6 PRIMER (MEASUREMENTS) Flashcards
GULLSTRAND'S SCHEMATIC EYE INDEX OF REFRACTION: * CORNEA * AQEOUS HUMOR * CRYSTALLINE LENS (cortex) (nucleus) * VITREOUS HUMOR
- CORNEA 1.376
- AQEOUS HUMOR 1.336
- CRYSTALLINE LENS
1. 386 (cortex)
1. 406 (nucleus) - VITREOUS HUMOR 1.336
Higher index of refraction
- slower speed of light
- faster speed of light
slower speed of light
Higher index of refraction
- lesser bending
- greater bending
greater bending
Lower index of refraction
- slower speed of light
- faster speed of light
faster speed of light
Lower index of refraction
- lesser bending
- greater bending
lesser bending
RADIUS OF CURVATURE
CORNEA
front surface: \_\_\_\_\_mm
back surface: \_\_\_\_\_mm
LENS
front surface: \_\_\_\_\_mm
back surface: \_\_\_\_\_mm
RADIUS OF CURVATURE
CORNEA
front surface: 7.7mm
back surface: 6.8mm
LENS
front surface: 10.0mm
back surface: 6.0mm
Shorter radius of curvature:
- flatter
- steeper
steeper
Shorter radius of curvature:
- lesser power
- greater power
greater power
Shorter radius of curvature:
- lesser bending
- greater bending
greater bending
Longer radius of curvature:
- flatter
- steeper
flatter
Shorter radius of curvature:
- lesser power
- greater power
lesser power
Shorter radius of curvature:
- lesser bending
- greater bending
lesser bending
REFRACTIVE POWER
CORNEA: ____ D
LENS (UNACCOMMODATED): ____ D
COMPLETE EYE (UNACCOMMODATED: ____ D
REFRACTIVE POWER
CORNEA: 43.05 D
LENS (UNACCOMMODATED): 19.11 D
COMPLETE EYE (UNACCOMMODATED: 58.64 D
Higher refractive power
- lesser bending
- greater bending
greater bending
Lesser refractive power
- lesser bending
- greater bending
lesser bending
2/3 of refraction of the eye
- Cornea
- Tear film
- Crystalline Lens
Cornea
Power ranges from 36.00-50.00 D (average: 43.00 D)
- Cornea
- Tear film
- Crystalline Lens
Cornea
index: 1.376
- Cornea
- Tear film
- Crystalline Lens
Cornea
Where cornea owes its clear optical
- Cornea
- Tear film
- Crystalline Lens
Tear film
First surface where light is refracted followed by the cornea
- Cornea
- Tear film
- Crystalline Lens
Tear film
Steeper curvature will result to:
- lower surface power
- higher surface power
higher surface power
CL w/ shorter RC
- flatter tear layer radius
- steep tear layer radius
increase corneal power posterior
steep tear layer radius
CL w/ shorter RC
- decrease corneal power posterior
- increase corneal power posterior
increase corneal power posterior
Flatter curvature will result to
- lower surface power
- higher surface power
lower surface power
Cl.w/ longer RC
- flat tear layer radius
- steep tear layer radius
flat tear layer radius
Cl.w/ longer RC
- decrease corneal power posterior principal
- increase corneal power posterior principal
decrease corneal power posterior principal
1/3 of refraction of the eye
- Cornea
- Tear film
- Crystalline Lens
Crystalline Lens
Important structure for ACCOMMODATION
- Cornea
- Tear film
- Crystalline Lens
Crystalline Lens
Process by which the crystalline lens varies its focal length in response to changes in vergence (direction) of incident light
- Accommodation
- Binocular Fusion
Accommodation
Dioptric adjustment of the eye to attain maximum sharpness of retinal imagery for an object of regard
- Accommodation
- Binocular Fusion
Accommodation
primary stimulus for accommodation
- blur
- near target
blur
other stimulus for accommodaiton
- blur
- near target
near target
If the accommodation is Insufficient, object will still fall behind the retina, the distance between the focus to the retina is termed as __________
- LAG OF ACCOMMODATION
- LEAD OF ACCOMMODATION
LAG OF ACCOMMODATION
the most common form of color blindness results in a confusion of ____________
- red and blue shades
- red and green shades
red and green shades
is about having a sense of direction while moving around an environment
- Binocular fusion
- Spacial Orientation
Spacial Orientation
__________, in his classic thesis, described an island of vision in the sea of darkness
- Traquair
- Point of fixation
- Blindspot
Traquair
The (1) _______ represents the perceived field of vision, and the (2) _________ is the surrounding areas that are not seen
- sea of darkness
- island
(1) island
(2) sea of darkness
highest peak of the Island
- Traquair
- Point of fixation
- Blindspot
Point of fixation
bottomless pit
- Traquair
- Point of fixation
- Blindspot
Blindspot
The process of producing a single image from the two disparate monocular images is called ________
- binocular fusion
- depth perception
binocular fusion
Law of Retinal/Sensory Correspondence
- binocular fusion
- depth perception
binocular fusion
permits the perception a single clear image
- binocular fusion
- depth perception
binocular fusion
where one eye deviates from the normal position and/or is paralyzed
- amblyopia
- strabismus
strabismus
strabimus at birth, if uncorrected, may result to _______
- amblyopia
- strabismus
amblyopia
approximate distance of an object
- binocular fusion
- depth perception
depth perception
Some of these cues can be processed by just one eye, which is why they are referred to as ______
- monocular cues
- relative size
monocular cues
If two objects are roughly the same size, the object that looks the largest will be judged as being the closest to the observer
- monocular cues
- relative size
relative size
As you are moving, objects that are closer seem to zoom by faster than do objects in the distance
- motion parallax
- aerial perspective
motion parallax
Objects that are farther away seem to be blurred or slightly hazy.
- motion parallax
- aerial perspective
aerial perspective
Parallel lines appears to meet as they travel into the distance.
- Linear Perspective
- Overlap (or Inter position)
Linear Perspective
When one object overlaps another, the object that is partially obscured is perceived as being farther away.
- Linear Perspective
- Overlap (or Inter position)
Overlap (or Inter position)
can cause permanent blindness
- Vitamin A deficiency
- Vitamin B deficiency
- Vitamin C deficiency
- Vitamin D deficiency
Vitamin A deficiency
is an inherited disorder in which there is a gradual and progressive failure to maintain the receptor cells
- Retinitis pigmentosa
- Macular Degeneration
Retinitis pigmentosa
A symptom of this condition is ‘night blindness’ and loss of peripheral vision.
- Retinitis pigmentosa
- Macular Degeneration
Retinitis pigmentosa
the cones receptors function normally and central vision remains intact
- Retinitis pigmentosa
- Macular Degeneration
Retinitis pigmentosa
The leading cause of blindness in the elderly.
- Retinitis pigmentosa
- Macular Degeneration
Macular Degeneration
The _________ involves intraocular proliferation of cells in the macular area, the fovea and the immediately surrounding retinal areas
- dry form of macular degeneration
- wet form of macular degeneration
dry form of macular degeneration
In the _________, the capillaries of the choroid coat invade the macular area and destroy receptor cells and neurons.
- dry form of macular degeneration
- wet form of macular degeneration
wet form of macular degeneration
When the neural retina is torn away from the retinal pigment epithelium,
- Retinal detachment
- Diabetic Retinopathy
Retinal detachment
supplies glucose and essentiai ions to the neural retina, helps support the photoreceptor cell outer segment, removes outer segment disks shed by the receptor cells, and converts retinol and stores vitamin A for photopigment resynthesis
- neural retina
- retinal pigment epithelium
retinal pigment epithelium
Involves microaneurysms and pretunctate hemorrhages in the retina
- retinal detachment
- diabetic retinopathy
diabetic retinopathy
The tiny swollen blood vessels and/or bleeding in the underlying choroid, coat damage the receptor cells and retinal neurons and result in blindness in the regions affected.
- retinal detachment
- diabetic retinopathy
diabetic retinopathy
