Structure of eye

Orbit (anterior view) The eyes are essential for our daily experience, since about 70% of information we gather is by seeing. They are placed within the Besides the eyes, the orbits host several structures that support the This page will discuss the Key facts about the orbit and eyes Orbit definition Bony cavity within the skull that houses the eye and its associated structures (muscles of the eye, eyelid, periorbital fat, lacrimal apparatus) Bones of the orbit Maxilla, zygomatic bone, frontal bone, ethmoid bone, lacrimal bone, sphenoid bone and palatine bone Structure of the eye Cornea, anterior chamber, lens, vitreous chamber and retina Muscles of the eye Extrinsic: Superior rectus, inferior rectus, medial rectus, lateral rectus, superior oblique, inferior oblique, levator palpebrae superioris Intrinsic: Innervation of the eye Vision: Optic nerve (CN II) Muscles: Oculomotor (CN III), trochlear (CN IV) and abducens (CN VI) nerves Blood supply of the eye Ophthalmic artery, vorticose veins + Show all Bones of the orbit The The walls of the orbit contain several fissures, openings and fossae which are important for housing the orbital structures, and for neurovascular communication of the orbital content with the central nervous system. Some of the most important openings are the superior orbital fissure and its downstairs neighbour, the inferior orbital fissure. More about them and all the other landmarks of the orbital bones can be found in the following article and quizze...

human eye, in Anatomy of the visual apparatus Structures auxiliary to the eye The The eye is protected from mechanical injury by being enclosed in a socket, or orbit, which is made up of portions of several of the bones of the skull to form a four-sided pyramid, the apex of which points back into the The It is vitally important that the front surface of the eyeball, the canthus, and the other is the outer canthus. The lid may be divided into four layers: (1) the skin, containing glands that open onto the surface of the lid margin, and the eyelashes; (2) a muscular layer containing principally the tarsal plates, which border directly upon the opening between the lids, called the palpebral aperture; and (4) the innermost layer of the lid, a portion of the The conjunctiva The conjunctiva lines the lids and then bends back over the surface of the eyeball, palpebral portion of the conjunctiva; the portion covering the white of the eyeball is called the bulbar conjunctiva. Between the bulbar and the palpebral conjunctiva there are two loose, conjunctival sacs; it is the looseness of the conjunctiva at these points that makes movements of lids and eyeball possible. Facts You Should Know: The Human Body Quiz The fibrous layer The fibrous layer, which gives the lid its mechanical stability, is made up of the thick, and relatively rigid, tarsal plates, bordering directly on the palpebral aperture, and the much thinner palpebral fascia, or sheet of connective tissue; the two together...

The human eye has several structures that enable entering light energy to be converted to electrochemical energy. This stimulates the visual centres in the brain, giving us the sensation of seeing. In this interactive, you can label parts of the human eye. Use your mouse or finger to hover over a box to highlight the part to be named. Drag and drop the text labels onto the boxes next to the eye diagram If you want to redo an answer, click on the box and the answer will go back to the top so you can move it to another box. If you want to check your answers, use the ‘Reset incorrect’ button. This will reset incorrect answers only. When you are happy with your selection, use the ‘Check answers’ button to check them. Use ‘Reset all’ to practise again from the start. Selecting or hovering over a box will highlight each area in the diagram. For optimal viewing of this interactive, view at your screen’s default zoom setting (100%) and with your browser window view maximised. See the Use the DOWNLOAD EXERCISE button for a PDF version of this interactive.