Answer: This is because vision in a low light condition DEPENDS ON THE RODS.
Explanation: A rod is a cell shaped like a 'rod' found in the eyes that is sensitive to light. They are photoreceptors and function efficiently well in low light than the other types of cells found in the eyes, cone cells.
They are essentially responsible for night vision.
Jane's peripheral vision was better than her central vision because as the room was darkened, he rod responsible for low light vision was in full activeness.