Myelin is the insulation around the nerves in our bodies. This myelin helps the electric signal to travel down the nerve in greater efficiency. As the nerve fibers enter the eye, however, they lose their myelin. Sometimes the myelin continues into the retina as an interesting anomoly. Usually the myelin is near the optic nerve. But in this case, there is myelin around the nerve fibers in the peripheral retina, as you can see in the photo. This myelin has no consequence to this patients vision and there is no danger in this small extent.