The study sought to prevent blindness from microbial keratitis (MK) through addressing critical challenges in treatment, prevention and diagnosis. This was addressed by: (1) determining whether topical chlorhexidine is non-inferior to topical natamycin for fungal keratitis; (2) testing whether topical ilomastat can reduce corneal perforation from MK; (3) investigating whether an early primary-care intervention package, including topical chlorhexidine, can reduce blindness from MK; and (4) evaluating diagnostic approaches to identifying causative organisms.