British / Treatment Outcome / Cornea / Visual acuity / Diarrhea / Humans / Female / Pneumonia / Male / Infant / Socioeconomic Status / Clinical Sciences / Optometry and Ophthalmology / Public health systems and services research / Preschool Children / Corneal transplantation / Penetrating keratoplasty / Measles / Humans / Female / Pneumonia / Male / Infant / Socioeconomic Status / Clinical Sciences / Optometry and Ophthalmology / Public health systems and services research / Preschool Children / Corneal transplantation / Penetrating keratoplasty / Measles