Human eye anatomy

Schlemm's canal is a circular lymphatic-like vessel in the eye that collects aqueous humor from the anterior chamber and delivers it into the episcleral blood vessels via aqueous veins.

The choroid, also known as the choroidea or choroid coat, is the vascular layer of the eye, containing connective tissue, and lying between the retina and the sclera.

The lacrimal canaliculi, (sing. canaliculus), also known as the lacrimal canals or lacrimal ducts, are the small channels in each eyelid that commence at minute orifices, termed puncta lacrimalia, on the summits of the papillae lacrimales, seen on the margins of the lids at the lateral extremity of the lacus lacrimalis.

At the basal angles of the lacus lacrimalis, on the margin of each eyelid, is a small conical elevation, the lacrimal papilla, the apex of which is pierced by a small orifice, the punctum lacrimale, the commencement of the lacrimal duct.

The lacrimal punctum (plural puncta) or lacrimal point, is a minute opening on the summits of the lacrimal papillae, seen on the margins of the eyelids at the lateral extremity of the lacrimal lake.

The palpebral fissure is the elliptic space between the medial and lateral canthi of the two open lids.

The zonule of Zinn (Zinn's membrane, ciliary zonule) (after Johann Gottfried Zinn) is a ring of fibrous strands connecting the ciliary body with the crystalline lens of the eye.

The vitreous membrane (or hyaloid membrane or vitreous cortex) is a layer of collagen separating the vitreous humour from the rest of the eye.

The inner limiting membrane is the boundary between the retina and the vitreous body, formed by astrocytes and the end feet of Müller cells.

The stroma of the iris is a fibrovascular layer of tissue.

The foveola is located within a region called the macula, a yellowish, cone photo receptor filled portion of the human retina.

The aqueous humour is a transparent, watery fluid similar to plasma, but containing low protein concentrations.

The conjunctiva lines the inside of the eyelids and covers the sclera (the white of the eye).

The lens is a transparent, biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina.

The nasolacrimal duct (sometimes called the tear duct) carries tears from the lacrimal sac into the nasal cavity.

The retina (UK /ˈrɛtɪnə/ RET-i-nə, US /ˈrɛtᵊnə/ RET-(ə-)nə, pl. retinae, /ˈrɛtiniː/; from Latin rēte, meaning "net") is the third and inner coat of the eye which is a light-sensitive layer of tissue.

The sclera, also known as the white of the eye, is the opaque, fibrous, protective, outer layer of the eye containing collagen and elastic fiber.

Epicanthic fold (/ɛpɪˌkænθɪkˈfoʊld/), epicanthal fold, epicanthus, and eye fold are names for a skin fold of the upper eyelid, covering the inner corner (medial canthus) of the eye.

An eyelash or simply lash is one of the hairs that grows at the edge of the eyelid.

The lateral rectus muscle is a muscle on the lateral side of the eyeball in the orbit.

The superior oblique muscle, or obliquus oculi superior, is a fusiform muscle originating in the upper, medial side of the orbit (i.e. from beside the nose) which abducts, depresses and internally rotates the eye.

The uvea (Lat. uva, grape), also called the uveal layer, uveal coat, uveal tract, or vascular tunic, is the pigmented middle of the three concentric layers that make up an eye.

The extraocular muscles are the six muscles that control movement of the eye (there are four in bovines) and one muscle that controls eyelid elevation (levator palpebrae).

The inferior rectus muscle is a muscle in the orbit.

The lacrimal apparatus is the physiological system containing the orbital structures for tear production and drainage.

The superior rectus muscle is a muscle in the orbit.

The pigmented layer of retina or retinal pigment epithelium (RPE) is the pigmented cell layer just outside the neurosensory retina that nourishes retinal visual cells, and is firmly attached to the underlying choroid and overlying retinal visual cells.

Glands of Zeis are unilobar sebaceous glands located on the margin of the eyelid.

Glands of Moll, also known as ciliary glands, are modified apocrine sweat glands that are found on the margin of the eyelid.

The lacrimal caruncle, or caruncula lacrimalis, is the small, pink, globular nodule at the inner corner (the medial canthus) of the eye.

The periorbita is the area around the orbit.

The suspensory ligament of eyeball (or Lockwood's ligament) forms a hammock stretching below the eyeball between the medial and lateral check ligaments and enclosing the inferior rectus and inferior oblique muscles of the eye.

The ciliary processes are formed by the inward folding of the various layers of the choroid, i.

The trochlea of superior oblique is a pulley-like structure in the eye.

The corneal endothelium is a single layer of cells on the inner surface of the cornea.

The inner plexiform layer is an area of the retina that is made up of a dense reticulum of fibrils formed by interlaced dendrites of retinal ganglion cells and cells of the inner nuclear layer.

The outer nuclear layer (or layer of outer granules or external nuclear layer), is one of the layers of the vertebrate retina, the light-detecting portion of the eye.

The outer plexiform layer (external plexiform layer) is a layer of neuronal synapses in the retina of the eye.

The posterior segment is the back two-thirds of the eye that includes the anterior hyaloid membrane and all of the optical structures behind it: the vitreous humor, retina, choroid, and optic nerve.

Ophthalmic veins are veins which drain the eye.

The Orbital Fascia forms the periosteum of the orbit.

The pupil is a hole located in the centre of the iris of the eye that allows light to strike the retina.

The trabecular meshwork is an area of tissue in the eye located around the base of the cornea, near the ciliary body, and is responsible for draining the aqueous humor from the eye via the anterior chamber (the chamber on the front of the eye covered by the cornea).

The fundus of the eye is the interior surface of the eye opposite the lens and includes the retina, optic disc, macula, fovea, and posterior pole.

The ciliary muscle /ˈsɪli.

The posterior surfaces of the ciliary processes are covered by a bilaminar layer of black pigment cells, which is continued forward from the retina, and is named the pars ciliaris retinae.

The Bowman's membrane (Bowman's layer, anterior limiting lamina, anterior elastic lamina) is a smooth, acellular, nonregenerating layer, located between the superficial epithelium and the stroma in the cornea of the eye.

The fovea centralis (the term fovea comes from the Latin, meaning pit or pitfall) is a small, central pit composed of closely packed cones in the eye.

The anterior chamber (AC) is the fluid-filled space inside the eye between the iris and the cornea's innermost surface, the endothelium.

The anterior segment is the front third of the eye that includes the structures in front of the vitreous humour: the cornea, iris, ciliary body, and lens.

The corneal epithelium (epithelium corneæ anterior layer) is made up of epithelial tissue and covers the front of the cornea.

The corneal limbus is the border of the cornea and the sclera (the white of the eye).

The episclera is the outermost layer of the sclera.

The iris sphincter muscle (pupillary sphincter, pupillary constrictor, circular muscle of iris, circular fibers) is a muscle in the part of the eye called the iris.

The fascia bulbi (also known as the capsule of Tenon and the bulbar sheath) is a thin membrane which envelops the eyeball from the optic nerve to the limbus, separating it from the orbital fat and forming a socket in which it moves.

The tarsi (tarsal plates) are two comparatively thick, elongated plates of dense connective tissue, about 2.

The vitreous chamber is the space in the eye occupied by vitreous humor.

The periscleral lymph space or episcleral space of the eye is the space between the outer surface of the sclera and the inner surface of the capsule of Ténon.

The sclera and cornea form the fibrous tunic of the bulb of the eye; the sclera is opaque, and constitutes the posterior five-sixths of the tunic; the cornea is transparent, and forms the anterior sixth.

The plica semilunaris is a small fold of bulbar conjunctiva on the medial canthus of the eye.

The lens capsule is a component of the globe of the eye.

The optic cup is the white, cup-like area in the center of the optic disc.

The medial palpebral ligament (medial canthal tendon) is about 4 mm in length and 2 mm in breadth.

Canthus (pl. canthi, palpebral commissures) is either corner of the eye where the upper and lower eyelids meet.

Descemet's membrane is the basement membrane that lies between the corneal proper substance, also called stroma, and the endothelial layer of the cornea.

The globe of the eye, or bulbus oculi, is the eyeball apart from its appendages.

The optic disc or optic nerve head is the point of exit for ganglion cell axons leaving the eye.

Circulus arteriosus minor or minor arterial circle of iris is an arterial circle near the pupillary margin of the iris.

The annulus of Zinn, also known as the annular tendon or common tendinous ring, is a ring of fibrous tissue surrounding the optic nerve at its entrance at the apex of the orbit.