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crystalline lens
crystalline lensn. The lens of the eye in vertebrates and certain invertebrates.crystalline lens n (Anatomy) a biconvex transparent elastic structure in the eye situated behind the iris, serving to focus images on the retina lens (lɛnz)
n., pl. lens•es. 1. a piece of transparent substance, usu. glass, having two opposite surfaces either both curved or one curved and one plane, used in optical devices for changing the convergence of light rays, as for magnification, or in correcting defects of vision. 2. a combination of such pieces. 3. some analogous device, as for affecting sound waves, electromagnetic radiation, or streams of electrons. 4. a doubly convex, transparent body in the eye, behind the pupil, that focuses incident light on the retina. 5. a body of rock or ore that is thick in the middle and thinner toward the edges, similar in shape to a biconvex lens. [1685–95; < New Latin; Latin lēns a lentil (a lens so called from its shape); compare lentil] Thesaurus| Noun | 1. |  crystalline lens - biconvex transparent body situated behind the iris in the eye; its role (along with the cornea) is to focuses light on the retinalens of the eye, lensorgan - a fully differentiated structural and functional unit in an animal that is specialized for some particular functioneye, oculus, optic - the organ of sightlens cortex, cortex - the tissue that surrounds the lens nucleuslens capsule - a tenuous mesoblastic membrane surrounding the lens of the eye |
TranslationsCrystalline Lens
crystalline lens[′kris·tə·lən ′lenz] (anatomy) lens Crystalline Lens a lenticular transparent body (convex lens) of the eye located behind the iris and opposite the pupil; part of the light-refractive (dioptric) system of the eye in vertebrates, including humans. The crystalline lens is divided structurally into the anterior epithelium of the cornea and the body, which consists of fibers and intercellular cementing substances. Externally it is clad in a capsule—an elastic membranous envelope. The lens has anterior and posterior surfaces, with corresponding anterior and posterior poles through which the optical axis of the eye passes. The maximum circumference on the lateral surface in a plane perpendicular to the optical axis is called the equator of the lens. The annular Zinn’s ligament is attached to the capsule at the equator; change in its tension changes the curvature of the lens surface, as a result of which accommodation is effected in higher vertebrates. In fishes and amphibians the lens is suspended by a ligament and during accommodation moves away from or toward the retina by means of a special muscle. In embryonic development the lens is formed from the covering epithelium under the inductive influence of the eye rudiment. Water constitutes about 65 percent of the lens, and proteins 35 percent. The crystalline lens of vertebrates grows throughout life. With age the lens scleroses, and there is a consequent weakening of accommodation (presbyopia). The most common pathological change in the lens is opacification, that is, the formation of cataracts. O. G. STROEVA crystalline lens
lens [lenz] 1. a piece of glass or other transparent material so shaped as to converge or scatter light rays. See also glasses.2. the transparent, biconvex body separating the posterior chamber and the vitreous body of the eye; it refracts (bends) light rays so that they are focused on the retina. Called also crystalline lens. In order for the eye to see objects close at hand, light rays from the objects must be bent more sharply to bring them to focus on the retina; light rays from distant objects require much less refraction. It is the function of the lens to do accommodation, making of adjustments for viewing both near objects and more distant ones. To accomplish this it must be highly elastic so that its shape can be changed and made more or less convex. The more convex the lens, the greater the refraction. Small ciliary muscles create tension on the lens, making it less convex; as the tension is relaxed the lens becomes more spherical in shape and hence more convex.
With increasing age the lenses lose their elasticity; thus their ability to focus light rays in the retina becomes impaired. This condition is called presbyopia. In farsightedness (hyperopia) the image is focused behind the retina because the refractive power of the lens is too weak or the eyeball axis is too short. Nearsightedness (myopia) occurs when the refractive power of the lens is too strong or the eyeball is too long, so that the image is focused in front of the retina. The biconvex lens of the eye. From Frazier et al., 1996.achromatic lens one corrected for chromatic (color) aberration.apochromatic lens one corrected for chromatic (color) and spheric aberration.biconcave lens one concave on both faces.biconvex lens one convex on both faces.bifocal lens one having two segments with different refracting power, the upper for far vision and the lower for near vision. See also bifocal glasses" >bifocal glasses.concave lens one curved like a section of the interior of a hollow sphere; it disperses light rays. Called also diverging lens.contact l's corrective lenses that fit directly over the cornea of the eye; see also contact lenses.converging lens (convex lens) one curved like the exterior of a hollow sphere; it brings light to a focus.convexoconcave lens one that has one convex and one concave face.crystalline lens lens (def. 2).cylindrical lens one with at least one nonspherical surface, used to correct astigmatism.diverging lens concave lens.honeybee lens a magnifying eyeglass lens designed to resemble the multifaceted eye of the honeybee. It consists of three or six small telescopes mounted in the upper portion, directed toward the center and right and left visual fields. Prisms are included to provide a continuous, unbroken magnified field of view.omnifocal lens one whose power increases continuously and regularly in a downward direction, avoiding the discontinuity in field and power inherent in bifocal and trifocal lenses.orthoscopic lens one that gives a flat and undistorted field of vision, especially at the periphery.planoconcave lens a lens with one plane and one concave side.planoconvex lens a lens with one plane and one convex side.Stokes's l's an apparatus used in the diagnosis of astigmatism" >astigmatism.trial l's ones used in testing the vision.trifocal lens one having three segments of different refracting powers, the upper for distant, the middle for intermediate, and the lower for near vision.lens (lenz), [TA] Avoid the misspelling lense.1. A transparent material with one or both surfaces having a concave or convex curve; acts on electromagnetic energy to cause convergence or divergence of light rays. 2. The transparent biconvex cellular refractive structure lying between the iris and the vitreous humor, consisting of a soft outer part (cortex) with a denser part (nucleus), and surrounded by a basement membrane (capsule); the anterior surface has a cuboidal epithelium, and at the equator the cells elongate to become lens fibers. Synonym(s): crystalline lens [L. a lentil] crystalline lensn. The lens of the eye in vertebrates and certain invertebrates.crystalline lens The internal, fine-focusing, lens of the eye, which lies immediately behind the iris diaphragm and is suspended by a delicate ligament from the CILIARY BODY. In youth the lens is elastic and changes shape easily. Elasticity, and range of focusing power, fall off almost linearly with age.Lens (or crystalline lens)The eye structure behind the iris and pupil that helps focus light on the retina.Mentioned in: PresbyopiaPatient discussion about crystalline lensQ. My neighbor's kid had a lens dislocation due to Marfan's disease. Is this a contagious thing? My neighbor's have a sweet 8 year old boy. he had a lens dislocation due to a connective tissue disease named Marfan (I think that the name). It sounds like a very serious condition. My boy is playing with this kid several hour a week. should I take him to the GP to see that his is not infected with this marfan thing?A. As in love and war so is in medicine the is no always nor never. It is probably the marfan that caused your neighbor kid the lens dislocation but you can never know for sure.
If you want there is nothing wrong in taking your boy for an annual check of an ophthalmologist. More discussions about crystalline lenscrystalline lens
Related to crystalline lens: lens subluxationSynonyms for crystalline lensnoun biconvex transparent body situated behind the iris in the eyeSynonymsRelated Words- organ
- eye
- oculus
- optic
- lens cortex
- cortex
- lens capsule
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