Cornea
The clear front window of the eye. The cornea transmits and focuses light into the eye. The eye has a number of other components. These include the iris, pupil, lens, retina, macula, optic nerve and vitreous. The iris is the colored part of the eye that helps regulate the amount of light that enters the eye. The pupil is the dark aperture in the iris that determines how much light is let into the eye. The lens is the transparent structure inside the eye that focuses light rays onto the retina. The retina is the nerve layer that lines the back of the eye, senses light and creates impulses that travel through the optic nerve to the brain. The macula is a small area in the retina that contains special light-sensitive cells and allows us to see fine details clearly. The optic nerve is the nerve that connects the eye to the brain and carries the impulses formed by the retina to the visual cortex of the brain. The vitreous humor is a clear, jelly-like substance that fills the middle of the eye.
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The transparent tissue constituting the anterior sixth of the outer wall of the eye, with a 7.7-mm radius of curvature as contrasted with the 13.5 mm of the sclera; it consists of stratified squamous epithelium continuous with that of the conjunctiva, a substantia propria, substantially regularly arranged collagen imbedded in mucopolysaccharide, and an inner layer of endothelium. It is the chief refractory structure of the eye. [L. fem. of corneus, horny]
- conical c. SYN: keratoconus.
- c. farinata bilateral speckling of the posterior part of the corneal stroma. SYN: floury c..
- floury c. SYN: c. farinata.
- c. plana a congenital disorder in which the arc curvature of the c. is flatter than normal, leaving the eye hyperopic.
- c. urica bilateral deposition of crystalline deposits of urea and sodium urate within corneal stroma.
- c. verticillata congenital whorl-like opacities in the c.. SYN: Fleischer vortex.

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cor·nea 'kȯr-nē-ə n the transparent part of the coat of the eyeball that covers the iris and pupil and admits light to the interior
cor·ne·al -əl adj

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n.
the transparent circular part of the front of the eyeball. It refracts the light entering the eye onto the lens, which then focuses it onto the retina. The cornea contains no blood vessels and it is extremely sensitive to pain. The innermost layer (corneal endothelium) consists of a single layer of cells that cannot regenerate.
corneal adj.

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cor·nea (korґne-ə) [L. corneus horny] [TA] the transparent structure forming the anterior part of the sclera of the eye. It consists of five layers: (1) the anterior corneal epithelium, continuous with that of the conjunctiva; (2) the anterior limiting layer (Bowman membrane); (3) the substantia propria, or stroma; (4) the posterior limiting layer (Descemet membrane); and (5) the endothelium of the anterior chamber. corneal adj


Medical dictionary. 2011.

Look at other dictionaries:

  • córnea — f. anat. Porción anterior de la esclerótica formada por una membrana transparente de forma curva, situada en la parte anterior del ojo (sobre el iris). Se encuentra ricamente inervada por filetes nerviosos de la rama oftálmica del nervio… …   Diccionario médico

  • Cornea — ist der Familienname folgender Personen: Doina Cornea (* 1929), rumänische Dissidentin und Menschenrechtlerin Carol Cornea, Pseudonym von Kurt E. Koch (1913–1987), evangelischer Theologe und Publizist Cornea ist die lateinische Bezeichnung für… …   Deutsch Wikipedia

  • cornea — late 14c., from M.L. cornea tela horny web or sheath, from L. cornu (gen. cornus) horn (see HORN (Cf. horn)). So called for its consistency. Related: Corneal …   Etymology dictionary

  • córnea — s. f. 1. Túnica espessa e transparente do olho. 2. córnea opaca: esclerótica …   Dicionário da Língua Portuguesa

  • córnea — sustantivo femenino 1. Área: anatomía Membrana dura y transparente del ojo, encajada en la esclerótica, a través de la cual se ve el iris: Vengo asustado del oculista, porque me ha dicho que tengo una lesión en la córnea …   Diccionario Salamanca de la Lengua Española

  • cornea — ► NOUN ▪ the transparent layer forming the front of the eye. DERIVATIVES corneal adjective. ORIGIN from Latin cornea tela horny tissue …   English terms dictionary

  • cornea — [kôr′nē ə] n. [ME < ML < L cornea (tela), horny (web, tissue), fem. sing. of corneus < cornu,HORN] the transparent tissue over the front of the eyeball, covering the iris and pupil: see EYE corneal adj …   English World dictionary

  • Cornea — Cor ne*a (k?r n? ?), n.; pl. {Corneas} ( ?z). [Fem. sing., fr. L. corneus horny, fr. cornu a horn. See {Horn}.] (Anat.) The transparent part of the coat of the eyeball which covers the iris and pupil and admits light to the interior. See {Eye}.… …   The Collaborative International Dictionary of English

  • Cornĕa [1] — Cornĕa, Dorf im Kreise Temes des österreichischen Verwaltungsgebietes Temesvar. (Ungarn). Hier am 4. Juli 1738 Überfall der Österreicher durch die Türken. Die Türken kamen bis ans Zelt des Großherzogs von Toscana, wurden aber geworfen …   Pierer's Universal-Lexikon

  • Cornĕa [2] — Cornĕa (lat.), die Hornhaut, s. u. Auge …   Pierer's Universal-Lexikon

  • Cornĕa — (lat.), die Hornhaut des Auges; s. Tafel »Auge II« (mit Text) …   Meyers Großes Konversations-Lexikon

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