The percentage of reflection for each surface of CR-39 plastic lenses is about: -
ANSWER 4%
There are two variables involved in the classification of light absorption in
lenses. What are they? - ANSWER Tint and lens transmission
The more dense the tint in a lens, the _____: - ANSWER Less transmission of
light through the lens
Standard transmission in sun lenses should range between: - ANSWER 15%
and 30%
If one has exposure to sunlight at least 2 hours or more during the day, his
_____ - ANSWER Ability to adapt to night vision is compromised if he does
not protect his eyes from sun exposure.
A characteristic of a dark tinted glass lens with an RX of +4.00D sphere would
b _____ - ANSWER Dark in the center and lighter on the edge
Given a high plus or minus RX, which lens material would offer the best choice
for uniform density in a sunlens? - ANSWER cr-39 plastic and trivex
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: - ANSWER green
Glare is of more concern to which wearer? - ANSWER 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
Which company introduced CR-39 plastic lenses? - ANSWER PPG Industries
What is the index of refraction of polycarbonate? - ANSWER 1.59
Because of the demand of what product has the quality of today's polycarbonate
lenses been improved? - ANSWER compact discs
Birefringence is also known 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_____: - ANSWER superior optics,
impact resistance, ultra-light weight (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
ANSWER 4%
There are two variables involved in the classification of light absorption in
lenses. What are they? - ANSWER Tint and lens transmission
The more dense the tint in a lens, the _____: - ANSWER Less transmission of
light through the lens
Standard transmission in sun lenses should range between: - ANSWER 15%
and 30%
If one has exposure to sunlight at least 2 hours or more during the day, his
_____ - ANSWER Ability to adapt to night vision is compromised if he does
not protect his eyes from sun exposure.
A characteristic of a dark tinted glass lens with an RX of +4.00D sphere would
b _____ - ANSWER Dark in the center and lighter on the edge
Given a high plus or minus RX, which lens material would offer the best choice
for uniform density in a sunlens? - ANSWER cr-39 plastic and trivex
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: - ANSWER green
Glare is of more concern to which wearer? - ANSWER 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
Which company introduced CR-39 plastic lenses? - ANSWER PPG Industries
What is the index of refraction of polycarbonate? - ANSWER 1.59
Because of the demand of what product has the quality of today's polycarbonate
lenses been improved? - ANSWER compact discs
Birefringence is also known 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_____: - ANSWER superior optics,
impact resistance, ultra-light weight (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
