Final answer:
The anterior transparent part of the fibrous tunic is known as the cornea, which functions as a window by allowing light into the eye for visual processing.
Step-by-step explanation:
The cornea functions as your "window on the world" by allowing light to enter the eye, where it can then be focused and processed to form visual images. Anatomy of the Visual System explains that the cornea is the transparent covering over the eye that serves as a barrier and is involved in focusing light waves. Along with the lens, the cornea works to form a real image on the retina, particularly concentrated at the fovea, which is the point of highest visual acuity.