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Opthalmic Optics
Optometry 217 Fall 07
19
Other
Graduate
10/05/2007

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Cards

Term
What type of material is CR39?
Definition
thermosetting material
Term
What type of material is polycarbonate?
Definition
thermoplastic
Term
What type of material is Trivex?
Definition
quasi thermosetting/thermoplastic
Term
What type of ultraviolet light is 100% blocked by Trivex?
Definition
UVA and UVB below 394 nm
Term
What size ball is used for ANSI Z80.1, dress eyeware?
Definition
0.56 ounce steel ball dropped from 50"
Term
What size ball is used for basic impact and high impact?
Definition
2.4 ounce and 17.6 ounce balls
Term
What size ball does Trivex withstand when dropped at 50"?
Definition
2.2 pound ball
Term
What is the tensile strength of Trivex? Plastic?
Definition
130-180 lbs, Plastic tensile strength is only 30 lbs.
Term
What type of lenses are made by extrusion compression molding?
Definition
Resolution
Term
What is the advantage of extrusion compression molding versus injection compression molding?
Definition
Extrusion compression molding has no material stress, whereas injection compression molding is 150 tons/square inch.
Term
What does it mean that Resolution lenses are birerefringence free?
Definition
There is no manufacturing induced stress distortion.
Term
How much 398 nm UV light does resolution material absorb?
Definition
98%
Term
Can you tint reolution material?
Definition
yes
Term
Is reolution produced in plus powers?
Definition
No, only minus powers
Term
Is the front of a resolution lens aspheric or atoric? What about the back?
Definition
aspheric, atoric
Term
What type of material is Clear 16 and Thin and Dark? How small can you surface their center thickness and still pass the drop ball test?
Definition
1) New glass lense types
2) 1.5 mm
Term
What type of lens is NXT in referring to how its made?
Definition
Injection molded lens
Term
What two type of lenses are ideal for drill mounts?
Definition
Trivex and NXT
Term
Name one advantage of Polycarbonate over NXT?
Definition
Polycarbonate has a slightly higher index of refraction. NXT has a lower specific gravity, higher Abbe number, and is more chemically resistant.
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