One topic that comes to mind which relates to my field of interest in the myelin sheath. Myelin is a fatty substance which insulates and protects axons, also functioning to speed up transmission speeds of action potentials. The gaps between myelin in these axons are called Nodes of Ranvier, and these nodes are where the action potential actually travels, skipping most of the axon thanks to the areas surrounded by myelin. I initially learned about myelin at my job at an optometry practice while I was examining a patient’s fundus image, and I saw prominent feathery-white striations. Those striations turned out to be myelinated nerve fibers, which stood out because the axons throughout our retinas typically do not have any myelin. This is because of two factors: First, the retina lacks oligodendrocytes, so the environment cannot produce myelin. Second, the optic nerve is formed around a structure called the lamina cribrosa, which is an export hub for all of the axons to gather and exit the retina, and also acts as a protective barrier against myelination. Myelinated axons in the retina are usually caused by malformations in the lamina cribrosa, and thankfully rarely cause any vision issues. Although, they are sometimes associated with higher risk for diseases like glaucoma. The technical knowledge on myelin that this course offered has helped deepen my understanding of this topic in relation to optometry.