ABO Advance Exam
Comprehensive Questions with
Verified Answers Graded A+
The amount of reflection of each surface of CR-39 lenses is approximately - Answer: 4%
The absorption of light in lenses is classified by two variables. What are they?
A. base curve and thickness
B. index of refraction and thickness
C. thickness and lens transmission
D. tint and lens transmission - Answer: D. tint and lens transmission
The denser the tint in a lens
A. the greater the transmission of light through the lens
B. the greater internal reflections in the lens
C. the less transmission of light through the lens
D. the fewer internal reflections in the lens - Answer: C. the less transmission of light through
the lens
Standard transmissions in sunlenses should range between - Answer: 15% and 30%
,If a person has exposure to sunlight at least 2 hours or more during the day, - Answer: their
ability to adapt to night vision is compromised if they don't protect their eyes from the sun
exposure
A characteristic of dark tinted glass lens with an Rx of +4.00D sphere would be - Answer: dark in
the center and lighter on the edge
Given a high plus or high minus Rx, which lens material would offer the best choice for uniform
density in a sunlens?
A. Pigmented glass
B. CR-39
C. Trivex
D. B & C - Answer: D. B & C
Although this may be the most popular color for sunlenses, it is not recommended for patients
with emerging cataracts - Answer: Gray
_ added to any color increases contrast - Answer: Yellow
_ is better than _ for improving contrast.
A. Violet/Gray
B. Green/Gray
C. Gray/Green
D. Gray/Violet - Answer: B. Green/Gray
Glare is of more concern to which wearer?
,A. Red haired patient
B. Computer user
C. Cataract patient
D. Presbyope - Answer: C. Cataract patient
_ are generally inorganic materials (metals or minerals) that are vacuum deposited to add color
on glass lenses to give a uniform density of color on the lenses - Answer: Vacuum color coatings
What company introduced CR-39 lenses? - Answer: PPG Industries
What is the index of refraction of polycarbonate? - Answer: 1.586 or 1.59
The quality of today's polycarbonate lenses has been improved due to the demand of what
product? - Answer: Compact discs
Birefringence is also referred to as _ and can result in distortion reducing the visual performance
to the wearer? - Answer: Double refraction
What is the index of refraction of Trivex? - Answer: 1.53
Features and benefits of Trivex include _
A. Superior optics
B. Impact resistance
C. Ultra-light weight
D. All of the above - Answer: D. All of the above
, Visible glare can be dangerous, because it can not only wash out colors, but in some instances
can cause - Answer: photokeratitis
Polarized filters are made by stretching thin sheets of _ in one meridian - Answer: polyvinyl
alcohol
Two methods for orienting the polarized filters into lenses include - Answer: laminating and
molded
As light reaches a polarizing filter, - Answer: light in only one plane will pass through, having the
other absorbed by the filter, thereby reducing glare
Polarized lenses were may not be recommended for which visual task? - Answer: Any visual task
that may include using LCD instrumentation
Photochromic lenses were introduced by - Answer: corning in 1964
The color change in photochromic lenses occurs as a result of _ that are added to the molten
glass - Answer: silver halide crystals
The first successful plastic photochromic lenses were introduced by - Answer: transitions in
1991
Imbibed technology means - Answer: that the photochromic technology is on the surface of the
lenses, which makes the color density not uniform throughout the lens
Comprehensive Questions with
Verified Answers Graded A+
The amount of reflection of each surface of CR-39 lenses is approximately - Answer: 4%
The absorption of light in lenses is classified by two variables. What are they?
A. base curve and thickness
B. index of refraction and thickness
C. thickness and lens transmission
D. tint and lens transmission - Answer: D. tint and lens transmission
The denser the tint in a lens
A. the greater the transmission of light through the lens
B. the greater internal reflections in the lens
C. the less transmission of light through the lens
D. the fewer internal reflections in the lens - Answer: C. the less transmission of light through
the lens
Standard transmissions in sunlenses should range between - Answer: 15% and 30%
,If a person has exposure to sunlight at least 2 hours or more during the day, - Answer: their
ability to adapt to night vision is compromised if they don't protect their eyes from the sun
exposure
A characteristic of dark tinted glass lens with an Rx of +4.00D sphere would be - Answer: dark in
the center and lighter on the edge
Given a high plus or high minus Rx, which lens material would offer the best choice for uniform
density in a sunlens?
A. Pigmented glass
B. CR-39
C. Trivex
D. B & C - Answer: D. B & C
Although this may be the most popular color for sunlenses, it is not recommended for patients
with emerging cataracts - Answer: Gray
_ added to any color increases contrast - Answer: Yellow
_ is better than _ for improving contrast.
A. Violet/Gray
B. Green/Gray
C. Gray/Green
D. Gray/Violet - Answer: B. Green/Gray
Glare is of more concern to which wearer?
,A. Red haired patient
B. Computer user
C. Cataract patient
D. Presbyope - Answer: C. Cataract patient
_ are generally inorganic materials (metals or minerals) that are vacuum deposited to add color
on glass lenses to give a uniform density of color on the lenses - Answer: Vacuum color coatings
What company introduced CR-39 lenses? - Answer: PPG Industries
What is the index of refraction of polycarbonate? - Answer: 1.586 or 1.59
The quality of today's polycarbonate lenses has been improved due to the demand of what
product? - Answer: Compact discs
Birefringence is also referred to as _ and can result in distortion reducing the visual performance
to the wearer? - Answer: Double refraction
What is the index of refraction of Trivex? - Answer: 1.53
Features and benefits of Trivex include _
A. Superior optics
B. Impact resistance
C. Ultra-light weight
D. All of the above - Answer: D. All of the above
, Visible glare can be dangerous, because it can not only wash out colors, but in some instances
can cause - Answer: photokeratitis
Polarized filters are made by stretching thin sheets of _ in one meridian - Answer: polyvinyl
alcohol
Two methods for orienting the polarized filters into lenses include - Answer: laminating and
molded
As light reaches a polarizing filter, - Answer: light in only one plane will pass through, having the
other absorbed by the filter, thereby reducing glare
Polarized lenses were may not be recommended for which visual task? - Answer: Any visual task
that may include using LCD instrumentation
Photochromic lenses were introduced by - Answer: corning in 1964
The color change in photochromic lenses occurs as a result of _ that are added to the molten
glass - Answer: silver halide crystals
The first successful plastic photochromic lenses were introduced by - Answer: transitions in
1991
Imbibed technology means - Answer: that the photochromic technology is on the surface of the
lenses, which makes the color density not uniform throughout the lens
