From what we know, the human eye is anything but simple. Though it may look like nothing more than merely a white sphere with a central coloured ring at its anterior that encircles a small dark opening, that is just the tip of the iceberg. Within this hollow, 6-cubic-centimetre globe is over two million interacting parts that work to ensure light is gathered and processed into visual information as smoothly as possible. Its enormous complexity relative to its small size is the reason that the eye is considered the second most complex organ in the human body after the brain. This gorgeous, highly resilient organ can adjust accordingly to changing conditions and environments within a matter of milliseconds. The human eye is incredibly productive, working nonstop to manipulate the laws of physics by altering the trajectories and angles of incoming electromagnetic radiation, initiating biochemical pathways in our retinae to form visual details that biologically make sense. The fact that light entering our eyes from all different directions and distances is focused and projected onto our retinae as a clear, 2D image, and then information from that 2D image is used in our brain to construct 3D images that allow us to perceive the world in three dimensions is truly a work of genius by nature. Even the muscles that surround the bulb of the eye and regulate its movements are the swiftest and most powerful muscles in the human body relative to their function. Just like how the eye is the window to the outside world, this book is a window into the anatomical structures that form this biological powerhouse of energy-converting cells that help us discern vision.