Xerophthalmia, a condition involving the hardening of the cornea of the eye, is caused by the deficiency of

Step-by-step solution

According to NCERT, Xerophthalmia (hardening of the cornea of the eye) is caused by the deficiency of Vitamin A. The chemical name of Vitamin A is Retinol. Ascorbic acid is Vitamin C (deficiency causes scurvy), Calciferol is Vitamin D (deficiency causes rickets and osteomalacia), and Tocopherol is Vitamin E (deficiency causes increased fragility of RBCs and muscular weakness). Answer: Retinol