In this video I will teach you all about the eye. Specifically, we will learn about its basically parts and how they work. We will look at, in-depth, the muscles of the eye, how they work, their nerve innervation, and how they are tested [reference, Gray's Anatomy]. We will also look at what controls the size of the pupil - learn about the interplay between parasympathetic innervation and sympathetic innervation and the key iris muscles: sphincter pupillae and dilator pupillae.