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Impact of spectacles wear on uncorrected visual acuity among urban migrant primary school children in China: a cluster-randomised clinical trial
  1. Xinwu Zhang1,
  2. Ming Zhou1,
  3. Xiaochen Ma2,
  4. Hongmei Yi3,
  5. Haiqing Zhang4,
  6. Xiuqin Wang5,
  7. Ling Jin6,
  8. Kovin Naidoo7,8,9,
  9. Hasan Minto8,
  10. Haidong Zou10,
  11. Scott Rozelle11,
  12. Nathan Congdon6,12,
  13. Yue Ma11
  1. 1 School of Public Administration, Northwest University, Xi’an, China
  2. 2 China Center for Health Development Studies, Peking University, Beijing, China
  3. 3 Center for Chinese Agricultural Policy, Peking University, Beijing, China
  4. 4 College of Economics and Management, Shanghai Ocean University, Shanghai, China
  5. 5 Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
  6. 6 Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
  7. 7 African Vision Research Institute, University of Kwazulu-Natal, Durban, South Africa
  8. 8 Brien Holden Vision Institute, Sydney, Australia
  9. 9 School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
  10. 10 Shanghai Eye Disease Prevention and Treatment Center, Shanghai, China
  11. 11 Rural Education Action Program, Freeman Spogli Institute for International Studies, Stanford University, CA, USA
  12. 12 Centre for Public Health, School of Medicine, Dentistry, and Biomedical Sciences, Queen’s University Belfast, Belfast, UK
  1. Correspondence to Yue Ma, Rural Education Action Program, Freeman Spogli Institute for International Studies, Stanford University, Palo Alto, CA, USA; yma3{at}


Objective To estimate the effect of providing free spectacles on uncorrected visual acuity (VA) among urban migrant Chinese school children.

Design Exploratory analysis from a parallel cluster-randomised clinical trial.

Methods After baseline survey and VA screening, eligible children were randomised by school to receive one of the two interventions: free glasses and a teacher incentive (tablet computer if ≥80% of children given glasses were wearing them on un-announced examination) (treatment group) or glasses prescription and letter to parents (control group). The primary outcome was uncorrected logarithm of the minimal angle of resolution (LogMAR) VA at study closeout, adjusted for baseline uncorrected VA.

Results Among 4376 randomly selected children, 728 (16.6%, mean age 10.9 years, 51.0% boys) at 94 schools failed VA screening and met eligibility criteria. Of these, 358 children (49.2%) at 47 schools were randomised to treatment and 370 children (50.8%) at 47 schools to control. Among these, 679 children (93.3%) completed follow-up and underwent analysis. Spectacle wear in the treatment and control groups was 68.3% and 29.3% (p<0.001), respectively. Uncorrected final VA for eyes of treatment children was significantly better than control children, adjusting only for baseline VA (difference of 0.039 LogMAR units, 95% CI: 0.008, 0.070, equivalent to 0.39 lines, p=0.014) or baseline VA and other baseline factors (0.040 LogMAR units, 95% CI 0.007 to 0.074, equivalent to 0.40 lines, p=0.020).

Conclusion We found no evidence that spectacles wear worsens children’s uncorrected VA among urban migrant Chinese school children.

  • Field of vision
  • Public health
  • Clinical Trial
  • Vision
  • Epidemiology
  • Optics and Refraction

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  • Contributors Conceptualisation, YM and NC; Data curation, YM; formal analysis, XZ; investigation, YM; methodology, XM and HY; project administration, YM; supervision, MZ and SR; writing—original draft, XZ; writing—review & editing, YM, NC, HZ, XW, LJ, KN, HM and HZ; data analysis: XZ and YM.

  • Funding This research was funded by 111 Project (Grant No. B16031). The free spectacles used in this study were supplied by OneSight, Luxottica-China, producers of frames and lenses in China, who also provided financial support for the study. NC is supported by the Ulverscroft Foundation (UK).

  • Competing interests NC is Director of Research for Orbis International, a non-governmental organisation which delivers children’s refraction among other services in China and other countries.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement Data are available upon reasonable request.

  • Data integrity statement All the authors had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

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