Near vision correction and work productivity among textile workers

Abstract

Purpose: Uncorrected presbyopia (near vision impairment) is prevalent in approximately 517 million people worldwide; this prevalence ranges from 30% to 80% in Africa. Good near vision is needed for a range of tasks; therefore, uncorrected presbyopia can negatively affect the quality of life of individuals, impact families and society, and potentially have negative implications on employment and labour work productivity. This study aimed to determine the impact of near vision correction on the work productivity of clothing factory workers.

Methods: We conducted a cross-sectional study and sampled all workers who were aged 40 years and older and who performed near vision tasks (e.g. machinist, cutter, zip sewer, clothing pressers and quality controllers) in seven clothing factories. We included workers who were employed for at least 3 months and whose uncorrected near visual acuity could be improved and corrected to better than 6/9 with spectacle correction. Workers were provided with near vision spectacles, and changes in their work productivity were evaluated after 6 months, using the factories’ output records as an indicator for measurement.

Results: The final sample comprised 268 individuals, with 56% of African origin (n = 151) and 49% (n = 115) Indian origin. There were mainly females (94%) in the sample, and the average age was 48 years (± 5.5 years, range 40–62 years). The overall post-correction mean production score (70.5 [SD ± 19.9]) was significantly higher than the overall pre-correction mean production score (67.0 [SD ±20.3]) (p < 0.001). The average change in production score was 3.5 (95% confidence interval [CI] 2.7–4.3), and the percent difference was 6.4% (95% CI 5.2–7.7). The increase in work productivity was significant for individuals of African (p < 0.001) and Indian origins (p < 0.001) but not for those of mixed race (p = 0.364; n = 2). Post-correction, the production scores of women increased significantly by 6.6% (95% CI 5.3–7.9) (p < 0.001). Significant increases in production scores were recorded for machinists, clothing pressers and quality controllers.

Conclusion: Significant changes in work productivity among the workers with presbyopic correction were recorded. The clothing industry served as a favourable setting to examine changes in work productivity, obtaining reliable scores of output. This study was used as an exploratory investigation, and the results will be used to inform a randomised-controlled study that will provide stronger validation for the hypothesis that near vision correction impacts work productivity