About the Authors

Hannah Kuper

hannah.kuper@lshtm.ac.uk

Affiliation Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom

Sarah Polack

Affiliation Department of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom

Wanjiku Mathenge

Affiliation Department of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom

Cristina Eusebio

Affiliation Cataract Foundation of the Philippines, Bacolod, Negros Occidental, Philippines

Zakia Wadud

Affiliation Child Sight Foundation, Dhaka, Bangladesh

Mamunur Rashid

Affiliation CSS Rawm Hospital, Khulna, Bangladesh

Allen Foster

Affiliation Department of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom

Competing Interests

Professor Allen Foster is president of CBM, but other organisations were not involved in preparing the manuscript, the data collection, data analysis or the decision to publish. Professor Allen Foster was involved in this study in his position as Director of the International Centre for Eye Health at the London School of Hygiene & Tropical Medicine. At the time of the study Professor Foster was also the Medical Advisor to CBM. In January 2006, two years into the study, Professor Foster was appointed president of CBM. He contributed to the conception of the study question, study design and critically reviewed the draft of the article. He was not involved in the data collection, data analysis or interpretation of results. This does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: HK SP AF. Performed the experiments: HK, SP, CE, WM, MR, ZW. Analyzed the data: HK. Wrote the paper: HK. SP responsible for data management.