Answer:
Orbit bones (7): Includes the zygoma, lesser and greater wings of the sphenoid, frontal bone, ethmoid bone, lacrimal bone, palatine bone, maxilla.
Optic foramen: located within the substance of the lesser wing of the sphenoid, medial to the superior orbital fissure.
Superior orbital fissure: 22-mm cleft runs outward, forward, and upward from the apex of the orbit; separates the greater and lesser wings of the sphenoid; provides passage to CN III, IV, VI and V1 (ophthalmic branch).
Inferior orbital fissure: Separates the greater sphenoid wing portion of the lateral wall from the floor; permits passage of V2 (maxillary branch), infraorbital artery, branches of sphenopalatine ganglion, branches of the inferior ophthalmic vein to the pterygoid plexus.
Anterior & posterior ethmoidal foramina: Located between the roof and the medial wall of the orbit. Anterior ethmoidal foramen contains anterior ethmoidal artery and anterior ethmoidal branch of nasociliary nerve; posterior foramen contains posterior ethmoidal artery and the sphenoethmoidal branch of the nasociliary nerve.
Supraorbital notch (a true foramen in 25%): Contains the supraorbital artery and nerve.
Infraorbital foramen: Located in the maxilla (10 mm inferior to the zygomaticomaxillary suture); contains infraorbital nerve and vessels.
Whitnall's tubercle: 10 mm inferior to the frontozygomatic suture, 3 mm within the orbit; attachment for lateral canthal tendon, the check ligament of the lateral rectus muscle, the suspensory ligament of Lockwood, and the lateral extension of the aponeurosis of the levator muscle.
Lockwood's ligament: A hammock-like system with contributions from the inner muscular septae, Tenon's capsule, and the lower eyelid retractors. Posteriorly, it arises from fibrous attachments from the inferior side of the inferior rectus muscle and continues anteriorly as the capsulopalpebral fascia and lower eyelid retractors. Medially, it attaches to the posterior lacrimal crest; laterally, attaches to Whitnall's tubercle.
Whitnall's ligament: A condensation of the sheath overlying the anterior superior part of the levator muscle. Medially, arises posterior to the trochlea; laterally, attaches to the capsule of the orbital lobe of the lacrimal gland and to the frontal bone about 10 mm above the lateral orbital tubercle.
Canalicular anatomy: Tears collect along the border of each lid, and during blinking the fluid moves medially toward the upper and lower puncta. The canaliculi are approximately 10 mm long, and consist of a vertical part (2 mm long) and a horizontal component (8 mm long). In 90% of patients, the two canaliculi join to form a single common duct that opens into the lacrimal sac just posterior and superior to the lateral wall of the sac. The lacrimal sac extends above the medial canthal tendon by 3-5 mm. Inferiorly, it narrows to an isthmus and becomes the nasolacrimal duct. The combined length of the sac and duct is 30 mm. It enters the nasal cavity under the inferior turbinate via the valve of Hasner.
Orbital fat compartments: The upper lid contains two fat compartments - medial and lateral; the lower lid contains 3 compartments - medial, central and lateral. The inferior oblique muscle lies between the medial and central fat compartments. The medial fat compartment in the upper lid contains two individual fat pads (completely separated in 17%, separated to half their length in 46%, and separated at their tips only in 38%).