Photoreceptors of the Retina

While researching the human retina I found its complex structure and physiology very intriguing. Light must penetrate a number of cell layers in order to reach two types of photoreceptor cells, namely rods and cones. The movement of light transduction begins at the photoreceptor cell layer and carries through up to the ganglion layer where the signal is sent to the optic nerve and further on to the brain. This illustration depicts the highest area of visual activity in the retina, the fovea, and was rendered in Adobe Photoshop CS4. Here, some of the cone cells, which are extensive in the fovea, have been removed to give a visual representation of the layered structure that is involved in signal transduction.