1. International Centre for Eye Health, Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
2. Department of Biomedical Engineering, University of Strathclyde, Glasgow, United Kingdom
3. National Institute for Health Research, Biomedical Research Centre, University College London Institute of Ophthalmology, Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom
4. Glasgow Centre for Ophthalmic Research, National Health Service Greater Glasgow and Clyde, Gartnavel General Hospital, Glasgow, United Kingdom
5. International Centre for Eye Health, Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom5Medical Research Council Tropical Epidemiology Group, Faculty of Epid
6. Division of Optometry and Visual Science, School of Health Science, City University London, London, United Kingdom
7. International Centre for Eye Health, Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom7Kitale and Zonal Eye Surgery, Kitale Hospital, North Rift, Kenya Nort
8. International Centre for Eye Health, Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom8International Centre for Evidence in Disability, London School of Hyg
9. International Centre for Eye Health, Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom3National Institute for Health Research, Biomedical Research Centre, U