Yes, deficiency of vitamin A can cause night blindness. Night blindness, just as its name implies, means one cannot see things clearly in the darkness. In the retina of eye ground exist pyramidal cells and tenuous rod cells, in which the light perception substance, namely rhodopsin exists. When entering in a dark place, the rhodopsin disappears and eyes are not sensitive to the light, so you cannot see things clearly. In normal condition, there is enough vitamin A in the human body, which promotes rhodopsin to regenerate under the function of retina and hepatic enzyme, hence recovering the sensitiveness to the light, making people see things in the darkness. But if the body lacks vitamin A, the rhodopsin is no longer regenerated, causing that people cannot see things clearly in the dark place, namely night blindness.
