system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Vitamin A deficiency is characterized by –
assistant
The correct answer is  The most characteristic and specific signs of vitamin A deficiency are eye lesions.
These develop before the age of 2 years.
The term xerophthalmia comprises all the occular manifestations of vitamin A deficiency.

Xerophthalmia (Dry eve) 

It is a syndrome due to deficiency of vitamin A.
It has following stages


Night blindness               -->  Earliest ocular symptom
Conjuctival xerosis         -->      Earliest ocular sign
Bitot's spot
Corneal xerosis
Keratomalacia & corneal ulcers