Night blindness

Vitamin A deficiency is a systemic disease caused by a lack of vitamin A in the body. The main pathological change is the development of keratinosis in the epithelial tissues of the body. Eye symptoms appear earlier and significantly, and the ability to adapt to the dark decreases, followed by conjunctiva, cornea dryness, and finally corneal softening, or even perforation, so there are night blindness, xerophthalmia, and corneal softening Disease (keratomalacia) and so on. The disease is more common in infants and young children with malnutrition and long-term diarrhea. The peak incidence is mostly between 1 and 4 years old, and it is rare in children over 6 years old.