The first sign of Vit A deficiency is :

Modified classification WHO (Xerophthalmia) XN : Night blindness XIA : Conjunctival xerosis XIB : Bitot’s spots X2: Corneal xerosis X3A : Corneal ulceration/keratomalacia less than 1/3rd corneal surface X3B : Corneal ulceration/keratomalacia equal to or more than 1/3rd corneal surface XS : Corneal scar XF : Xerophthalmia fundus.