Anterior segment

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Anterior segment

Human Eye Anterior Segment - Magnified view seen on examination with a slit lamp under diffuse illumination showing conjunctiva overlying the white sclera, transparent cornea, pharmacologically dilated pupil and cataract

Schematic diagram of the human eye.
Latin	segmentum anterius bulbi oculi
Dorlands/Elsevier	s_07/13264628

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.^[1] ^[2]

Within the anterior segment are two fluid-filled spaces:

the anterior chamber between the posterior surface of the cornea (i.e. the corneal endothelium) and the iris.
the posterior chamber between the iris and the front face of the vitreous.^[1]

Aqueous humor fills these spaces within the anterior segment and provides nutrients to the surrounding structures.

Some ophthalmologists specialize in the treatment and management of anterior segment disorders and diseases.^[2]

[edit] References

^ ^a ^b Cassin, B. and Solomon, S. Dictionary of Eye Terminology. Gainsville, Florida: Triad Publishing Company, 1990.
^ ^a ^b "Departments. Anterior segment." Cantabrian Institute of Ophthalmology.

v • d • e Sensory system – Visual system – Eye

Fibrous tunic (outer)	Conjunctiva • Sclera • Schlemm's canal • Trabecular meshwork • Limbus Cornea (Epithelium, Bowman's, Stroma, Descemet's, Endothelium)

Uvea (middle)	Choroid (Ciliary processes, Choriocapillaris, Bruch's membrane) • Iris (Stroma) • Pupil • Ciliary body

Retina (inner)	Macula • Fovea • Optic disc • Tapetum lucidum

Anterior segment	Anterior chamber • Aqueous humour • Posterior chamber • Lens

Posterior segment	Vitreous humour • Zonule of Zinn

Intraocular muscles	parasympathetic (Ciliary muscle, Iris sphincter muscle) • sympathetic (Iris dilator muscle)

Appearance phenomena of the eye	Eyeshine • Leukocoria • Red-eye effect • Red reflex

Appearance phenomena by the eye	Color appearance (Abney effect • Bezold-Brücke shift • Chromatic adaptation • Purkinje effect)