Does near-vision correction improve digital data entry accuracy? A simulated within-subject crossover study among community health workers in Malawi

Introduction Presbyopia, an age-related loss of near vision, affects approximately 80% of adults over 40 and 100% of adults over 60. Although correctable with inexpensive reading glasses, fewer than 20% of those affected in low- and middle-income countries have access to appropriate correction. Uncorrected presbyopia impairs daily functioning and productivity. The impact of presbyopia on health workforce performance remains unexplored, despite the impact of data accuracy on patient safety and the increasing reliance on mobile data entry and digital tools. This study assesses whether near-vision correction improves community health worker (CHW) data accuracy and entry speed. Methods We conducted a mixed-methods, within-subject crossover study among 400 CHWs in Dowa district, Malawi. Participants (n=105) with screened presbyopia completed two simulated data entry tasks in Dimagi’s CommCare mobile application, once with and once without reading glasses in random order. Task accuracy and completion time were assessed, adjusting for age and testing order. Post-task surveys explored perceptions of ease, accuracy and work impact. Results Wearing appropriate reading glasses nearly doubled the odds of accurate data entry (OR=1.92, 95% CI 1.71 to 2.16; p<0.001). No statistically significant effect was observed on task speed, although 84% of participants reported glasses made data entry easier and 81% perceived themselves as faster. Nearly all (93%) believed reading glasses could increase their impact and were willing to pay for them. Conclusion Providing low-cost reading glasses improved data entry accuracy among CHWs with presbyopia. As digital health systems expand, addressing uncorrected near-vision loss may reduce medical errors and improve care.