What is the function of vitamin A in vision?

Vitamin A plays a crucial role in vision primarily through its involvement in the formation of rhodopsin, a light-sensitive pigment found in the retina. Rhodopsin is essential for the phototransduction process—the conversion of light into electrical signals, which are then transmitted to the brain to be interpreted as images. Without sufficient vitamin A, the synthesis of rhodopsin is impaired, leading to difficulty in low-light conditions and potentially resulting in night blindness.

While vitamin A has several functions related to eye health, including maintaining the integrity of the cornea and supporting tear production, its most critical role in vision is through rhodopsin production. This is why the correct answer emphasizes its importance in the retina for light detection.