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Encyclopedia > Lens (vision)
Light from a single point of a distant object and light from a single point of a near object being brought to a focus by changing the curvature of the lens.
Light from a single point of a distant object and light from a single point of a near object being brought to a focus by changing the curvature of the lens.

The lens or crystalline lens is a component of the eye. In concert with the cornea, it refracts light, focussing it onto the retina. Redrawing of Image:Focus in an eye. ... An eye is an organ that detects light. ... The cornea is the curved, transparent layer that covers the front part of the eye and protects its inner structures. ... Prism splitting light Light is electromagnetic radiation with a wavelength that is visible to the eye or, in a technical or scientific setting, electromagnetic radiation of any wavelength. ... FOCUS is a software product of Information Builders Inc. ... Human eye cross-sectional view. ...


The lens is clear and flexible; its curvature is controlled by ciliary muscles. By changing the curvature of the lens, one can focus the eye on objects at different distances from it. This process is called accommodation. The ciliary muscle is a muscle that affects zonules in the eye (fibers that suspend the lens in position during accommodation), enabling changes in lens shape for light focusing. ... Human eye The Accommodation Reflex is a reflex action of the eye, in response to focusing on a near object, then looking at distant object (and vice versa). ...


The lens is about 5 mm wide and has a diameter of about 9 mm for an adult human (though these figures can vary). The lens is included into the capsular bag, maintained by the zonules of Zinn.


During the fetal stage, the development of the lens is aided by the hyaloid artery. In adults, the lens depends entirely upon the aqueous and vitreous humors for nourishment. Fetus at eight weeks A fetus (alternatively foetus or fœtus) is an unborn vertebrate offspring after the embryonary stage. ... The hyaloid artery is a branch of the ophthalmic artery, which is itself a branch of the carotid artery. ... The aqueous humour is the clear, watery fluid that fills the complex space in the front of the eye which is bounded at the front by the cornea and at the rear by the front surface or face of the vitreous humour. ... Vitreous humour is the clear gel that fills the eyeball, lying between the lens and the retina in the eye. ...


Diseases of the eye

  • A cataract is when the normally transparent crystalline lens develops opacities and leads to blurry vision.

A cataract is a large waterfall or place where the flow of a river changes dramatically. ...

See also



An eye is an organ that detects light. ... This article needs to be cleaned up to conform to a higher standard of quality. ... The human iris The iris is the grey-brown area. ... A lens is a device for either concentrating or diverging light, usually formed from a piece of shaped glass. ... Phacoemulsification refers to modern cataract surgery in which the human lens is emulsified with an ultrasonic handpiece which employs irrigation of balanced salt solution for aspiration of lens material as well as cooling the handpiece. ... Exoeight Pooned J00!! Visual perception is one of the senses, consisting of the ability to detect light and interpret (see) it as the perception known as sight or naked eye vision. ...

Sensory system - Visual system - Eye
Optic disc - Retina - Cornea - Iris - Pupil - Lens - Macula - Sclera - Optic fovea - Blind spot - Vitreous humour - Aqueous humour - Choroid - Ciliary body - Conjunctiva - Angle structure - Tapetum lucidum


(See also sense) A sensory system is a part of the nervous system that consists of sensory receptors, neural pathways, and those parts of the brain responsible for processing the information. ... The visual system is what allows us to see. ... An eye is an organ that detects light. ... The optic disc is the point in the eye where the optic nerve enters the retina; it is not sensitive to light. ... Human eye cross-sectional view. ... The cornea is the curved, transparent layer that covers the front part of the eye and protects its inner structures. ... The human iris The iris is the grey-brown area. ... The human eye The pupil is the central transparent area (showing as black). ... Human eye cross-sectional view. ... The sclera is the white outer coating of the eye. ... The fovea, a part of the eye, is a spot located in the center of the macula. ... In anatomy, ones blind spot is the region of the retina where the optic nerve and blood vessels pass through to connect to the back of the eye. ... Vitreous humour is the clear substance that fills the part of the eyeball lying between the lens and the retina. ... The aqueous humour is the clear, watery fluid that fills the complex space in the front of the eye which is bounded at the front by the cornea and at the rear by the front surface or face of the vitreous humour. ... The choroid is a collection of blood vessels in the rear of the eye that oxygenate the retina; it is located beneath the sclera. ... There are two sets of ciliary muscles in the eye. ... The conjunctiva is a membrane that covers the sclera (white part of the eye) and lines the inside of the eyelids. ... This cats tapeta lucida make its eyes flash green in a photograph The tapetum lucidum (Latin: bright carpet) or tapetum is a reflecting layer behind the retina of the eye; it serves to reflect light back to the retina, increasing the quantity of light caught by the retina. ...

Sensory system - Visual system

Eye - Optic nerve - Optic chiasm - Optic tract - Lateral geniculate nucleus - Optic radiations - Visual cortex (See also sense) A sensory system is a part of the nervous system that consists of sensory receptors, neural pathways, and those parts of the brain responsible for processing the information. ... The visual system is what allows us to see. ... An eye is an organ that detects light. ... The optic nerve is the nerve that transmits visual information from the retina to the brain. ... Visual pathway with optic chiasm circled The optic chiasm (from the Greek χλαζειν to mark with an X, after the letter Χ chi) is the part of the brain where the optic nerves partially cross, those parts of the right eye which see things on the right side being connected to the... The optic tract is a part of the visual system in the brain. ... The lateral geniculate nucleus (LGN) of the thalamus is a part of the brain, which is the primary processor of visual information, received from the retina, in the CNS. Schematic diagram of the primate lateral geniculate nucleus. ... Right superior quadrantanopia. ... The visual cortex is the general term applied to both the primary visual cortex (also known as V1) and the visual association area (V2, V3, V4, V5). ...


  Results from FactBites:
 
NationMaster - Encyclopedia: Lens (vision) (1325 words)
The ciliary muscle is a muscle that affects zonules in the eye (fibers that suspend the lens in position during accommodation), enabling changes in lens shape for light focusing.
During the fetal stage, the development of the lens is aided by the hyaloid artery.
The aqueous humour is the clear, watery fluid that fills the complex space in the front of the eye which is bounded at the front by the cornea and at the rear by the front surface or face of the vitreous humour.
Refractive Lens Exchange at Stahl Vision, Dayton, Ohio. (1629 words)
Refractive Lens Exchange at Stahl Vision, Dayton, Ohio.
Refractive Lens Exchange (RLE) involves removing the natural lens of the eye that has lost its ability to focus at near and far, and replace it with an implant lens that allows clear vision for distance and near vision.
Refractive lens exchange is done at our ambulatory surgery center as an outpatient procedure that takes about thirty minutes—you go in for your surgery in the morning, and go home a couple of hours later.
  More results at FactBites »

 
 

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