Keratomalacia is:
a) Extreme dryness of the conjunctiva resulting from a disease localized in the eye or from systemic deficiency of vitamin A
b) A condition, usually in children with vitamin A deficiency, characterized by softening and subsequent ulceration and perforation of the cornea
c) A visual defect marked by the inability to see as clearly in bright light as in dim light
d) All of the above
