If a patient exhibits impaired night vision despite normal retinal structure, which consequence of vitamin A deficiency dominates?

💡 Explanation

Vitamin A is a precursor to retinal, a component of rhodopsin, which is critical for rod function in low light; therefore, vitamin A deficiency impairs rhodopsin production and causes night blindness, rather than affecting cone sensitivity or macular pigment because rods mediate dim-light vision.

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