Beauty is in the eye of the beholder.
The mature retina contains five classes of neurons: photoreceptors (purple), horizontal cells (yellow), bipolar neurons (green), amacrine cells (pink and blue), and ganglion cells (pink and blue). The outersegments of the cone photoreceptors point up, into the retinal pigmented epithelium, and their axons point down, terminating in end feet (white) that form synapses with horizontal (yellow) and bipolar neurons (green). Bipolar cells connect photoreceptors directly to the ganglion cells, which transmit visual information to the brain, or to amacrine cells, which modulate the output of the bipolar cells.
In this cross section of an adult mouse retina, only a subset of bipolar cells, “the ON bipolar cells” are visible by their expression of GFP. The pink and blue speckled striations at the bottom of the image mark the fiber layer, which contains the ganglion cell axons that will form the optic nerve.
(Picture by Rachel Wong, University of Washington).