Quiz 4 Flashcards
Most ophthalmic lenses have no aberrations.
a. True
b. False
b. False
In curvature of field, the image is curved convex toward the object.
a. True
b. False
b. False
As light strikes a lens with a spherical front surface, it refracts more at the periphery than near the center.
a. True
b. False
a. True
Chromatic aberration is a result of the nature of the material from which the lens is made.
a. True
b. False
a. True
In coma, the aberration is a result of rays of light parallel to the lens surface.
a. True
b. False
b. False
When light strikes an object, 3 things occur. They include:
Refraction
Absorption
Reflection
a. True
b. False
a. True
As a ray of light passes from a less dense to a more dense material at an oblique angle, the refracted ray will be deviated ______ the normal.
a. Toward
b. Away
c. Parallel to
a. Toward
As a ray of light passes from a more dense to a less dense material at an oblique angle, the refracted ray will be deviated _____ the normal.
a. Toward
b. Away
c. Parallel to
b. Away
A concave surface has ______ dioptric power.
a. Plus
b. Minus
c. Plano
b. Minus
A convex surface has ______ dioptric power.
a. Plus
b. Minus
c. Plano
a. Plus
A plano surface has ______ dioptric power.
a. Plus
b. Minus
c. Plano
c. Zero
A high plus lens will show _______ distortion.
a. Pin cushion
b. Barrel
c. Radio Wave
a. Pin cushion
A high minus lens will show _______ distortion.
a. Pin cushion
b. Barrel
c. Radio wave
b. Barrel
A surface with a shorter radius will have a flatter curve
a. True
b. False
b. False
A surface with a flatter curve will have less dioptric power.
a. True
b. False
a. True
All lenses moved farther from the eye will gain in plus power. We compensate for this by adding minus power.
a. True
b. False
a. True
Vertex Distance compensation should be considered when the total power of the lens, in any meridian, is +/- 7.00 or greater
a. True
b. False
a. True
In the surface power formula, we must be sure that “r” (radius) is in Meters, not millimeters or centimeters.
a. True
b. False
a. True
The Law of Reflection states that, “The angle of incidence is always greater than the angle of reflection”
a. True
b. False
b. False
Solve the following Vertex Compensation example using charts:
OD -13.00 -2.00 x090
OS -15.00 -1.00 x090
Moved 5mm closer to the eye
What is the Compensated Power: (What to Order)
a. OD -12.00 -2.00 x090
OS -13.00 -1.00 x090
b. OD -14.00 -2.00 x090
OS -16.00 -1.00 x090
c. OD -12.25 -1.75 x090
OS -14.00 -0.87 x090
d. OD -13.00 -2.00 x090
OS -15.00 -1.00 x090
c. OD -12.25 -1.75 x090
OS -14.00 -0.87 x090
