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32 Cards in this Set
- Front
- Back
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What supplies the majority of cues for orientation?
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Visual ~90%
Vestibular & Proprio ~10% |
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Visual light spectrum?
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380 (Violet) - 760 (Red) millimicrons
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Two wavelengths that can damage eyes?
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Ultraviolet - (Tanning Booth) damage the Cornea
Infrared - Retina |
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What are the two types of photosensative cells in the retina?
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Rods & Cones
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Imbalance of strength (ie hypoxia or fatigue) effects what muscles and causes what?
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Ciliary Muscles
Double Vision |
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Cornea
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* "Lens Cap" - Transparent Outer layer of cells
* Refractive Quality (Focusing) |
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Lens does what?
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Refracts light rays onto the Retina
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Lens is ___ & ____?
What muscle changes the lens' shape? |
Soft and Moldable
Ciliary muscles |
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Ciliary muscles:
Contract= ________ Relax=________ |
Fat - More refraction
thin - less refraction |
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Reaction Times:
Recognition __ Perceive Collision CRS __ Decide Turn __ Muscle Rxn __ A/C Lag time __ |
.1
1.0 5.0 4.0 2.5 |
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Whats happens to the lens with age?
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Stiffens and becomes opaque (Cataracts0
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Iris
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"Aperture" Opening
* Changes to allow different amounts of light in |
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What happens when there is excessive light?
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Iris - Small
Increases the DEPTH of FIELD |
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What is depth of field?
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the nearest and farthest distances from the lens within which everything is in focus
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What happens in low light?
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Iris - Large
Decreases the Depth of Field |
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Retina
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"Film"
Houses the photosensitive cells |
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Optic Nerve
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Bundle of Nerves
Physical Blind Spot |
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CONES
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Photopic Vision
* Bright Light & Color * Clarity * Concentrated in the Fovea (Part of the Macula) |
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Fovea = ___ Vision
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CENTRAL
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Rod Cells
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Scotopic Vision
* Night Vision * Low light & not Colors |
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Rod Cells = ___ Vision & _____ = Scotopic
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Peripheral & Orientation
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Rods are how many more times sensitive to light than cones?
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10,000
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Low light causes what to our vision?
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Blind spot due to cones cells not working in low light
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Night blind spot is where?
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Directly in the middle of our vision, but is overcome slightly be having to eyes and a good scan
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The Retina is a direct ext. of the the ___ & is susceptible to what?
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Brain
Hypoxia, Alc, Meds |
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The lens can focus on a ___ object and a __ object?
What is this property called? |
Near and Far
Accommodation - Refractive powers of the lens changes for continuous focus |
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Fog and Haze does what?
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Poor visual Acuity
Decrease Contrast creates perceptual illusions |
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Each color refracts differently, which color refracts less? What does that lead to (why its not used in the cockpit)?
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Red
Unfocused perception |
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What affects acuity?
What is acuity? |
Lens
Sharpness, clarity of vision |
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Myopia
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nearsightedness
M/C FP is in front of retina |
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Astigmatism
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Type of Farsightedness
Age related - Lens stiffens & is unable to ACCOMMODATE effectively. FP behind retina |
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Hyperopia
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Fairsightedness
FP behind retina |
