Anatomic and tumor-specific factors play dominant roles in clinical decision-making. Select examples include eye¬lid tumor position directing the postresection method of repair (see Chapter 37), orbital optic nerve sheath obstruction requiring slotted plaques (see Chapter 18) to completely cover juxtapapillary intraocular tum¬ors, and the shape of the orbit affecting the orbitotomy approach. In consideration of the basic anatomy of the eyeball, the adnexa, and the orbit, this chapter high¬lights select salient anatomical features that affect tumor growth, metastasis (regional or distant), diagnosis, and management.