Linked from
The 15 pages that link to Rod cell, each with the reason it gives.
Optic nerveBroader topic: Rod signals pass through retinal circuits before entering the optic nerve.
RhodopsinNarrower topic: Rhodopsin is the defining visual pigment housed in rod cells.
Night visionBroader topic: Rods provide most human vision after light levels fall.
Human visual systemBroader topic: Rods carry night vision and dominate the peripheral retina.
MonochromacyRelated: In rod monochromacy, rods provide the principal visual signal.