The optic disk contains no photoreceptors and therefore is a blind spot. Photoreceptors transduce visual signals. They are hyperpolarized by light. Pathways through the retina involve relays by retinal interneurons. Bipolar pathways are more direct than amacrine ones.
Horizontal cells mediate lateral inhibition.
Amacrine cells and some ganglion cells have large, diffuse receptive fields. The LGN projects to the striate cortex through the optic radiation. Part of the axons extend into the temporal lobe in Meyer's loop. These carry visual information from the lower retinas and thus represent the contralateral upper visual field quadrants. The LGN projection ends largely in layer 4 of the striate cortex.