Glasses study shows huge productivity boost for workers

The PROSPER (PROductivity Study of Presbyopia in Rural-dwellers) trial of Indian tea pickers has found that provision of a £1.50 pair of reading glasses improved productivity by 22% over a three month period. The results were even more profound in the over-50 age group with a 32% increase in productivity. This represents the largest ever recorded productivity increase from any health intervention.

Orbis collaborated on the study, which was sponsored by Clearly, a global campaign to ‘help the whole world see’.

Involving 750 mostly female tea pickers on plantations in Assam, the ‘randomised controlled trial’ showed that the daily weight of tea picked by those given glasses increased by over five kilos, translating into increased income for the tea pickers and their families.

This increase in women’s earnings has a far-reaching impact; reducing poverty in the community and improving health and well-being for children. Over 95% of those taking part in the trial said they would recommend them to others, showing how valuable the glasses were found to be.

If the improvement was replicated across India’s crop industry it would mean an extra $20 billion in growth from productivity gains alone.

Commenting on the study, principal investigator Nathan Congdon, Orbis Director of Research said: “We thought it was crucial to demonstrate that performance, even of tasks which may not seem obviously visual, can be boosted so impressively by glasses.

"Nearly 90% of workers were still wearing their glasses by the end of the study and virtually all were willing to pay to replace them if needed– people knew they were benefiting from better vision.”

There are 253 million people in the world with visual impairment with the large majority (89%) of these living in low and middle income countries where access to eye care is scarce. Seven hundred years after glasses were invented, this study highlights the transformative effect they can have on global productivity and should encourage companies all over the world to ensure that their workers have access to glasses and other eye care treatments.