|
| 1. As the frame size increases the thickness will: |
|
A.
|
Remain the same |
|
B.
|
Decrease |
|
C.
|
Increase |
|
D.
|
None of the above |
|
|
| 2. The Effective Diameter is equal to: |
|
A.
|
The A box measurement plus the DBL |
|
B.
|
The diagonal of the shape |
|
C.
|
2 times the longest radius of that shape |
|
D.
|
The diagonal of the shape minus the DBL |
|
|
| 3. To find the best E.D. value: |
|
A.
|
Consult "Frame Facts" |
|
B.
|
Call the lab |
|
C.
|
Read it off of the temple |
|
D.
|
Measure the diagonal |
|
|
| 4. Which of the following elements does not effect finished thickness? |
|
A.
|
Decentration |
|
B.
|
Index of Refraction |
|
C.
|
Frame Size |
|
D.
|
Lens Color |
|
|
| 5. Decentration on a minus lens will: |
|
A.
|
Increase center thickness |
|
B.
|
Decrease edge thickness |
|
C.
|
Increase edge thickness |
|
D.
|
Decrease center thickness |
|
|
| 6. Increasing frame size on a plus lens will : |
|
A.
|
Increase center thickness |
|
B.
|
Decrease edge thickness |
|
C.
|
Increase edge thickness |
|
D.
|
Decrease center thickness |
|
|
| 7. All things being equal, lens thickness will decrease as: |
|
A.
|
Frame size increases |
|
B.
|
Index of refraction increases |
|
C.
|
Decentration increases |
|
D.
|
Center thickness increase |
|
|
| 8. Reducing the center thickness of a minus lens by .5 mm will: |
|
A.
|
Have no effect on edge thickness |
|
B.
|
Reduce the edge by more than .5 mm |
|
C.
|
Reduce the edge by the same .5 mm |
|
D.
|
None of the above |
|
|
| 9. Sagittal Value refers to the thickness of a minus lens with: |
|
A.
|
Power above 6 diopters |
|
B.
|
A zero center thickness |
|
C.
|
A zero edge thickness |
|
D.
|
A 1.5 mm center |
|
|
| 10. The smallest diameter blank from which a job will cut from is determined by: |
|
A.
|
Calling the lab |
|
B.
|
Doubling the decentration and adding it to the E.D. |
|
C.
|
Subtracting the eye size from the frame pd. |
|
D.
|
Multiplying the DBL times the Index of refraction minus one |
|
|
| 11. The Sag Lens Formula: |
|
A.
|
Does not apply to lenses with spherical curves. |
|
B.
|
Only applies to lenses with spherical curves |
|
C.
|
Only applies to lenses with aspheric curves |
|
D.
|
All of the above. |
|
|
| 12. In a cylinder lens if the strongest meridian does not run exactly through the E.D. meridian the lens thickness computation will: |
|
A.
|
Predict lens thickness to be slightly thicker than actual |
|
B.
|
Be of no value what so ever |
|
C.
|
Predict lens to be slightly thinner than actual |
|
D.
|
Predict the thickness exactly. |
|
|
| 13. If the computed thickness is greater than the patient would accept the dispenser should: |
|
A.
|
Apologize for wasting the patient's time |
|
B.
|
Refer them back to the doctor |
|
C.
|
Rework the variables to achieve a different outcome |
|
D.
|
Select a larger frame |
|
|
| 14. The sagittal value of a lens assumes a zero center or edge thickness and records the distance from |
|
A.
|
The front tangent of the lens to the back tangent of the lens |
|
B.
|
The pupil to the front of the lens |
|
C.
|
The pupil to the back of the lens |
|
D.
|
The top of the b box to the midpoint of the a box. |
|
|
| 15. In the sag formula, the value “n” refers to the |
|
A.
|
Abbe value |
|
B.
|
Specific gravity |
|
C.
|
Index of refraction |
|
D.
|
Lens power |
|
|
| 16. In the sag formula, the value of the “radius” is derived from a circle that is derived from computing : |
|
A.
|
2 times the decentration plus the effective diameter |
|
B.
|
the index of refraction plus the center thickness |
|
C.
|
decentration plus the center thickness minus a constant of 2000 |
|
D.
|
abbe value plus the specific gravity of the material |
|
|
| 17. Which of the following wearers will receive the greatest cosmetic benefit from aspheric lenses? |
|
A.
|
Astigmatic wearers |
|
B.
|
High minus wearers |
|
C.
|
High plus wearers |
|
D.
|
IOL wearers |
|
|
| 18. The index of refraction of polycarbonate is |
|
A.
|
1.59 |
|
B.
|
1.53 |
|
C.
|
1.50 |
|
D.
|
1.39 |
|
|
| 19. The index of refraction of CR-39 plastic is |
|
A.
|
1.59 |
|
B.
|
1.53 |
|
C.
|
1.50 |
|
D.
|
1.39 |
|
|
| 20. The Sag value and final center thickness of a CR lens for the following values is Rx +4.00D sph, A 50, B 32, DBL 17, ED 52, PD 61, Edge thickness 2.2mm |
|
A.
|
3.4mm, 4.9mm |
|
B.
|
3.4mm, 5.6mm |
|
C.
|
3.0mm, 5.0mm |
|
D.
|
2.9mm, 5.6mm |
|