Term
Emmetropia
EMMA Don't need no |
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Definition
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Term
| With MYOPIA where are the parallel rays of light focused |
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Definition
| In front of the retina (accommodation at rest) |
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Term
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Definition
Too strong. Or the globe is too long
Nearsightedness |
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Term
| What kind of lens do you use to correct MYOPIA |
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Definition
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Term
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Definition
Axial (Globe size)
Ciliary Spasms (theory for general myopia)
Genetics and environment are leading theories |
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Term
| Where do the parallel rays of light for HYPEROPIA |
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Definition
| Behind the retina (Virtual focus) |
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Term
| The globe for HYPEROPIA is |
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Definition
Too short
Eye is too weak
Farsightedness |
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Term
| What kind of lens to correct HYPEROPIA |
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Definition
Plus lens
in effect you have strengthened the eye |
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Term
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Definition
Globe size too short for focusing power of the eye
Latent hyperopia (hyperopia is masked by accommodation)
Absolute hyperopia (Not masked by accommodation |
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Term
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Definition
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Term
| What are the categories of ASTIGMATISM |
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Definition
Simple myopic
Simple hyperopic
Compound myopic
Compound hyperopic
Mixed
Every RX falls into one of these 5 categories |
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Term
| How does one do SPHERICAL EQUIVALENT |
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Definition
Take HALF of the cyl and add it to the sph power algebraically
+2.00 +2.00 x 180 = +3.00 d.s
-3.00 +1.00 x 090 = -2.50 d.s
+2.00 -2.00 x 180 = +1.00 d.s
-1.00 +2.00 x 090 = plano ! |
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Term
| Give an example when SPHERICAL EQUIVALENT could be used |
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Definition
During an emergency ie military
Used frequently with contacts |
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Term
| What does ISOMETROPIA mean |
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Definition
Identical RX's between both eyes
Spheres OU
Sphere, cyl, axis OU
w/Prism OU
Bifocal adds OU |
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Term
| What does ANISOMETROPIA mean |
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Definition
When the same refractive error exists between both eyes, but with a significant variation in amount
OD -2.00 -0.50 X 090
OS -5.00 -1.00 X 135 |
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Term
| What does ANTIMETROPIA mean |
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Definition
When each eye has the opposite refractive error one myopic one hyperopic
OD +1.00 -0.75 x 180
OS -2.25 -0.75 x 180 |
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Term
| What does ANISEIKONIA mean |
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Definition
A difference in the retinal image size between the two eyes
Caused by the spectacle correction ANTI & ANISO
Inhibits fusion
Tremendous ASTHENOPIA |
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Term
| What are some signs of MYOPES |
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Definition
Difficulty night vision/distance vision
OK at near |
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Term
| What are some signs of HYPEROPES |
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Definition
Asthenopia (eye strain)
Difficulty with prolonged reading/near work. Can have distance problems with high hyperopia or with age
Astigmatism: Can have difficulties with near and distance. Accommodation may clear one meridian, but blur other. (tilt) |
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Term
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Definition
| Stimulate the sphincter & cause pupillary constriction, glaucoma |
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Term
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Definition
| Dilate the pupil & paralyze ciliary muscle. Atropine; homatropine; tropicamide |
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Term
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Definition
| Dilate pupil for improved intra-ocular view. Epinephrine, eucatropine |
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Term
| What is CONSENSUAL REFLEX |
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Definition
| Pupil of one eye should constrict when light is shone on other eye. If eye w/o light dilates - afferent pupillary defect |
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