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Study Overview

Assessment of the Impact of Receiving Eyeglasses on Productivity in Handicraft Weaving in Rwanda
Study is 3ie funded:
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Last Update Date:
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Change History for Status
Changed On Previous Value
07/13/2018 Ongoing

Vision For a Nation (VFN) Foundation, working with the Rwandan Ministry of Health, aims to provide eyeglasses to all Rwandan adults who need them. The research proposed here assesses the impacts of eyeglasses provision on the productivity and income-generating capacity of Rwandan adults who work in one particular income-generating activity open to many Rwandans with low education: handicraft weaving. The research employs a randomized control trial design and the direct measurement of handicraft weaving productivity in a controlled setting. The randomized control trial design allows us to interpret any differences in productivity between treatment and control groups as unbiased estimates of the impacts of the treatment. To our knowledge, this research will provide the first rigorous estimate of the impact of vision correction on productivity in any developing country. The study will involve approximately 300 current and former members of handicraft weaving cooperatives. All participants will also receive free vision testing and, for those who need them, eyeglasses. The study will take place during the months of September through November 2013.

Registration Citation:

Glewwe, P. and Schaffner, J., 2013. Assessment of the Impact of Receiving Eyeglasses on Productivity in Handicraft Weaving in Rwanda. Registry for International Development for Impact Evaluations (RIDIE). Available at:

Health, Nutrition, and Population
Private Sector Development
Additional Keywords:
Vision, eyeglasses, worker productivity, handicraft weaving.
Secondary ID Number(s):

Principal Investigator(s)

Name of First PI:
Paul Glewwe
University of Minnesota
Name of Second PI:
Julie Schaffner
Tufts University

Study Sponsor

Vision For a Nation (VFN) Foundation
Study Sponsor Location:
United Kingdom

Research Partner

Name of Partner Institution:
Azizi Life
Type of Organization:
NGO (local) or other civil society organization

Intervention Overview


The intervention is the provision of eyeglasses to handicraft weavers in Rwanda. As these adults age, their eyes gradually become less able to see objects close at hand. They are provided reading glasses that allow them to see better the handicraft objects that they are working on. The ultimate objective is to increase their productivity (speed of production) and also the quality of the items they make. This is a small scale pilot project, and the expected beneficiaries are about 300 handicraft weavers.

Private Intervention Details:
Theory of Change:
Multiple Treatment Arms Evaluated?

Implementing Agency

Name of Organization:
Vision for a Nation Foundation
Type of Organization:
NGO (International)

Program Funder

Name of Organization:
Vision for a Nation Foundation
Type of Organization:
NGO (International)

Intervention Timing

Intervention or Program Started at time of Registration?
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Evaluation Method

Evaluation Method Overview

Primary (or First) Evaluation Method:
Randomized control trial
Other (not Listed) Method:
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Method Details

Details of Evaluation Approach:

Working with Azizi Life and one or two other non-governmental organizations that work with handicraft weaving cooperatives, and with the leaders of the local cooperatives, we will invite 6 groups, each with approximately 50 current and former handicraft weaving cooperative members, to participate in the study. Half of these groups will form our treatment sample, while the other half will serve as our control sample. Each group will be formed by inviting members of selected local cooperatives to participate. The groups of cooperatives will be stratified into pairs, with the two groups in each pair matched in ways that should render them as similar as possible. Within each pair we will randomly assign one group to the treatment sample and the other to the control sample. Immediately after gathering baseline productivity measurements for all members of treatment and control samples, we will administer vision testing to members of the treatment sample, and provide those who require vision correction with eyeglasses. Approximately three weeks after each group has participated in the baseline study, we will invite them to return for the follow-up productivity measurement.

Private Details of Evaluation Approach:
Outcomes (Endpoints):

1. Number of handicraft objects completed. 2. Quality of handicraft objects completed.

Unit of Analysis:
Individual handicraft weaver

1. Providing eyeglasses to current handicraft weavers increases their productivity. 2. Providing eyeglasses to current handicraft weavers increases the quality of the objects they make. 3. Providing eyeglasses to former handicraft weavers whose vision caused them to stop that work will be able to return to that work.

Unit of Intervention or Assignment:
Group of about 50 weavers
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Size of Treatment, Control, or Comparison Subsamples:
150 treatment, 150 control

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Outcomes Data

The data will be a survey of handicraft weavers who participate in the evaluation. Additional data will be collected by health workers on these weavers' vision.
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Treatment Assignment Data

Participation or Assignment Information:
Data Obtained by the Study Researchers?
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Data Analysis

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Study Materials

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Registration Category

Registration Category:
Prospective, Category 1: Data for measuring impacts have not been collected

Completion Overview

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Preliminary Report:
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Data Availability

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Other Materials

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Description of Changes:

Study Stopped


After the data were collected it was clear that the sample size was too small to get an accurate estimate of the impact of the intervention.