
Prosper I
Completed in 2018
Country
India
Background issues
It had long been suspected that presbyopia, an age-related reduction in the ability of the eye to focus clearly at near distances, could significantly limit the productivity of adult workers reliant on near vision to perform tasks. However, before 2018, no randomised controlled trials had conclusively demonstrated the link between near vision and workplace productivity. Earlier studies lacked control groups, and the outcomes assessed were not precisely defined.
Trial design
PROSPER (PROductivity Study of Presbyopia Elimination in Rural-dwellers) was the first peer-reviewed randomised controlled trial to confirm a substantial increase in relative productivity—over 20%—among the intervention-group members in a rural cohort, primarily composed of female participants. The intervention was simple and widely accepted: low-cost near glasses for the correction of presbyopia. Completed in 2018, PROSPER I was an investigator-masked, randomised trial conducted in Assam, India, involving 751 consenting adults (predominantly women) who were randomly assigned to either the intervention group or control group. Participants in the intervention group received reading glasses at the start of the trial, while those in the control group were offered free glasses at the end of the trial if needed.
This peer-reviewed trial, which was the first of its kind, laid the groundwork for broader global advocacy. It not only provided a rigorous dataset but also served as the catalyst for global initiatives aimed at improving vision care. The credibility established by PROSPER contributed to the formation of the Friends of Vision group at the United Nations, with Ambassador Aubrey Webson of Antigua and Barbuda serving as the group’s sponsor and chair. The study’s impactful results were essential in building the momentum that culminated in a UN resolution advocating for vision care as a global priority.
Outcomes
The trial showed that adult presbyopic agricultural workers significantly benefited from eye examinations and vision correction. Workers aged 40–44 years who received glasses harvested 15·8% more than those without glasses. Similarly, workers aged 45–49 and 50 years or older saw increases of 18·9% and 31·6%, respectively, in their productivity. The data conclusively demonstrated that the productivity gains from correcting presbyopia increased with age.
PROSPER I also gained widespread attention beyond the academic community, with its findings being published in The Lancet, and further discussed in leading media outlets such as The Economist and the BBC news network. This recognition further solidified the trial’s influence, not just in the scientific community but also in international development and policy-making circles.
Timeline
The trial was completed within 3 months, with its rapid results making a significant impact on global vision care initiatives. The peer-reviewed findings were instrumental in advancing the case for vision correction as a cost-effective intervention to improve productivity and quality of life.
ClinicalTrials.gov Identifier: NCT03228199









