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The speed of light is:
a. 160,000 meters / second
b. 186,000 meters / second
c. 169,000 miles / hour
d. 186,000 miles / second
186,000 miles / second
In a minus powered lens light rays ____ and come to a focal point ____ the lens.
a. Converge, behind
b. Converge, in front of
c. Diverge, in front of
d. Diverge, behind
Diverge, in front of
Light rays pass through a lens and converge at a point 50cm behind the lens, what is the power?
a. 0.20 D
b. 0.02 D
c. 2.00 D
d. 0.50 D
1 Prism Diopter can be described as deviating a ray of light:
a. 1 meter / 1 centimeter
b. 10 centimeters / 1000 centimeters
c. 1 millimeter / 1 meter
d. 1 meter / 1 millimeter
10 centimeters / 1000 centimeters
3 Prism Diopters base in on the right eye can also be described as:
a. 3 @ 000º
b. 3 @ 180º
c. 3 @ 270º
d. 3 @ 090º
3 @ 000º
Using Prentice's Rule a -4.00 lens must be decentered ___ to induce 1.00 Prism Diopter:
a. 1.0 mm
b. 2.5 mm
c. 10 mm
d. 2.0 cm
When the direction of light changes as it passes from one medium to another, it is called
A +3.00D lens has the following prismatic effect 8 mm below the optical center:
a. 2.4 base up
b. 2.4 base down
c. 2.4 base out
d. 2.4 base in
2.4 base up
One prism diopter _______ .
a. Focuses parallel light rays at 40 cm
b. Deviates a ray of light 1 cm at a distance of one meter
c. Deviates a ray of light towards the apex
d. Focuses parallel rays of light at one meter
Deviates a ray of light 1 cm at a distance of one meter
One of the ways of identifying a lens with minus power is to look for:
a. Parallel rays of light coming to a point focus behind lens
b. Lens thicker in the center than the edge
c. Objects seen through the lens are brighter
d. Objects seen through the lens seem to move in the same direction as the lens is moving
Objects seen through the lens seem to move in the same direction as the lens is moving
The focal length of a lens may be altered by:
a. Making the lens smaller
b. Making the lens larger
c. Changing the curvature of one surface
d. Coating the surface to prevent reflections
Changing the curvature of one surface
A +5.00 diopter lens decentered 2 mm creates ____ diopters of prism.
The P.D. written on the order is mistakenly noted as 70 mm, when the actual measurement should be 66 mm. What unwanted prism would be found in the prescription if the distance prescription is O.U. -15.00D sphere?
a. 3ΔD base in each eye
b. 3ΔD base out each eye
c. 2ΔD base in each eye
d. 2ΔD base out each eye
3ΔD base in each eye
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