What defines rod-cone dystrophy?

Rod-cone dystrophy is a type of retinal degeneration that primarily affects the photoreceptor cells in the retina, specifically the rods and cones. The correct choice, which describes a progressive decrease in night vision followed by a loss of detail vision, aligns well with the clinical presentation of this condition.

In the early stages of rod-cone dystrophy, individuals often experience nyctalopia, or difficulty seeing in low light conditions, which is predominantly due to the malfunction of rod photoreceptors. As the disease progresses, not only does night vision decline, but there is also a deterioration in central vision, affecting the ability to see fine details. This pattern of vision loss is characteristic and provides a clear understanding of the disease's impact on visual function over time.

The other options describe scenarios that do not accurately reflect the symptoms and progression of rod-cone dystrophy. Enhanced color vision and progressive increase in peripheral vision are inconsistent with the effects of rod-cone dystrophy, which generally leads to vision deficits. Immediate loss of all visual functions is not typical, as the condition progresses gradually rather than causing an abrupt loss of vision.