Key Takeaways

  • Providing simple near-vision glasses to garment workers increased productivity by 6%, while reducing errors and improving output quality
  • The intervention is highly cost-effective, costing under $10 per worker and delivering a 337% return on investment over 3 months
  • Scaling vision correction across the global garment workforce could generate billions in additional output and significantly improve worker wellbeing

A new study published in the British Journal of Ophthalmology has found that providing simple reading glasses to garment factory workers significantly improves productivity, offering a low-cost solution with major economic implications for the global apparel industry.1

The randomized controlled trial, conducted in factories in India, revealed that correcting near vision among sewing machine operators increased productivity by 6%, while also reducing errors and improving output quality. Researchers found that 27% of workers suffered from poor near vision—commonly caused by age-related presbyopia—and did not own corrective glasses prior to the study.

The intervention, which provided free glasses to 344 workers at factories operated by Shahi Exports, India’s largest apparel manufacturer, demonstrated immediate benefits. Workers with corrected vision completed more garments and made fewer mistakes, highlighting the critical role of eyesight in precision-based manufacturing.

The findings suggest that scaling access to vision correction across the global garment workforce—particularly in South and Southeast Asia—could yield substantial economic benefits. Researchers estimate that equipping workers with glasses could enable the production of an additional 3.8 billion garments annually, adding approximately $27 billion in output to the global industry.

The program proved highly cost-effective, costing less than $10 per worker and delivering a return of $3.37 for every $1 invested over a 3-month period—a 337% return on investment. If sustained over a year, the return could rise to more than 1,600%, according to projections.

Following the study’s results, Shahi Exports announced plans to expand free vision screening to its entire workforce of approximately 100,000 employees. The move signals growing recognition within the industry of the link between worker wellbeing and operational performance.

“This research tells us that through a simple pair of eyeglasses we are investing both in the wellbeing of our workers and in the productivity of our business,” said Anant Ahuja, Director of ESG and Sustainability at Shahi Exports.

Global brands including VF Corporation, Deckers Brands, and Primark have also begun collaborating with nonprofit VisionSpring to provide glasses to workers in their supply chains, supported by funding from Warby Parker.

The study was implemented by VisionSpring and Good Business Lab, with academic leadership from Queen’s University Belfast, the University of Michigan, and the University of California San Diego. It forms part of the PROSPER II trial, under the DRIVE initiative, which explores how vision correction can support economic development.

While PROSPER II is the first randomized trial of its kind in a factory setting, it builds on earlier studies showing even larger productivity gains in other sectors. Previous research in India’s tea gardens found a 22% increase in output, while a study in Bangladesh reported a one-third rise in incomes among rural workers.

Reference

1. Pant S, Bagwe S, Esther S, et al. PROductivity Study of Presbyopia Elimination in gaRment workers (PROSPER II): a randomized trial on the productivity impact of providing near glasses to Indian garment factory workers. Br J Ophthalmol. Published online April 27, 2026. doi:10.1136/bjo-2025-328563.