean ± SD) were fitted with GP-PALs and PC-PALs in a subject-masked, randomized, crossover study. Subjects tested both corrections at their personal workplace for 2 weeks each, for VDU work only. Comfort and lens type preferences were assessed using a 24-item questionnaire developed for this study.
Computer vision syndrome was perceived approximately seven times more often with GP-PALs compared with PC-PALs. Eighty-four percent of subjects preferred PC-PALs for their VDU work. Computer-specific progressive addition lenses ratings were statistically and clinically significantly better than GP-PALs (5.95 vs. 4.42 of 7 points; 1.53; 95% confidence interval, 1.20 to 1.85). An existing ametropia or prior experience with PALs did not influence the score. Only 14.2% of subjects had received information about specific VDU eyewear from their optician or optometrist, whereas 79% expressed the wish to be informed about these products.
Computer-specific progressive addition lenses reduce the perception of the CVS and are highly preferred by VDU workers.