Refractive ErrorsSLIINCT06065631
Seeing to Learn in Sierra Leone
A study testing Eyeglasses and Prescription slip in people with Refractive Errors, run by University of Minnesota at 1 site in Sierra Leone.
Trial summary
The main objective of the Sierra Leone Sees to Learn (SL2) trial is to assess the educational impact of providing free eyeglasses to students aged 9-20 years with uncorrected refractive error in Sierra Leone. Read more about this study
- Who is it for?
- Ages 9 to 20 years
- Conditions the study is for
- Refractive Errors
- What is being tested?
- Eyeglasses and Prescription slip
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 1,821 participants
- Where
- 1 siteSierra Leone
- Study dates
- 25 Oct 2023to 31 Jan 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 9 to 20 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Presenting (with or without glasses) distance visual acuity of 6/12 or worse in the better-seeing eye;
- Refractive error of at least 0.75 diopters (D) of myopia, 2.00 D of hyperopia or 1.00 D of astigmatism;
- Visual acuity is correctable to 6/7.5 or better with eyeglasses.
Who cannot join
- 1. Other ocular problems preventing visual acuity > 6/12 in both eyes.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Seeing to Learn in Sierra Leone: Impact of Spectacle Correction on Children's Academic Performance and Mental Health Wellbeing
The main objective of the Sierra Leone Sees to Learn (SL2) trial is to assess the educational impact of providing free eyeglasses to students aged 9-20 years with uncorrected refractive error in Sierra Leone. The procedures include baseline questionnaires and educational assessments to collect data on students and schools, and then the provision of free eyeglasses to students who have uncorrected (or undercorrected) refractive error (URE). The questionnaires and student assessments will take 1-2 hours. The duration of the study timeframe is one school year. The end-line questionnaires and student assessments will be administered at the end of the school year.
Read the detailed description
Objective: The main objective of the Sierra Leone Sees to Learn (SL2) trial is to assess the educational impact of providing free eyeglasses to students aged 9-20 years with uncorrected refractive error in Sierra Leone.
Sample frame: Approximately 2400 children with uncorrected (or undercorrected) refractive error (URE) at 300 randomly-selected schools in Freetown and Bo City. A similar number of children from the same schools but without vision problems will also be included, at baseline only, to compare their basic demographic characteristics and daily activities to those of the children with URE. The sample size may vary depending on the percentage of children with URE obtained from screening a total of 40,000 children. All children with URE as specified in the enrolment criteria below will be part of the study.
Design: Cluster-randomized control trial (cluster RCT), with schools as clusters.
Randomization, interventions and balancing: All eligible children will be randomized by school to receive at the start of the school year either: free ready-made or custom eyeglasses (Intervention), or an eyeglasses prescription and letter to parents, with free eyeglasses at end-line (Control). The clusters (schools) will be stratified into groups based on the prevalence of refractive error and on the score on the baseline mathematics and reading exams. The division of the sample into schools in the two cities (Bo and Freetown) will be in the same proportion as the proportion of the number of public schools in those two cities.
Power calculations (reading and math exams): Setting power = 0.8, statistical precision = 0.05, intracluster correlation = 0.2 (from 2019 Sierra Leone grade 8 learning assessment), 80 treated schools, 80 control schools, 15 students/school with uncorrected error, yields the following minimal detectable effect (MDE) sizes as a function of correlation between baseline and end-line tests:
MDE Correlation of baseline and end-line tests 0.101 0.7 0.127 0.6 0.148 0.5
A nested focus-group study will explore children's, parents' and teachers' attitudes towards vision, student learning, and wearing of eyeglasses, in order to design a locally-tailored intervention to promote wearing of eyeglasses.
Regression Framework:
The investigators will estimate the effect of the program using a single difference cross-sectional ordinary least squares regression (OLS), and a difference-in-difference (DID) OLS regression that includes observations at both end-line and baseline. The investigators will report two types of effects: the intent-to-treat (ITT) effects and local average treatment effects (LATE), using treatment assignment as an instrumental variable for participation. Analysis will use the observed baseline characteristics as control variables and account for school-level variation through a fixed effect.
- Conditions
- Refractive Errors
- Being tested
- Eyeglasses, Prescription slip
- Keywords
- Myopia, Hyperopia, Spectacle correction, Educational outcomes
- Medical subject headings
- Refractive Errors, Myopia, Hyperopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
EyeglassesDevice
Also called Glasses, Spectacle
Children with uncorrected/under-corrected refractive error will be provided with either ready made or custom eyeglasses based on their magnitude and types of refractive errors.
Prescription slipOther
Children with uncorrected/under-corrected refractive error will be provided with an eyeglasses prescription and letter to parents, but all of them will get eyeglasses at the end of the trial
| Study group | Role | What they receive |
|---|---|---|
| Control | Other | An eyeglasses prescription and letter to parents, with free eyeglasses at endline. Receives: Other: Prescription slip |
| Intervention | Experimental | free ready-made or custom eyeglasses Receives: Device: Eyeglasses |
What is being measured
The primary outcome is the main question the study is designed to answer.
Foundational mathematic and literacy skills
Item Response Theory to estimate a student's ability on a continuous scale and subsequently standardize students' scores on a continuous scale with respect to the control-group distribution at baseline (mean zero, standard deviation of one). Lower scores will indicate lower performance, and higher scores will indicate higher performance. A -1 would indicate a student's performance is 1 standard deviation below the mean of the control-group performance distribution at baseline. A zero would mean the student performed like the mean student in the control group at baseline.
Measured: Month 1 and 9 months after glasses are provided
Anxiety
Measured using Generalized Anxiety Disorder 2-item (GAD-2) questionnaire, the highest score is 8 and the lowest score is 2. Higher scores indicated more severe anxiety disorders.
Measured: Month 1 and 9 months after glasses are provided
Prosocial
Measured using Strengths \& Difficulties Questionnaire with the prosocial score ranges from 0 to 10 and higher scores indicate more prosocial behaviour.
Measured: Month 1 and 9 months after glasses are provided
Social and emotional problems
Measured using Strengths \& Difficulties Questionnaire with the score ranges from 0 to 40. Higher scores indicate more social and emotional problems.
Measured: Month 1 and 9 months after glasses are provided
Secondary outcomes (6)
Teacher-observed wearing of eyeglasses of children
Proportion of children observed wear across all children at daily assessments
Measured: Month 1 to Month 9 after glasses are provided
Self-reported wearing of eyeglasses compliance
Proportion of children who reported to be wearing their eyeglasses 1. Not at all 2. Sometimes 3. Most of the time 4. All the time
Measured: Month 9 after glasses are provided
Enumerator-observed wearing of eyeglasses
Actual presence of spectacles on the child's face (rather than having glasses at school) at the time of an unannounced examination
Measured: At Months 3, 6 and 9 after glasses are provided
Cost-effectiveness 1
Total eyeglasses distribution cost (excluding study cost) per child receiving, and wearing, eyeglasses at endline
Measured: Through study completion, an average of 9 months
Cost-effectiveness 2
Total eyeglasses distribution cost (excluding study cost) per 0.1 standard deviation test score gain
Measured: Through study completion, an average of 9 months
School attendance
Attendance data will be collected from attendance registry at school. This will be expressed in percentage. Lowest attendance being 0%, highest being 100%.
Measured: Daily from Month 1 to Month 9
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Oct 2023
- Study start25 Oct 2023
- Primary completion31 Jan 2025
- Study completion31 Jan 2025
Why it stopped: USAID stopped funding the study in March of 2025 because USAID was dismantled and stopped funding all research programs.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (10)Papers the sponsor has linked to this study.
- Other trials for Refractive ErrorsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- All eligible children will be randomized by school to receive at the start of the school year either: free ready-made or custom eyeglasses (Intervention), or an eyeglasses prescription and letter to parents, with free eyeglasses at endline (Control). The clusters (schools) will be stratified into groups based on the prevalence of refractive error and on the score on the baseline mathematics and reading exams. The division of the sample into schools in the two cities (Bo and Freetown) will be in the same proportion as the proportion of the number of public schools in those two cities.
- Masking
- Double blind
- Who is masked
- Investigator, Outcomes assessor
- Enrolment
- 1,821 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Minnesota
- Sponsor type
- University, hospital or other
- Collaborators
- Innovations for Poverty Action, Peek Vision, Vision Action
- Responsible party
- Sponsor
- Investigators
- Nathan Congdon, MD, Principal investigator, Queen's University, Belfast
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06065631
- Sponsor's protocol ID
- Glewwe Transfer
- Acronym
- SLII
- Status last verified
- Jan 2026
- First submitted
- 21 Sep 2023
- Last updated
- 20 Jan 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Only deidentified data will be shared, on request.
Publications
GBD 2019 Blindness and Vision Impairment Collaborators; Vision Loss Expert Group of the Global Burden of Disease Study. Trends in prevalence of blindness and distance and near vision impairment over 30 years: an analysis for the Global Burden of Disease Study. Lancet Glob Health. 2021 Feb;9(2):e130-e143. doi: 10.1016/S2214-109X(20)30425-3. Epub 2020 Dec 1.
PubMed 33275950Burton MJ, Ramke J, Marques AP, Bourne RRA, Congdon N, Jones I, Ah Tong BAM, Arunga S, Bachani D, Bascaran C, Bastawrous A, Blanchet K, Braithwaite T, Buchan JC, Cairns J, Cama A, Chagunda M, Chuluunkhuu C, Cooper A, Crofts-Lawrence J, Dean WH, Denniston AK, Ehrlich JR, Emerson PM, Evans JR, Frick KD, Friedman DS, Furtado JM, Gichangi MM, Gichuhi S, Gilbert SS, Gurung R, Habtamu E, Holland P, Jonas JB, Keane PA, Keay L, Khanna RC, Khaw PT, Kuper H, Kyari F, Lansingh VC, Mactaggart I, Mafwiri MM, Mathenge W, McCormick I, Morjaria P, Mowatt L, Muirhead D, Murthy GVS, Mwangi N, Patel DB, Peto T, Qureshi BM, Salomao SR, Sarah V, Shilio BR, Solomon AW, Swenor BK, Taylor HR, Wang N, Webson A, West SK, Wong TY, Wormald R, Yasmin S, Yusufu M, Silva JC, Resnikoff S, Ravilla T, Gilbert CE, Foster A, Faal HB. The Lancet Global Health Commission on Global Eye Health: vision beyond 2020. Lancet Glob Health. 2021 Apr;9(4):e489-e551. doi: 10.1016/S2214-109X(20)30488-5. Epub 2021 Feb 16. No abstract available.
PubMed 33607016Dandona L, Dandona R. What is the global burden of visual impairment? BMC Med. 2006 Mar 16;4:6. doi: 10.1186/1741-7015-4-6.
PubMed 16539747Glewwe P, West KL, Lee J. The Impact of Providing Vision Screening and Free Eyeglasses on Academic Outcomes: Evidence from a Randomized Trial in Title I Elementary Schools in Florida. J Policy Anal Manage. 2018;37(2):265-300. doi: 10.1002/pam.22043.
PubMed 29693366Keil S, Fielder A, Sargent J. Management of children and young people with vision impairment: diagnosis, developmental challenges and outcomes. Arch Dis Child. 2017 Jun;102(6):566-571. doi: 10.1136/archdischild-2016-311775. Epub 2016 Nov 16.
PubMed 27852581Ma X, Zhou Z, Yi H, Pang X, Shi Y, Chen Q, Meltzer ME, le Cessie S, He M, Rozelle S, Liu Y, Congdon N. Effect of providing free glasses on children's educational outcomes in China: cluster randomized controlled trial. BMJ. 2014 Sep 23;349:g5740. doi: 10.1136/bmj.g5740.
PubMed 25249453Naidoo KS, Raghunandan A, Mashige KP, Govender P, Holden BA, Pokharel GP, Ellwein LB. Refractive error and visual impairment in African children in South Africa. Invest Ophthalmol Vis Sci. 2003 Sep;44(9):3764-70. doi: 10.1167/iovs.03-0283.
PubMed 12939289Ma Y, Congdon N, Shi Y, Hogg R, Medina A, Boswell M, Rozelle S, Iyer M. Effect of a Local Vision Care Center on Eyeglasses Use and School Performance in Rural China: A Cluster Randomized Clinical Trial. JAMA Ophthalmol. 2018 Jul 1;136(7):731-737. doi: 10.1001/jamaophthalmol.2018.1329.
PubMed 29801081Wang X, Yi H, Lu L, Zhang L, Ma X, Jin L, Zhang H, Naidoo KS, Minto H, Zou H, Rozelle S, Congdon N. Population Prevalence of Need for Spectacles and Spectacle Ownership Among Urban Migrant Children in Eastern China. JAMA Ophthalmol. 2015 Dec;133(12):1399-406. doi: 10.1001/jamaophthalmol.2015.3513.
PubMed 26426113Williams WR, Latif AH, Hannington L, Watkins DR. Hyperopia and educational attainment in a primary school cohort. Arch Dis Child. 2005 Feb;90(2):150-3. doi: 10.1136/adc.2003.046755.
PubMed 15665167
Study at a glance
From the registry record, last updated by the sponsor on 20 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Seeing to Learn in Sierra Leone: Impact of Spectacle Correction on Children's Academic Performance and Mental Health Wellbeing
- ClinicalTrials.gov ID
- NCT06065631
- Acronym / sponsor ID
- SLII / Glewwe Transfer
- Conditions
- Refractive Errors
- Keywords
- Myopia, Hyperopia, Spectacle correction, Educational outcomes
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: USAID stopped funding the study in March of 2025 because USAID was dismantled and stopped funding all research programs.
- Enrolment
- 1,821 participants (actual)
- Lead sponsor
- University of MinnesotaUniversity, hospital or other
- Collaborators
- Innovations for Poverty Action, Peek Vision, Vision Action
- Study start
- 25 Oct 2023 (actual)
- Primary completion
- 31 Jan 2025 (actual)
- Study completion
- 31 Jan 2025 (actual)
- First posted
- 4 Oct 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The main objective of the Sierra Leone Sees to Learn (SL2) trial is to assess the educational impact of providing free eyeglasses to students aged 9-20 years with uncorrected refractive error in Sierra Leone. The procedures include baseline questionnaires and educational assessments to collect data on students and schools, and then the provision of free eyeglasses to students who have uncorrected (or undercorrected) refractive error (URE). The questionnaires and student assessments will take 1-2 hours. The duration of the study timeframe is one school year. The end-line questionnaires and student assessments will be administered at the end of the school year.
Detailed description
Objective: The main objective of the Sierra Leone Sees to Learn (SL2) trial is to assess the educational impact of providing free eyeglasses to students aged 9-20 years with uncorrected refractive error in Sierra Leone.
Sample frame: Approximately 2400 children with uncorrected (or undercorrected) refractive error (URE) at 300 randomly-selected schools in Freetown and Bo City. A similar number of children from the same schools but without vision problems will also be included, at baseline only, to compare their basic demographic characteristics and daily activities to those of the children with URE. The sample size may vary depending on the percentage of children with URE obtained from screening a total of 40,000 children. All children with URE as specified in the enrolment criteria below will be part of the study.
Design: Cluster-randomized control trial (cluster RCT), with schools as clusters.
Randomization, interventions and balancing: All eligible children will be randomized by school to receive at the start of the school year either: free ready-made or custom eyeglasses (Intervention), or an eyeglasses prescription and letter to parents, with free eyeglasses at end-line (Control). The clusters (schools) will be stratified into groups based on the prevalence of refractive error and on the score on the baseline mathematics and reading exams. The division of the sample into schools in the two cities (Bo and Freetown) will be in the same proportion as the proportion of the number of public schools in those two cities.
Power calculations (reading and math exams): Setting power = 0.8, statistical precision = 0.05, intracluster correlation = 0.2 (from 2019 Sierra Leone grade 8 learning assessment), 80 treated schools, 80 control schools, 15 students/school with uncorrected error, yields the following minimal detectable effect (MDE) sizes as a function of correlation between baseline and end-line tests:
MDE Correlation of baseline and end-line tests 0.101 0.7 0.127 0.6 0.148 0.5
A nested focus-group study will explore children's, parents' and teachers' attitudes towards vision, student learning, and wearing of eyeglasses, in order to design a locally-tailored intervention to promote wearing of eyeglasses.
Regression Framework:
The investigators will estimate the effect of the program using a single difference cross-sectional ordinary least squares regression (OLS), and a difference-in-difference (DID) OLS regression that includes observations at both end-line and baseline. The investigators will report two types of effects: the intent-to-treat (ITT) effects and local average treatment effects (LATE), using treatment assignment as an instrumental variable for participation. Analysis will use the observed baseline characteristics as control variables and account for school-level variation through a fixed effect.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- All eligible children will be randomized by school to receive at the start of the school year either: free ready-made or custom eyeglasses (Intervention), or an eyeglasses prescription and letter to parents, with free eyeglasses at endline (Control). The clusters (schools) will be stratified into groups based on the prevalence of refractive error and on the score on the baseline mathematics and reading exams. The division of the sample into schools in the two cities (Bo and Freetown) will be in the same proportion as the proportion of the number of public schools in those two cities.
| Arm | Type | Receives |
|---|---|---|
| Control | Other | Other: Prescription slipAn eyeglasses prescription and letter to parents, with free eyeglasses at endline. |
| Intervention | Experimental | Device: Eyeglassesfree ready-made or custom eyeglasses |
Who may qualify
- Ages
- 9 to 20 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (3 listed)
- Presenting (with or without glasses) distance visual acuity of 6/12 or worse in the better-seeing eye;
- Refractive error of at least 0.75 diopters (D) of myopia, 2.00 D of hyperopia or 1.00 D of astigmatism;
- Visual acuity is correctable to 6/7.5 or better with eyeglasses.
Key exclusion criteria (1 listed)
- 1. Other ocular problems preventing visual acuity > 6/12 in both eyes.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| EyeglassesAlso: Glasses, SpectacleChildren with uncorrected/under-corrected refractive error will be provided with either ready made or custom eyeglasses based on their magnitude and types of refractive errors. | Device | Intervention |
| Prescription slipChildren with uncorrected/under-corrected refractive error will be provided with an eyeglasses prescription and letter to parents, but all of them will get eyeglasses at the end of the trial | Other | Control |
Primary outcome
Foundational mathematic and literacy skills
Time frame: Month 1 and 9 months after glasses are provided
Item Response Theory to estimate a student's ability on a continuous scale and subsequently standardize students' scores on a continuous scale with respect to the control-group distribution at baseline (mean zero, standard deviation of one). Lower scores will indicate lower performance, and higher scores will indicate higher performance. A -1 would indicate a student's performance is 1 standard deviation below the mean of the control-group performance distribution at baseline. A zero would mean the student performed like the mean student in the control group at baseline.
Anxiety
Time frame: Month 1 and 9 months after glasses are provided
Measured using Generalized Anxiety Disorder 2-item (GAD-2) questionnaire, the highest score is 8 and the lowest score is 2. Higher scores indicated more severe anxiety disorders.
Prosocial
Time frame: Month 1 and 9 months after glasses are provided
Measured using Strengths \& Difficulties Questionnaire with the prosocial score ranges from 0 to 10 and higher scores indicate more prosocial behaviour.
Social and emotional problems
Time frame: Month 1 and 9 months after glasses are provided
Measured using Strengths \& Difficulties Questionnaire with the score ranges from 0 to 40. Higher scores indicate more social and emotional problems.
6 secondary outcomes
Teacher-observed wearing of eyeglasses of children
Time frame: Month 1 to Month 9 after glasses are provided
Self-reported wearing of eyeglasses compliance
Time frame: Month 9 after glasses are provided
Enumerator-observed wearing of eyeglasses
Time frame: At Months 3, 6 and 9 after glasses are provided
Cost-effectiveness 1
Time frame: Through study completion, an average of 9 months
Cost-effectiveness 2
Time frame: Through study completion, an average of 9 months
School attendance
Time frame: Daily from Month 1 to Month 9
Results and safety
The study was stopped early (reason given: USAID stopped funding the study in March of 2025 because USAID was dismantled and stopped funding all research programs.). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Jan 2026.
- Results publication: PubMed 33275950GBD 2019 Blindness and Vision Impairment Collaborators; Vision Loss Expert Group of the Global Burden of Disease Study. Trends in prevalence of blindness and distance and near vision impairment over 30 years: an analysis for the Global Burden of Disease Study. Lancet Glob Health. 2021 Feb;9(2):e130-e143. doi: 10.1016/S2214-109X(20)30425-3. Epub 2020 Dec 1.
- Results publication: PubMed 33607016Burton MJ, Ramke J, Marques AP, Bourne RRA, Congdon N, Jones I, Ah Tong BAM, Arunga S, Bachani D, Bascaran C, Bastawrous A, Blanchet K, Braithwaite T, Buchan JC, Cairns J, Cama A, Chagunda M, Chuluunkhuu C, Cooper A, Crofts-Lawrence J, Dean WH, Denniston AK, Ehrlich JR, Emerson PM, Evans JR, Frick KD, Friedman DS, Furtado JM, Gichangi MM, Gichuhi S, Gilbert SS, Gurung R, Habtamu E, Holland P, Jonas JB, Keane PA, Keay L, Khanna RC, Khaw PT, Kuper H, Kyari F, Lansingh VC, Mactaggart I, Mafwiri MM, Mathenge W, McCormick I, Morjaria P, Mowatt L, Muirhead D, Murthy GVS, Mwangi N, Patel DB, Peto T, Qureshi BM, Salomao SR, Sarah V, Shilio BR, Solomon AW, Swenor BK, Taylor HR, Wang N, Webson A, West SK, Wong TY, Wormald R, Yasmin S, Yusufu M, Silva JC, Resnikoff S, Ravilla T, Gilbert CE, Foster A, Faal HB. The Lancet Global Health Commission on Global Eye Health: vision beyond 2020. Lancet Glob Health. 2021 Apr;9(4):e489-e551. doi: 10.1016/S2214-109X(20)30488-5. Epub 2021 Feb 16. No abstract available.
- Results publication: PubMed 16539747Dandona L, Dandona R. What is the global burden of visual impairment? BMC Med. 2006 Mar 16;4:6. doi: 10.1186/1741-7015-4-6.
- Results publication: PubMed 29693366Glewwe P, West KL, Lee J. The Impact of Providing Vision Screening and Free Eyeglasses on Academic Outcomes: Evidence from a Randomized Trial in Title I Elementary Schools in Florida. J Policy Anal Manage. 2018;37(2):265-300. doi: 10.1002/pam.22043.
- Results publication: PubMed 27852581Keil S, Fielder A, Sargent J. Management of children and young people with vision impairment: diagnosis, developmental challenges and outcomes. Arch Dis Child. 2017 Jun;102(6):566-571. doi: 10.1136/archdischild-2016-311775. Epub 2016 Nov 16.
- Results publication: PubMed 25249453Ma X, Zhou Z, Yi H, Pang X, Shi Y, Chen Q, Meltzer ME, le Cessie S, He M, Rozelle S, Liu Y, Congdon N. Effect of providing free glasses on children's educational outcomes in China: cluster randomized controlled trial. BMJ. 2014 Sep 23;349:g5740. doi: 10.1136/bmj.g5740.
- Results publication: PubMed 12939289Naidoo KS, Raghunandan A, Mashige KP, Govender P, Holden BA, Pokharel GP, Ellwein LB. Refractive error and visual impairment in African children in South Africa. Invest Ophthalmol Vis Sci. 2003 Sep;44(9):3764-70. doi: 10.1167/iovs.03-0283.
- Results publication: PubMed 29801081Ma Y, Congdon N, Shi Y, Hogg R, Medina A, Boswell M, Rozelle S, Iyer M. Effect of a Local Vision Care Center on Eyeglasses Use and School Performance in Rural China: A Cluster Randomized Clinical Trial. JAMA Ophthalmol. 2018 Jul 1;136(7):731-737. doi: 10.1001/jamaophthalmol.2018.1329.
- Results publication: PubMed 26426113Wang X, Yi H, Lu L, Zhang L, Ma X, Jin L, Zhang H, Naidoo KS, Minto H, Zou H, Rozelle S, Congdon N. Population Prevalence of Need for Spectacles and Spectacle Ownership Among Urban Migrant Children in Eastern China. JAMA Ophthalmol. 2015 Dec;133(12):1399-406. doi: 10.1001/jamaophthalmol.2015.3513.
- Results publication: PubMed 15665167Williams WR, Latif AH, Hannington L, Watkins DR. Hyperopia and educational attainment in a primary school cohort. Arch Dis Child. 2005 Feb;90(2):150-3. doi: 10.1136/adc.2003.046755.
- Individual participant dataSharing planned: Yes. Only deidentified data will be shared, on request.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Nathan Congdon, MD principal investigator
Queen's University, Belfast
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Eyeglasses and Prescription slip in people with Refractive Errors, run by University of Minnesota at 1 site in Sierra Leone.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 20 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Sierra Leone. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was stopped early (reason given: USAID stopped funding the study in March of 2025 because USAID was dismantled and stopped funding all research programs.). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Foundational mathematic and literacy skills (time frame: Month 1 and 9 months after glasses are provided). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06065631, which also lists 10 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Jan 2026.