ABO Exam Study Guide 2026 with all Correct & 100%
Verified Answers |Actual Complete Update |Already
Graded A+
When discussing thick lenses, the factors which are considered in computing the lens power are
✔Correct Answer-front curve, back curve, thickness, and index
Which crown glass bifocal type will have the least chromatic aberration? ✔Correct Answer-A
"one piece" lens
Toric transposition shows ✔Correct Answer-power in principal meridians
Increasing the diameter of a minus power lens always increases its ✔Correct Answer-Weight
The optical center of a round segment is located ✔Correct Answer-in the geometric center of
the segment
the base curve of any multifocal lens is found on the surface containing the ✔Correct Answer-
segment
Normal slab-off (bicentric grind) is ground on the lens whose vertical meridian has the
✔Correct Answer-least plus power
the refractive error indicated by the Rx +1.75 -2.75 x 090 is: ✔Correct Answer-mixed
astigmatism
optical cross: +1.75 on 90 meridian, +1.75 -2.75 = 1.00 on 180 meridian
60-1.75 = 58.25
60+1.00 = 61
one is under 60 and one is over 60
Tempering a lens by heat treating results in a lens being: ✔Correct Answer-more resistant to
impact
A slab off lens is for the correction of ✔Correct Answer-excessive prism imbalance at the
reading level
Chem tempering makes a glass lens more impact resistant by placing the lens in a potassium
nitrate bath. The lens undergoes a process known as: ✔Correct Answer-Ion Exchange
Which wavelengths of light have been indicated as possible contributors to the onset of
cataracts? ✔Correct Answer-350-400
,UV wavelength
When the lenses are laid out and marked for cutting and edging, the lenses are usually
decentered so as to correspond to the patient's pupillary distance after lenses are inserted. This
is done for what reason? ✔Correct Answer-To avoid unwanted prism
If the identical bifocal prescription were made up in glass, (all parameters alike), which lens style
would be the heaviest? ✔Correct Answer-Executive
Light falling on the front surface of a spectacle lens is ✔Correct Answer-partially reflected,
partially absorbed, and the remainder refracted
a concave mirror can focus what kind of light on what kind of image? ✔Correct Answer-
Parallel incident rays forming a real image
White light is broken into its component colors when it is: ✔Correct Answer-Diffracted OR
Refracted
To the viewer, the image seen in a plane mirror appears to be: ✔Correct Answer-As far behind
the mirror as the object is in front of it
Rank the velocity of light in the following mediums: Air, Polycarbonate, Water, Flint Glass
✔Correct Answer-Flint Glass (181), Polycarbonate (194), Water (225), Air (300)
A lens dispersing white light into is component colors is an example of ✔Correct Answer-
Chromatic Aberration
The optical center of a lens is ✔Correct Answer-a lens location of zero deviation of the optical
axis
Light rays passing through a prism are deviated in what direction? ✔Correct Answer-toward
the base
Light travels outward in all directions from its source. The best explanation of this is that light
takes the form of: ✔Correct Answer-Wave fronts
The distance between the crest of one wave and the crest of the next one is called: ✔Correct
Answer-Wavelength
The interpretation of the range of wavelengths of visible light varies but is generally accepted as
lying between: ✔Correct Answer-400-700 nm
The breaking up of white light into its component colors by a lens or prism is called ✔Correct
Answer-dispersion
, The color in white light that is refracted the most after passing through a refracting test medium
is ✔Correct Answer-Violet
The reflection of light from a surface is most influenced by ✔Correct Answer-The regularity of
the surface, meaning the smoothness and texture
Light rays originating at a distant point source are described as being ✔Correct Answer-
Parallel
Which rays all lie in the same plane? ✔Correct Answer-Incident, reflected, normal
The bending of a ray of light when it goes from one medium to another is called ✔Correct
Answer-Refraction
A ray of light, passing from a dense to a less dense medium is bent ✔Correct Answer-away
from the normal
The concept or use of the term "normal" is that it is an imaginary line that is ✔Correct
Answer-perpendicular to the medium's surface at the point of incidence of the ray
A correct statement regarding the law of refraction (Snell's law) is that ✔Correct Answer-light
bends toward the normal when it enters a medium denser than the one in which it was
traveling
Any bundle of rays passing through a converging lens is made ✔Correct Answer-more
converging
The ray that can pass through a lens without being refracted is called ✔Correct Answer-The
axial ray
The angle of incidence, for which the angle of refraction is 90 degrees is called the ✔Correct
Answer-critical angle
When parallel incoming rays strike a convex mirror, the reflected rays ✔Correct Answer-seem
to originate from behind the mirror
A ray entering a less dense medium, striking the interface at an angle greater than the critical
angle will be ✔Correct Answer-Totally reflected internally
The image formed at the secondary focal point of a converging lens is ✔Correct Answer-a
virtual image
the image formed in the eye is ✔Correct Answer-real, inverted, and smaller
Verified Answers |Actual Complete Update |Already
Graded A+
When discussing thick lenses, the factors which are considered in computing the lens power are
✔Correct Answer-front curve, back curve, thickness, and index
Which crown glass bifocal type will have the least chromatic aberration? ✔Correct Answer-A
"one piece" lens
Toric transposition shows ✔Correct Answer-power in principal meridians
Increasing the diameter of a minus power lens always increases its ✔Correct Answer-Weight
The optical center of a round segment is located ✔Correct Answer-in the geometric center of
the segment
the base curve of any multifocal lens is found on the surface containing the ✔Correct Answer-
segment
Normal slab-off (bicentric grind) is ground on the lens whose vertical meridian has the
✔Correct Answer-least plus power
the refractive error indicated by the Rx +1.75 -2.75 x 090 is: ✔Correct Answer-mixed
astigmatism
optical cross: +1.75 on 90 meridian, +1.75 -2.75 = 1.00 on 180 meridian
60-1.75 = 58.25
60+1.00 = 61
one is under 60 and one is over 60
Tempering a lens by heat treating results in a lens being: ✔Correct Answer-more resistant to
impact
A slab off lens is for the correction of ✔Correct Answer-excessive prism imbalance at the
reading level
Chem tempering makes a glass lens more impact resistant by placing the lens in a potassium
nitrate bath. The lens undergoes a process known as: ✔Correct Answer-Ion Exchange
Which wavelengths of light have been indicated as possible contributors to the onset of
cataracts? ✔Correct Answer-350-400
,UV wavelength
When the lenses are laid out and marked for cutting and edging, the lenses are usually
decentered so as to correspond to the patient's pupillary distance after lenses are inserted. This
is done for what reason? ✔Correct Answer-To avoid unwanted prism
If the identical bifocal prescription were made up in glass, (all parameters alike), which lens style
would be the heaviest? ✔Correct Answer-Executive
Light falling on the front surface of a spectacle lens is ✔Correct Answer-partially reflected,
partially absorbed, and the remainder refracted
a concave mirror can focus what kind of light on what kind of image? ✔Correct Answer-
Parallel incident rays forming a real image
White light is broken into its component colors when it is: ✔Correct Answer-Diffracted OR
Refracted
To the viewer, the image seen in a plane mirror appears to be: ✔Correct Answer-As far behind
the mirror as the object is in front of it
Rank the velocity of light in the following mediums: Air, Polycarbonate, Water, Flint Glass
✔Correct Answer-Flint Glass (181), Polycarbonate (194), Water (225), Air (300)
A lens dispersing white light into is component colors is an example of ✔Correct Answer-
Chromatic Aberration
The optical center of a lens is ✔Correct Answer-a lens location of zero deviation of the optical
axis
Light rays passing through a prism are deviated in what direction? ✔Correct Answer-toward
the base
Light travels outward in all directions from its source. The best explanation of this is that light
takes the form of: ✔Correct Answer-Wave fronts
The distance between the crest of one wave and the crest of the next one is called: ✔Correct
Answer-Wavelength
The interpretation of the range of wavelengths of visible light varies but is generally accepted as
lying between: ✔Correct Answer-400-700 nm
The breaking up of white light into its component colors by a lens or prism is called ✔Correct
Answer-dispersion
, The color in white light that is refracted the most after passing through a refracting test medium
is ✔Correct Answer-Violet
The reflection of light from a surface is most influenced by ✔Correct Answer-The regularity of
the surface, meaning the smoothness and texture
Light rays originating at a distant point source are described as being ✔Correct Answer-
Parallel
Which rays all lie in the same plane? ✔Correct Answer-Incident, reflected, normal
The bending of a ray of light when it goes from one medium to another is called ✔Correct
Answer-Refraction
A ray of light, passing from a dense to a less dense medium is bent ✔Correct Answer-away
from the normal
The concept or use of the term "normal" is that it is an imaginary line that is ✔Correct
Answer-perpendicular to the medium's surface at the point of incidence of the ray
A correct statement regarding the law of refraction (Snell's law) is that ✔Correct Answer-light
bends toward the normal when it enters a medium denser than the one in which it was
traveling
Any bundle of rays passing through a converging lens is made ✔Correct Answer-more
converging
The ray that can pass through a lens without being refracted is called ✔Correct Answer-The
axial ray
The angle of incidence, for which the angle of refraction is 90 degrees is called the ✔Correct
Answer-critical angle
When parallel incoming rays strike a convex mirror, the reflected rays ✔Correct Answer-seem
to originate from behind the mirror
A ray entering a less dense medium, striking the interface at an angle greater than the critical
angle will be ✔Correct Answer-Totally reflected internally
The image formed at the secondary focal point of a converging lens is ✔Correct Answer-a
virtual image
the image formed in the eye is ✔Correct Answer-real, inverted, and smaller
