This nutrient is most important for healthy vision:

Vitamin A is crucial for healthy vision because it's a component of rhodopsin, the pigment in retinal cells that enables vision in low light. It also maintains the cornea and conjunctival membranes. Vitamin A deficiency causes night blindness and can lead to complete blindness. Unlike Vitamin K (blood clotting), iron (oxygen transport), or calcium (bones), Vitamin A directly supports eye function.