Which vitamin is critical for maintaining healthy vision?

Vitamin A is essential for maintaining healthy vision primarily due to its role in the formation of rhodopsin, a protein in the retina that is necessary for low-light and color vision. This vitamin enables the eyes to adapt to varying levels of light, which is crucial for proper visual function. Additionally, Vitamin A contributes to the health of the cornea and supports the overall functioning of the eye.

While other vitamins also play important roles in vision and eye health, they do not have the same direct impact as Vitamin A does in terms of visual processing. Vitamin B12 is vital for nerve health and the production of red blood cells, Vitamin C serves as an antioxidant and supports eye health but is not as directly involved in vision, and Vitamin D is important for bone health and may have a role in eye tissue health but does not directly affect visual acuity or light perception. Thus, the critical connection between Vitamin A and vision establishes it as the correct answer in this context.