Term
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Definition
| secretion by ciliary body--absorption cornea-iris angle--canal of Schlemm |
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Term
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Definition
eye too long or lens too strong
image focused in front of retina
biconcave lens (diverging) correction |
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Term
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Definition
Eye too short or lens too weak
image focused behind retina
biconvex lens (converging) correction |
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Term
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Definition
Eye too short or lens too weak
image focused behind retina
biconvex lens (converging) correction |
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Term
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Definition
curvature of cornea is abnormal
refractive power in one plane exceeds refractive power in another
blurriness either up close or from a distance |
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Term
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Definition
lens losses its flexibility with age
greater difficulty seen up close objects (accommodation) |
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Term
| autonomic control of accommodation |
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Definition
• controlled by parasympathetic fibers of CN III: causes contraction of ciliary musclelens become more convex
• eyes converge
• pupils constrict (ACh of CN III acts on dilator muscles), whereas dilation is controlled by sympathetic (NE on dilator) |
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Term
| pupillary adjustment to light intensity |
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Definition
• direct and consensual
• CN II (optic): afferent (sensory) limb
• CN III (oculomotor): efferent (motor) limb--parasympathetic |
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Term
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Definition
sensitivity to light: low threshold; night vision
Acuity: low; not present on fovea
Dark adaptation: adapt late
Color vision: no |
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Term
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Definition
Light: high threshold; day vision
Acuity: high; present on fovea
Dark adaptation: early
Color vision: yes |
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