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New research reveals glasses boost worker productivity

Published: 25.07.2018

New research reveals glasses boost worker productivity. Tea-pickers; photo by Sarah Day for Clearly

As the first Global Disability Summit takes place, new evidence of how a simple pair of glasses can improve workers’ productivity and reduce poverty is published.

A trial of Indian tea pickers, has shown that the provision of glasses improved their productivity by 21.7 per cent – and for those aged over 50 the increase was 31.6 per cent. This represents the largest ever recorded productivity increase from any health intervention.

If the improvement was replicated across India’s crop industry it would mean an extra $19 billion in growth from productivity gains alone.

With over a billion worldwide suffering from poor vision and no access to glasses, the research demonstrates the crucial role of glasses in achieving the Sustainable Development Goals.

The findings – in a study called PROSPER [PROductivity Study of Presbyopia Elimination in Rural-dwellers] published in the Lancet Global Health  – will intensify the pressure on companies all over the world to ensure that their workers have access to glasses, which can cost as little as $1.50 to produce, and other eyecare treatments. It will also add to the growing clamour for large companies who operate in poorer countries to provide free work-based sight tests, meaning the findings could have a game-changing impact on the way companies prepare their staff for work.

Prosper is the first ever randomised controlled trial to explore the link between clear vision and productivity, representing a significant step forward in our understanding of the role of clear vision in accelerating the Sustainable Development Goals. The trial, which involved 750 mainly female workers on plantations in Assam, showed that the daily weight of tea picked by those given glasses increased by over 5 kilos, which translated directly into increased income for the tea-pickers and their families.

The research was sponsored by Clearly, a global campaign to bring clear vision to the people worldwide denied it as quickly as possible. It was carried out in collaboration with VisionSpring, a social enterprise dedicated to providing affordable glasses across the world, and Orbis, a global organization fighting avoidable blindness worldwide.

James Chen, founder of Clearly, said: ‘700 years after glasses were first invented we now have conclusive proof of the link between clear vision and productivity. Poor vision is the scandal the world forgot and affects a third of the world’s population. Solving this issue will accelerate progress against the UN’s goals on health, quality education, decent work, gender equality and poverty elimination.’

Ella Gudwin, President of VisionSpring, shared: “We now know definitively that a simple pair of reading glasses transforms workers’ productivity, not just in offices but in agriculture. This has profound implications. It means there is a cost effective and easy way to boost both household income and business performance in lower income communities. While the study focused on tea estates, we see broad applicability across a wide range of labor intensive workplaces.”

A spokesperson from Amalgamated Plantations Private Ltd, owners of the tea garden where the trial took place said: “There is a clear and certain case for improving vision and providing sight tests for our business’ employees. It makes work more productive and more rewarding, and at the heart of this study there is a clear message for businesses like ours – good vision is vital to what we do. This is a turning point in awareness of the impact of clear vision on our tea garden’s wellbeing and productivity. We are happy to have played a leadership role in this study and, along with Clearly, VisionSpring and Orbis, will fully support the policy recommendations that emerge as a result.”

Professor Nathan Congdon of Queens University Belfast and Director of Research at Orbis International, the study’s principal investigator 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 benefitting from better vision.’

Through its Clear Vision Workplace programme, VisionSpring enables businesses to ensure their workers, quality control teams, and managers see clearly, and helps companies achieve their worker well-being objectives. This year alone VisionSpring will screen the vision of 60,000 people working in agriculture, apparel and home goods, and provide them with the glasses they need. Through public-private partnerships, millions of workers around the world could see well and do well.

Clearly will write to leading businesses sharing the results of the trial and urging them to introduce work-based sight schemes.

Access the study here

About PROSPER (PROductivity Study of Presbyopia Elimination in Rural dwellers):

The PROSPER trial, is the first randomized controlled trial to show a link between good sight and work performance. It has shown for the first time that providing a simple pair of reading glasses, can very significantly improve productivity of rural agricultural workers. The trial was carried out over a period of three months in tea-plantations in Assam, India, with reading glasses given to 750 mostly-female Indian tea pickers, aged between 40 – 50 +years. The daily weight of tea picked increased by 5.25 kilogrammes a day (21.7%) overall when compared to controls over a three-month period, with the largest increase seen in those over 50, with an increase of 31.6 %. The effect on productivity is larger than any other health intervention reported in the scientific literature trials for low and middle-income countries. 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—a sure sign of how much the glasses were valued. Presbyopia, the gradual decline of near vision, is a nearly-universal part of aging. It affects over a billion people worldwide, making it the most common cause of vision impairment globally.