Finally, as promised, one of my scanning electron micrographs. This one is of the ends of photoreceptors. Rods to be precise. You may all remember them as the light/dark photoreceptors, while cones are the colour/high acuity ones. The eye is organized is a very counterintuitive way, first the light passes through many layers of cells, then it hits the photoreceptors, then the signal travels back up through the layers of cells then out through the optic nerve.