1. Aravind Eye Care System, Madurai, India
2. Francis I. Proctor Foundation, University of California, San Francisco
3. Francis I. Proctor Foundation, University of California, San Francisco3Department of Epidemiology and Biostatistics, University of California, San Francisco4Department of Ophthalmology, University of California, San Francisco
4. Francis I. Proctor Foundation, University of California, San Francisco4Department of Ophthalmology, University of California, San Francisco5Department of Optometry, University of California, Berkeley