Lateral inhibition by illuminated rods and cones creates a higher contrast in the perceived image.
Work Step by Step
Illuminated rods and cones are hyperpolarized, which causes them to stop releasing glutamate. Glutamate depolarizes bipolar cells, so when its production drops these cells also hyperpolarize. Horizontal cells stimulated by this process inhibit more distant bipolar cells from hyperpolarizing. The effect is a higher contrast image.