An orbital tumor refers to any tumor located in the “orbit” or bony eye socket that contains the eye itself. The bony eye socket is a complicated structure that includes the eye itself along with delicate thin bones, muscles, nerves, and connective tissue that support the eye and its overall function. The eye socket is widest in the front and narrows toward the back, where the optic nerve leaves the socket and connects to the brain. Even a tiny tumor in this small, crowded space can cause significant symptoms, vision loss, eye movement restrictions and functional effects. Larger tumors can cause the eye to bulge forward and cause serious vision problems.