Quiz 2 Flashcards
Applying the concept of corrected curve lens theory, choose the best base curve for the following:
Applying for Ashperic Lenses:
+4.00 aspheric
+8.00
Applying the concept of corrected curve lens theory, choose the best base curve for hte following:
-6.00 -2.00 x90 ASHPERIC Lenses
+0.50
Transpose the following Rx:
+2.50 –0.75 x 175
+1.75 +0.75 x85
Transpose the following Rx:
-3.75 +1.25 x 45
–2.50 –1.25 x 135
Applying the concept of corrected curve lens theory, choose the best base curve for the following:
-1.00
+5.50
Write the prescription (Rx) using the powers on the optical cross
-1.50 +4.00 x 180
+2.50 -4.00 x 90
1 and 2
neither Rx is correct
1 & 2
Place the following prescription on the optical cross
+4.00 at 90 -2.00 at 180
+2.00 at 90 +4.00 at 180
+2.00 at 90 +2.00 at 180
+4.00 at 90 +2.00 at 180
+4.00 at 90 +2.00 at 180
Spectacle lenses are prescribed for 4 reasons: refractive errors, faulty binocular vision, protection and comfort.
True
Crown glass is clear, ophthalmic glass and has an index of refraction of 1.49
False
Transpose the following Rx:
+4.00 –1.37 x 62
+2.62 +1.37 x152
Write the prescription (Rx) using the powers indicated on the optical cross
- 0.12 -0.37 x180
- 0.50 -1.37 x90
+0.50 -0.37 x90
-0.12 +0.37 x180
-0.12 -0.37 x180
Applying the concept of corrected curve lens theory, choose the best base curve for the following:
+6.00-2.00 x 90
+11.00
Applying the concept of corrected curve lens theory, choose the best base curve for the following:
-1.00-6.00 x 90
+4.00
All of the following are characteristics of minus lenses except:
Diverge Light
Virtual Focus
Thinner at center, thicker at the edges
Minify Image
Effective power Increases as the Vertex Distance Increases
Shows with motion
Effective power increases as the Vertex Distance Increases
All of the following are advantages of plastic lenses except:
light weight
tints easily
scratches easily
good optics
scratches easily
Put the following Rx on the optical cross. Choose the correct powers with corresponding meridian from the list below:
Plano at 135 -2.00 x 45
All of the following are characteristics of plus lenses except:
Converge light
Virtual focus
Thicker at the center, thinner at the edges
Shows against motion
Effective Power Increases as the Vertex Distance Increases
Virtual focus
Transpose the following Rx:
Plano –2.00 x 180
–2.00 +2.00 x 90
The PRINCIPAL AXIS is an imaginary line that is perpendicular to the lens surface and where light passes through undeviated.
True
CR-39 Stands for Columbia Resin’s 39th formula, and it what we refer to as plastic.
True
What is the Rx from the following optical cross? Powers felt are: -3.50 at 60 plano at 150
- 3.50 -3.50 x60
- 3.50 +3.50 x60
plano -3.50 x150
1 and 2
2 and 3
2 & 3
Transpose the following Rx:
+10.50 +0.75 x 25
+11.25 –0.75 x 115
Applying the concept of corrected curve lens theory, choose the best base curve for the following:
+1.00 sphere
+7.00
Place the following prescription on the optical cross: -1.50 –1.50 x 180
–3.00 at 90 -1.50 x 180
The OPTICAL CENTER is the point on a lens through which a ray of light bends toward the base.
False
