Difference between revisions of "Eye"
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| − | + | The '''eye''' is the organ of sight. The eye enables creatures to perceive light in various ways, from simple lightness versus darkness, to full-fledged color vision. | |
| − | + | In the human, and most mammals, the eye consists of several structures. The cornea is a protective outer layer. The iris is an aperture through which light enters. The lens is controlled by muscles to focus the light on the cornea - which is where the receptors for light are located. | |
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| + | The cornea has many specialized nerve endings that are able to react to light and send their signals via the optic nerve to the brain for interpretation. There are receptors for subtle levels of light, which enable, at least, black and white vision in low-light environments. There are also receptors that repsondf to higher levels of light that can perceive color. | ||
| − | + | Typically eyes come in pairs, to allow binocular vision, which allows depth perception, but [[spider]]s (for example) have eight eyes, and [[scallop]]s may have several dozen. | |
== Diseases of the eye == | == Diseases of the eye == | ||
| + | [[Image:Eyeball.jpg|right|thumb|Doctors performing an eye surgery.]] | ||
The eye worm ''Loa loa'', a [[parasitism|parasitic]] [[nematode]] worm, inhabits the vitreous humour of the human eyeball in parts of Africa, and is often only detected when somebody sees the worm swimming across inside the eyeball. [http://www.paru.cas.cz/helminti/Nematoda/Loa_loa.gif] | The eye worm ''Loa loa'', a [[parasitism|parasitic]] [[nematode]] worm, inhabits the vitreous humour of the human eyeball in parts of Africa, and is often only detected when somebody sees the worm swimming across inside the eyeball. [http://www.paru.cas.cz/helminti/Nematoda/Loa_loa.gif] | ||
Revision as of 01:35, May 13, 2007
The eye is the organ of sight. The eye enables creatures to perceive light in various ways, from simple lightness versus darkness, to full-fledged color vision.
In the human, and most mammals, the eye consists of several structures. The cornea is a protective outer layer. The iris is an aperture through which light enters. The lens is controlled by muscles to focus the light on the cornea - which is where the receptors for light are located.
The cornea has many specialized nerve endings that are able to react to light and send their signals via the optic nerve to the brain for interpretation. There are receptors for subtle levels of light, which enable, at least, black and white vision in low-light environments. There are also receptors that repsondf to higher levels of light that can perceive color.
Typically eyes come in pairs, to allow binocular vision, which allows depth perception, but spiders (for example) have eight eyes, and scallops may have several dozen.
Diseases of the eye
The eye worm Loa loa, a parasitic nematode worm, inhabits the vitreous humour of the human eyeball in parts of Africa, and is often only detected when somebody sees the worm swimming across inside the eyeball. [1]
![[1]](http://www.paru.cas.cz/helminti/Nematoda/Loa_loa.gif){kind=link}
Evolution of the eye
Numerous, unrelated organisms possess eyes of varying degrees of complexity. Evolutionists allege that these all evolved independantly to meet a common need; this is discussed in some detail in Climbing Mount Improbable, by Richard Dawkins. [2]
Creationists commonly cite the necessary complexity of the eye, in order for it to offer even basic functionality, as clear evidence that it could not have arisen via an evolutionary process.
Eyes in the Bible
The word 'eye' appears over seven hundred times in the Bible.
And if any mischief follow, then thou shalt give life for life, Eye for eye, tooth for tooth, hand for hand, foot for foot, Burning for burning, wound for wound, stripe for stripe. Exodus 21:23-25
When Samson was captured by the Philistines, his eyes were put out. Judges 16:21
And if thy right eye offend thee, pluck it out, and cast it from thee: for it is profitable for thee that one of thy members should perish, and not that thy whole body should be cast into hell. Matthew 5:29