abo exam Questions and AnswersRevised and Updated
the transparent, colorless mass of soft, gelatinous material which fills the eyeball behind
the lens: -ANSWER- vitreous humor
the index of refraction of the crystalline lens is: -ANSWER- 1.42
the cornea has an index of refraction of: -ANSWER- 1.37
the extra-ocular muscles are inserted into the sclera and serve to rotate the eye in all
possible directions. There are _______________ of these muscles in each eye. -
ANSWER- 6
the fibrous tunic is comprised of the: -ANSWER- sclera and cornea
fusion occurs: -ANSWER- in the brain
the aqueous fluid is continually being manufactured by: -ANSWER- the ciliary body
the ability of the eye to bring objects if varying distances to focus on the retina is known
as: -ANSWER- accommodation
when accommodation is at rest, rays of light from a distant source come to focus in front
of the retina. this condition is known as: -ANSWER- myopia
when accommodation is at rest, rays of light from a distant source come to focus behind
the retina. this condition is known as: -ANSWER- hyperopia
impulses are carried from the retina to the brain along the: -ANSWER- optic nerve
while reading, or performing other near vision tasks: -ANSWER- the pupils constrict,
the eyes converge, & the crystalline lens accommodates
that area of the retina capable if perceiving the greatest amount of details is: -
ANSWER- forvea centralis
the average cornea has a refractive power of approximately: -ANSWER- 43 diopters
that layer if the cornea which is highly regenerative is: -ANSWER- the epithelium
Night vision is chiefly a function of the: -ANSWER- rods
,A tendency of the visual axis to deviate inward when the eyes are in a position of the
rest is known as: -ANSWER- esophoria
A "farsighted" eye is one that is: -ANSWER- hyperopic
The term used to indicate "double vision" is: -ANSWER- diplopia
The condition in which the ability to accommodate for near vision ecomes inadequate
because of loss of elasticity of the crystalline lens is called: -ANSWER- presbyopia
When there is loss of vision without any apparent disease of the eye, it is known as: -
ANSWER- amblyopia
A refractive error in which the rays of light do not come to a single point of focus is
called: -ANSWER- astigmatism
The condition in which the crystalline lens of the eye gradually loses its transparency
with consequent loss of visual acuity is known as: -ANSWER- cataract
An ocular disease as its primary characteristic a sustained increase in intraocular
pressure. -ANSWER- glaucoma
The space between the back of the iris and the front of the lens which is filled with
aqueous is the: -ANSWER- posterior chamber
A tendency of one eye to deviate upward is: -ANSWER- hyperphoria
The photosensitive receptors of the retina which are responsible for sharp visual acuity
and color perception are the: -ANSWER- cones
The layer of the cornea which comprises ninety percent of its thickness is: -ANSWER-
the stroma
A condition in which the refractive error of one eye significantly differs from that of the
other and where both eyes have the same sign (i.e. both eyes are myopic or myperopic)
is known as: -ANSWER- anisometropia
The refractive error which results in two points of focus falling behind the retina is: -
ANSWER- compound hyperopic astigmatism
The refractive condition caused by a damaged cornea so that rays of light come to
many focal points on the retina is known as: -ANSWER- irregular astigmatism
When the optical centers of a pair of plus lenses are positioned narrower than the PD, it
produces prism base... -ANSWER- IN
,When the optical centers of a pair of minus lenses are positioned narrower than the PD,
it produces prism base... -ANSWER- OUT
When a patient looks through a plus lens above the optical center, it produces prism
base... -ANSWER- DOWN
When a patient looks through a minus lens below the optical center, it produces prism
base... -ANSWER- DOWN
How much prism is induced 5 mm away from the optical center of a +2.00 diopter lens?
-ANSWER- 1.0
How much prism is induced 10 mm away from the optical center of a -0.25 diopter lens?
-ANSWER- 0.25
How much prism is induced 2 mm away from the optical center of a +16.00 diopter
lens? -ANSWER- 3.2
came in with the optical centers positioned 61 mm apart. The work order indicates the
patient's PD measures 64 mm and the prescription calls fro a -3.00 spheres in each
eye. How much total prism is induced and in which direction is the base? -ANSWER-
0.9 BASE OUT
A patient's prescription calls for OD: +4.75 OS: +2.50. The optical centers of the finished
spectacles are found to be positioned 4 mm too wide. How much total prism is induced
and in which direction is the base? -ANSWER- 1.45 BASE OUT
the index of refraction is lowest in: -ANSWER- air
when parallel rays of light enter prism, the light is deviated: -ANSWER- toward the
base
one meter is equal to _______ inches. -ANSWER- 39.37
two meters equal ______ centimeters. -ANSWER- 200
the index of refraction of any given transparent material can be determined by: -
ANSWER- dividing the speed of light in air by the speed of light in the material.
the speed of light in air is approximately: -ANSWER- 186,000 miles per second
when the direction of light is deviated in the course of the passing from one transparent
medium to another it is known: -ANSWER- refraction
, light travels through a certain transparent medium at the rate of approximately 109,412
miles per sec. the index of refraction of that medium is: -ANSWER- 1.70
if a prism can displace an image one centimeter at a distance of one meter, it is said to
have a power of: -ANSWER- 1 prism diopter
the distance between the crest of two waves is called the: -ANSWER- wavelength
the focal length of a -5.00 diopter lens is: -ANSWER- -20 cm
decentering a plus lens upward will result in: -ANSWER- base up prism
the _________________ theory describes light as traveling through space in minute
bursts of energy. -ANSWER- corpuscular
if a converging lens has a focal length of +2 meters, its power is: -ANSWER- +0.50
diopters
visible light is part of the overall spectrum of radiant energy. although the range of
wavelengths of which are perceived as visible light can vary with the individual, it is
generally understood to lie between: -ANSWER- 390 and 750 nanometers
prentice's rule states that the amount of induced prism is equal to: -ANSWER- power
of the lens X the decentration in mm / 10
a pair of spectacles were ordered with a prescription of -2.00D in each eye and a PD of
63 mm. they were received from the lab with the optical centers set 66mm apart. how
much total prism was induced and in which direction is the base? -ANSWER- 0.6
prism diopters base in
a pair of +4.00 spectacle lenses were ordered from the laboratory with a PD of 59 mm.
when these lenses were verified, it was determined that the optical centers were
positioned 4mm too wide. how much prism was induced in each eye and in which
direction is the base? -ANSWER- 0.8 prism diopters base out
a diverging lens produces a _______ image. -ANSWER- virtual
the focal length of a +1.00 diopter lens is: -ANSWER- +100 cm
rays emanating from a point source of light are said to be: -ANSWER- diverging
if the pad arms are lengthened, this adjustment will: -ANSWER- push the front out
more
the plier best used for adjustment of rocking pads is: -ANSWER- half round
the transparent, colorless mass of soft, gelatinous material which fills the eyeball behind
the lens: -ANSWER- vitreous humor
the index of refraction of the crystalline lens is: -ANSWER- 1.42
the cornea has an index of refraction of: -ANSWER- 1.37
the extra-ocular muscles are inserted into the sclera and serve to rotate the eye in all
possible directions. There are _______________ of these muscles in each eye. -
ANSWER- 6
the fibrous tunic is comprised of the: -ANSWER- sclera and cornea
fusion occurs: -ANSWER- in the brain
the aqueous fluid is continually being manufactured by: -ANSWER- the ciliary body
the ability of the eye to bring objects if varying distances to focus on the retina is known
as: -ANSWER- accommodation
when accommodation is at rest, rays of light from a distant source come to focus in front
of the retina. this condition is known as: -ANSWER- myopia
when accommodation is at rest, rays of light from a distant source come to focus behind
the retina. this condition is known as: -ANSWER- hyperopia
impulses are carried from the retina to the brain along the: -ANSWER- optic nerve
while reading, or performing other near vision tasks: -ANSWER- the pupils constrict,
the eyes converge, & the crystalline lens accommodates
that area of the retina capable if perceiving the greatest amount of details is: -
ANSWER- forvea centralis
the average cornea has a refractive power of approximately: -ANSWER- 43 diopters
that layer if the cornea which is highly regenerative is: -ANSWER- the epithelium
Night vision is chiefly a function of the: -ANSWER- rods
,A tendency of the visual axis to deviate inward when the eyes are in a position of the
rest is known as: -ANSWER- esophoria
A "farsighted" eye is one that is: -ANSWER- hyperopic
The term used to indicate "double vision" is: -ANSWER- diplopia
The condition in which the ability to accommodate for near vision ecomes inadequate
because of loss of elasticity of the crystalline lens is called: -ANSWER- presbyopia
When there is loss of vision without any apparent disease of the eye, it is known as: -
ANSWER- amblyopia
A refractive error in which the rays of light do not come to a single point of focus is
called: -ANSWER- astigmatism
The condition in which the crystalline lens of the eye gradually loses its transparency
with consequent loss of visual acuity is known as: -ANSWER- cataract
An ocular disease as its primary characteristic a sustained increase in intraocular
pressure. -ANSWER- glaucoma
The space between the back of the iris and the front of the lens which is filled with
aqueous is the: -ANSWER- posterior chamber
A tendency of one eye to deviate upward is: -ANSWER- hyperphoria
The photosensitive receptors of the retina which are responsible for sharp visual acuity
and color perception are the: -ANSWER- cones
The layer of the cornea which comprises ninety percent of its thickness is: -ANSWER-
the stroma
A condition in which the refractive error of one eye significantly differs from that of the
other and where both eyes have the same sign (i.e. both eyes are myopic or myperopic)
is known as: -ANSWER- anisometropia
The refractive error which results in two points of focus falling behind the retina is: -
ANSWER- compound hyperopic astigmatism
The refractive condition caused by a damaged cornea so that rays of light come to
many focal points on the retina is known as: -ANSWER- irregular astigmatism
When the optical centers of a pair of plus lenses are positioned narrower than the PD, it
produces prism base... -ANSWER- IN
,When the optical centers of a pair of minus lenses are positioned narrower than the PD,
it produces prism base... -ANSWER- OUT
When a patient looks through a plus lens above the optical center, it produces prism
base... -ANSWER- DOWN
When a patient looks through a minus lens below the optical center, it produces prism
base... -ANSWER- DOWN
How much prism is induced 5 mm away from the optical center of a +2.00 diopter lens?
-ANSWER- 1.0
How much prism is induced 10 mm away from the optical center of a -0.25 diopter lens?
-ANSWER- 0.25
How much prism is induced 2 mm away from the optical center of a +16.00 diopter
lens? -ANSWER- 3.2
came in with the optical centers positioned 61 mm apart. The work order indicates the
patient's PD measures 64 mm and the prescription calls fro a -3.00 spheres in each
eye. How much total prism is induced and in which direction is the base? -ANSWER-
0.9 BASE OUT
A patient's prescription calls for OD: +4.75 OS: +2.50. The optical centers of the finished
spectacles are found to be positioned 4 mm too wide. How much total prism is induced
and in which direction is the base? -ANSWER- 1.45 BASE OUT
the index of refraction is lowest in: -ANSWER- air
when parallel rays of light enter prism, the light is deviated: -ANSWER- toward the
base
one meter is equal to _______ inches. -ANSWER- 39.37
two meters equal ______ centimeters. -ANSWER- 200
the index of refraction of any given transparent material can be determined by: -
ANSWER- dividing the speed of light in air by the speed of light in the material.
the speed of light in air is approximately: -ANSWER- 186,000 miles per second
when the direction of light is deviated in the course of the passing from one transparent
medium to another it is known: -ANSWER- refraction
, light travels through a certain transparent medium at the rate of approximately 109,412
miles per sec. the index of refraction of that medium is: -ANSWER- 1.70
if a prism can displace an image one centimeter at a distance of one meter, it is said to
have a power of: -ANSWER- 1 prism diopter
the distance between the crest of two waves is called the: -ANSWER- wavelength
the focal length of a -5.00 diopter lens is: -ANSWER- -20 cm
decentering a plus lens upward will result in: -ANSWER- base up prism
the _________________ theory describes light as traveling through space in minute
bursts of energy. -ANSWER- corpuscular
if a converging lens has a focal length of +2 meters, its power is: -ANSWER- +0.50
diopters
visible light is part of the overall spectrum of radiant energy. although the range of
wavelengths of which are perceived as visible light can vary with the individual, it is
generally understood to lie between: -ANSWER- 390 and 750 nanometers
prentice's rule states that the amount of induced prism is equal to: -ANSWER- power
of the lens X the decentration in mm / 10
a pair of spectacles were ordered with a prescription of -2.00D in each eye and a PD of
63 mm. they were received from the lab with the optical centers set 66mm apart. how
much total prism was induced and in which direction is the base? -ANSWER- 0.6
prism diopters base in
a pair of +4.00 spectacle lenses were ordered from the laboratory with a PD of 59 mm.
when these lenses were verified, it was determined that the optical centers were
positioned 4mm too wide. how much prism was induced in each eye and in which
direction is the base? -ANSWER- 0.8 prism diopters base out
a diverging lens produces a _______ image. -ANSWER- virtual
the focal length of a +1.00 diopter lens is: -ANSWER- +100 cm
rays emanating from a point source of light are said to be: -ANSWER- diverging
if the pad arms are lengthened, this adjustment will: -ANSWER- push the front out
more
the plier best used for adjustment of rocking pads is: -ANSWER- half round
