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46 Cards in this Set
- Front
- Back
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What parts of the eye cause refraction? |
The cornea and the lens |
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What is the scientific term for "normal" vision? |
Emmetropia |
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What is myopia? |
The ability to focus on objects close to you, but not distant from you |
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What is the scientific term for being "far-sighted"? |
Hyperopia |
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What is astigmatism? |
When the cornea is not round, but an oval shape |
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What are the effects of astigmatism? |
Instead of one focal point, there are multiple focal points |
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What are tears made up of? |
An oily layer, an aqueous layer, and a mucus layer |
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Where is the meibomian gland, and what does it produce? |
In the eye lid and produces the oily layer |
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What is the purpose of the oily layer? |
To inhibit evaporation |
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What gland produces the aqueous layer and where is it located? |
The lacrimal gland and it is located above the eyelid |
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What is the purpose of the aqueous layer? |
It supplies oxygen and nutrients to the cornea |
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What produces the mucus layer, and where is it located? |
Goblet cells produce the mucus layer and it is located in the conjuctiva |
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What is the purpose of the mucus layer? |
To ensure even distribution of tear film across the eye |
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What does the bony orbit do? |
It supports the globe within the orbital fat |
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What is the conjuctiva? |
A thin membrane that lines the surface of the globe and eye lids |
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What are the two types of conjuctiva and where are they located |
Bulbar conjuctiva on the globe itself and Palpebral conjuctiva on the eyelids |
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What is the fornix? |
The area where both types of conjuctiva meet |
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How many muscles are attached to the eye? |
3 pairs, or 6 muscles total |
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What are the two names of the muscles? |
The rectus and oblique muscles |
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What is the scientific term for a "lazy eye"? |
Strabismus |
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What are the two types of strabismus? |
Esotopia and Exotopia |
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What is the white tissue surrounding the globe of the eye? |
The sclera |
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Where is the cornea located? |
It is the outermost portion of the front of the eye |
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How much is the cornea responsible for refractive power in the eye? |
70% |
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How many layers does the cornea have? |
5 layers |
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What are the names of the top, middle, and bottom layers of the cornea? |
Epithelium, stroma, and endothelium |
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Where is the anterior chamber located? |
Between the cornea and iris |
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What is the anterior chamber filled with? |
Aqueous Humor |
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Where is aqueous humor produced? |
The ciliary body |
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What is the travel path of aqueous humor? |
Goes from the ciliary body, around the iris to the anterior chamber, gets emptied in the the filtration angle through the trabecular meshwork, and escapes outside the globe through Schlemm's Canal |
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What does the uveal tract consist of? |
Iris, ciliary body, and choroid |
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What is the iris? |
Colored aperture of tissue |
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What does the iris do? |
It varies the size of the pupil based on the amount of light directed at it |
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What are the two muscles of the iris? |
The dilator and the sphincter |
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What is the ciliary body? |
A radial band of tissue behind the iris |
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What muscle does the ciliary body contain? |
The ciliary muscle which supports the lens |
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What does the choroid do? |
It provides blood supply for the outermost layers of the retina |
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Where does the blood supply come from? |
The posterior ciliary artery |
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Where is the lens? |
Immediately behind the iris |
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How much refractive power does the lens provide? |
30% |
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What is the lens capsule? |
The clear elastic capsule the lens is suspended in |
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What is the name of the strands attaching the lens capsule to the ciliary body? |
Zonules of Zinn |
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What is the Vitreous? |
A clear jelly-like substance between the retina and the front components of the eye |
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What is the purpose of the vitreous? |
To support retinal position/placement |
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What are floaters? |
Particles that have broken off the vitreous, casting shadows on the retina |
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Where do the visual pathways go? |
To the visual cortex of the brain where they are "merged" |
