Difference between revisions of Eyeballs
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Viceroy Sam (talk | contribs) (Move in Ciliary muscle, add bolding.) |
Viceroy Sam (talk | contribs) (Move Cornea) |
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= Parts of the eye = | = Parts of the eye = | ||
* '''Sclera''' - The white of the eye | * '''Sclera''' - The white of the eye | ||
* '''Cornea''' | * '''Cornea''' is the clear outer layer of the eye through which you can see the [[Iris]] and [[Pupil]]. It has an [[Index of Refraction]] of 1.376<ref name="Scale Model of Eye">{{Cite web |title=Scale Model of Eye |url=http://hyperphysics.phy-astr.gsu.edu/hbase/vision/eyescal.html |last=Nave |first=R |date=2020-05-25 |website=HyperPhysics}}</ref>, and a curved outer surface, contributing to the [[refractive state]] of the eye. The Cornea provides about 80% of the eye's total refracting power. If you have [[LASIK]] or [[PRK]] surgery it thins the cornea to change your refractive state. | ||
* '''Aqueous humor''' - the fluid supporting the cornea | * '''Aqueous humor''' - the fluid supporting the cornea | ||
* '''Pupil''' - the hole where light enters the eye | * '''Pupil''' - the hole where light enters the eye | ||
* '''Iris''' - the Iris is the colored part of the eyeball that contains the muscles that control the opening size of the pupil. | * '''Iris''' - the Iris is the colored part of the eyeball that contains the muscles that control the opening size of the pupil. | ||
* '''Ciliary muscle''' | * '''Ciliary muscle''' is a ring of muscle fibers in the eye that control the tendons supporting the natural [[lens]] of the eye, and controls the flow of [[aqueous humor]] behind the [[cornea]]. The Ciliary muscle is controlled by the Ciliary ganglion, which is a complex intersection of several nerve systems. The action of the ciliary muscle is the primary source of [[accommodation]] and [[ciliary spasm]] which causes [[pseudomyopia]]. | ||
* '''Lens''' - The part that changes the focus distance of the eye | * '''Lens''' - The part that changes the focus distance of the eye | ||
* '''Vitreous humor''' - the gel filling the eye (this is where [[floaters]] usually form) | * '''Vitreous humor''' - the gel filling the eye (this is where [[floaters]] usually form) | ||
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= Axial Length = | = Axial Length = | ||
The primary cause of differences in [[refractive state]] is the length of the eye, referred to as axial length, relative to the focusing power. Long eyeballs are associated with myopia, as the natural lens of the eye focuses light too far forward of the retina. | The primary cause of differences in [[refractive state]] is the length of the eye, referred to as axial length, relative to the focusing power. Long eyeballs are associated with myopia, as the natural lens of the eye focuses light too far forward of the retina. | ||
==References== | |||
{{reflist}} | |||
Revision as of 13:45, 8 June 2020
Parts of the eye
- Sclera - The white of the eye
- Cornea is the clear outer layer of the eye through which you can see the Iris and Pupil. It has an Index of Refraction of 1.376[1], and a curved outer surface, contributing to the refractive state of the eye. The Cornea provides about 80% of the eye's total refracting power. If you have LASIK or PRK surgery it thins the cornea to change your refractive state.
- Aqueous humor - the fluid supporting the cornea
- Pupil - the hole where light enters the eye
- Iris - the Iris is the colored part of the eyeball that contains the muscles that control the opening size of the pupil.
- Ciliary muscle is a ring of muscle fibers in the eye that control the tendons supporting the natural lens of the eye, and controls the flow of aqueous humor behind the cornea. The Ciliary muscle is controlled by the Ciliary ganglion, which is a complex intersection of several nerve systems. The action of the ciliary muscle is the primary source of accommodation and ciliary spasm which causes pseudomyopia.
- Lens - The part that changes the focus distance of the eye
- Vitreous humor - the gel filling the eye (this is where floaters usually form)
- Rods and cones - the sensory cells of the eye that see light intensity and color
- Retina - the tissue that supports the rods and cones.
Axial Length
The primary cause of differences in refractive state is the length of the eye, referred to as axial length, relative to the focusing power. Long eyeballs are associated with myopia, as the natural lens of the eye focuses light too far forward of the retina.
References
- ↑ Nave, R (2020-05-25). "Scale Model of Eye". HyperPhysics.Page Module:Citation/CS1/styles.css has no content.