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| 1. All of the following are part of the electromagnetic spectrum except |
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A.
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Gamma radiation |
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B.
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White light |
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C.
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Ultraviolet radiation |
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D.
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Radon |
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| 2. Colors with shorter wavelengths have ________ frequencies, longer wavelengths __________. |
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A.
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Lower, higher |
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B.
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Higher, lower |
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C.
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Equivalent, shorter |
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D.
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Higher, even higher |
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| 3. Light travels at ___________velocity. |
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A.
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200,000 km/sec |
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B.
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300,000 km/sec |
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C.
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100,000 miles/sec |
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D.
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1.500000 miles/sec |
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| 4. The ____________ the refractive index, the ___________ the velocity of light through the medium. |
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A.
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Higher, slower |
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B.
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Slower, higher |
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C.
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Shorter, longer |
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D.
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More uniform, faster |
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| 5. _____________ wavelengths with __________ frequencies move ____________ slower through a transparent medium. |
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A.
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Shorter, lower, slower |
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B.
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Longer, higher, slower |
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C.
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Shorter, higher, slower |
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D.
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Longer, lower, faster |
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| 6. The chroma that a patient might notice as color or blur in the lens periphery is caused by |
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A.
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Axial chromatic aberration |
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B.
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Axial radial motion |
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C.
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Lateral chromatic aberration |
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D.
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Lateral peripheral technology |
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| 7. A wavelength of about __________nm is used in the US to specify the refractive index of a specific material. |
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A.
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522 |
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B.
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546 |
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C.
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587 |
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D.
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656 |
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| 8. __________ Abbe values ___________ a lens' chromatic aberration. |
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A.
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Higher, increases |
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B.
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Higher, decreases |
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C.
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Lower, increases |
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D.
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Lower, does not affect |
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| 9. Generally, the higher the refractive index, the ___________ the Abbe value. |
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A.
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Higher |
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B.
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The same |
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C.
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The lower |
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D.
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Are not related |
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| 10. Place the following materials into ascending order of Abbe values. |
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A.
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Hard resin, Trivex, 1.6 (MR8), 1.66, polycarbonate, crown glass |
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B.
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Trivex, hard resin, 1.6 (MR8), 1.66, crown glass, polycarbonate |
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C.
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Polycarbonate, crown glass, 1.6 (MR8), Trivex, 1.66, hard resin |
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D.
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Polycarbonate, 1.66, 1.6 (MR8), Trivex, crown glass, hard resin |
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| 11. Axial chromatic aberration, in a plano lens, when viewing a red sign |
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A.
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Causes the appearance of a brighter red |
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B.
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Has no effect |
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C.
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Creates about .2D of ACA |
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D.
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Makes a rainbow of color at lens center |
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| 12. Color fringing around objects is the result of |
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A.
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Lateral chromatic aberration |
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B.
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Axial chromatic aberration |
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C.
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More deviation of blue light than red |
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D.
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A&C |
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| 13. The red/green duochrome test in a refraction is possible because |
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A.
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The eye has about 1D of axial chromatic aberration |
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B.
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The eye has about 1D of lateral chromatic aberration |
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C.
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The eye has about 0.1D of axial chromatic aberration |
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D.
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The eye has about 0.1D of lateral chromatic aberration |
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| 14. All of the following were issues with early polycarbonate lenses except, which were blamed on chromatic aberration |
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A.
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Yellow and hazy lenses |
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B.
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Poor processing techniques |
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C.
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Asphericity |
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D.
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Wrong base curves chosen |
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| 15. When comparing the Lateral chroma of a -4D polycarbonate and 1.66 high index lens, (15mm from center), the 1.66 lens |
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A.
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Produces a much clearer lens |
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B.
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Has an acuity that is about the same |
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C.
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Improves visual acuity significantly |
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D.
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A & C |
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| 16. Most wearers |
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A.
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Have problems with low Abbe lens materials |
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B.
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Adapt or are not bothered by the effects of Abbe |
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C.
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Prefer higher Abbe materials in low powered lenses |
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D.
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Have problems with high Abbe lens materials |
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| 17. All are ways to minimize the effects of chroma except |
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A.
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Always use low Abbe lens materials |
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B.
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Minimize lens decentration |
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C.
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Use recommended base curves |
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D.
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If chroma is suspect, consider higher Abbe materials |
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| 18. All of the following are the benefits of better peripheral lens designs (in low Abbe lenses) except |
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A.
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Reduces off axis errors |
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B.
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Reduces the additive effects of oblique errors and chroma |
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C.
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Increases off axis errors |
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D.
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Closer fitting lenses |
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| 19. All of the following are correct statements except |
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A.
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Low Abbe by itself is not a reason to reject a lens material. |
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B.
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A rejection of polycarbonate lenses may be due to other factors besides chroma. |
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C.
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Color fringing due to chroma has no effect on vision. |
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D.
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Well-centered lenses in a frame minimize chroma. |
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| 20. The main reason to not suggest SV lens fitting heights, especially in higher index lenses is |
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A.
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A smaller diameter blank size will be required. |
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B.
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Lens thinness at the top and bottom of the frame will be different |
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C.
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A larger diameter blank size will be required. |
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D.
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B & C |
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