A simple fix: could reading glasses boost factory output?
NCT ID NCT04629820
First seen Aug 20, 2026 · Last updated Aug 21, 2026 · Updated 1 time
Summary
This trial tests whether providing free reading glasses to textile workers aged 35 and older with presbyopia (age-related difficulty seeing close up) can improve their work productivity. Workers at a garment factory in India will be randomly assigned to receive glasses or not, and their efficiency, skill grade, and wages will be compared over three months. The goal is to see if correcting near vision can help older workers perform better and earn more.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- Reading glasses (near vision spectacles)
- What this could lead to
- If effective, providing free reading glasses to older workers with presbyopia could improve work productivity and wages, offering a simple, low-cost intervention for aging workforces.
- What could go wrong
- This is a single-industry trial in one factory, so results may not generalize. Adherence to wearing glasses and individual differences in productivity could affect outcomes.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
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Not a phased trial
Phase numbers describe drug development. The registry uses this when they do not apply, as it does for trials of devices, procedures or behaviour changes, and for observational studies.
- Participants
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682 people
The number who actually took part.
- Started
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Aug 2023
- Finished
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Dec 2024
- Lead sponsor
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Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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35 years and older
- Sex
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Anyone
- Healthy volunteers
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Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: * Aged 35 years and older * Have presbyopia, defined as an unaided near visual acuity of N6.3 or worse in both eyes * Require a new pair of glasses to improve their near vision * Have a corrected near visual acuity of N4 or better in both eyes * Have worked in Shahi's production department as tailors or Kajbutton operators for 6 weeks or more Exclusion Criteria: * Have ocular pathology in either eye detected during the eye examination, or history of such disease based on self-report * Have a low likelihood of completing follow-up in the study due to current plans to move out of the area or leave employment at Shahi during the follow-up period
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
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Good Business Lab
Bengaluru, Karnataka, 560102, India
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Other studies related to the condition(s) this trial covers.
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