Scotopic vision Scotopic vision Scotopic vision is the vision of the eye under low-light levels. The term comes from Greek "skotos", meaning "darkness", and "-opia", meaning "a condition of sight". In the human eye, cone cells are nonfunctional in low visible light. Scotopic vision is produced exclusively through rod cells, which are most sensitive to wavelengths of around 498 nm (green–blue) and are insensitive to wavelengths longer than about 640 nm (red). This condition is called the Purkinje effect. Scotopic vision is dominated by retina amacrine cells, specifically AII-amacrine cells. AII-amacrine cells capture rod bipolar cell input and redistribute it to cone
Retina density of rods converging on single bipolar cells. Since its cones have a much lesser convergence of signals, the fovea allows for the sharpest vision the eye can attain. Though the rod and cones are a mosaic of sorts, transmission from receptors, to bipolars, to ganglion cells is not direct. Since there are about 150 million receptors and only 1 million optic nerve fibres, there must be convergence and thus mixing of signals. Moreover, the horizontal action of the horizontal and amacrine cells can allow one area of the retina to control another (e.g. one stimulus inhibiting another). This inhibition