Deficiency of which vitamin causes night blindness?

Night Blindness is caused by the deficiency of Vitamin-A.
Night blindness is the difficulty for the eyes to adjust to dim light. Affected individuals have poor vision in the darkness but see normally when adequate light is present.
A deficiency of vitamin A is a lack of vitamin A in blood and tissues. Vitamin A deficiency is the world's leading cause of preventable childhood blindness.
Concentrations of preformed vitamin A are highest in the liver, fish, eggs, dairy products, and orange and other yellow fruits and vegetables.