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
Xerophthalmia is a public health problem if prevalence of bitot spots is
assistant
The correct answer is  Night blindness : > 1%.
Bitot spots : >0.5%.
Corneal ulcer : >0.05%.
Corneal xerosis : >0.01%.