Eye
From CreationWiki, the encyclopedia of creation science
Contents |
Evolution
Even Charles Darwin recognized that the eye was imminently complex and admitted that attempting to explain its origin through natural selection seemed absurd.
| “ | To suppose that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree. [1] | ” |
Nevertheless, Darwin believed this absurdity was merely illusory, and preceded to provide an explanation for its evolution in his book, The Origin of Species.[2]
Components
Cornea
The cornea is the transparent convex tissue at the front of the eye (figure at right) that serves two specialized functions. First, it forms, with the sclera, a protective physical barrier that shields the inner eye from the external environment. Equally important is its ability to protect itself from various types of damage, ranging from physical trauma and biochemical injury to infections by myriad pathogenic organisms, to the deleterious effects of long-term exposure to light itself. In protecting itself, the cornea also safeguards many underlying ocular structures from similar damage. Second, the cornea serves as the main refractive element of the visual system, directing incoming light onto the crystalline lens, which focuses it onto the retina. Refraction depends on the cornea acquiring transparency during embryonic development and maintaining it throughout adult life.[3]
Other
- Choroid: A layer of blood vessels that feeds the retina.
- Cornea: The clear outer part of the eye's focusing system located at the front of the eye.
- Eyelid: The skin-covered structure that protects the front of the eye; limits light entering the eye; spreads tears over the cornea.
- Fovea: The center of the macula; gives the sharpest vision.
- Iris: The colored part of the eye; regulates the amount of light entering the eye.
- Lens: The clear part of the eye behind the iris that helps to focus light on the retina; allows the eye to focus on both far and near objects.
- Macula: The small, sensitive area of the retina that gives central vision; contains the fovea.
- Optic nerve: The bundle of more than 1 million nerve fibers that carry visual messages from the retina to the brain.
- Pupil: The opening at the center of the iris. The iris adjusts the size of the pupil and controls the amount of light that can enter the eye.
- Retina: The light-sensitive layer of tissue that lines the inside of the eye and sends visual messages through the optic nerve to the brain.
- Sclera: The tough white outer coat of the eye.
- Vitreous humor: The clear gel filling the inside of the eye.[4]
References
- ↑ The Origin of Species by Charles Darwin. J.M. Dent & Sons Ltd, London, 1971, p. 167.
- ↑ * Darwin vs. the Eye by Tom Wagner. Creation ex nihilo 16(4):10–13. September 1994
- ↑ Report of the Corneal Diseases Panel by the National Eye Institute.
- ↑ Wild About Healthy Vision by the National Eye Institute.
External links
- Miracle of the Eye by Harun Yahya
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 A section of retina shows the thinner rods and wider cones. |
 Retina photoreceptors |
 Retinal photoreceptor |
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