This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
Blindness in a child is most commonly due to - 
Select and explain. 
A. Keratomalacia, B. Congenital cataract, C. Glaucoma, D. Injuries
A: Keratomalacia
Answer: A: Keratomalacia 
Explanation: Keratomalacia is due to vitamin A deficiency.

"Vitamin A deficiency is the most common cause of blindness in children in India". __ Philip Reily
"Vitamin A deficiency is the single most important cause of blindness in children". — Wykoff