COMPREHENSIVE QUESTIONS AND
SOLUTIONS GRADED A+
◉ An rx with the OD minus and the OS plus is an obvious case of:
a. emmetropia
b. antimetropia
c. hetermetropia
d. isometropia. Answer: b. antimetropia
◉ 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. Answer: c. changing the
curvature of one surface
◉ When light entering the eye, without corrective lenses, comes to a
focus partially in front of the retina and partially in back of the
retina, the patient's refractive error is:
,a. myopia
b. hyperopia
c. mixed astigmatism
d. antimetropia. Answer: c. mixed astigmatism
◉ When light entering the eye, without corrective lenses, comes to a
focus in front of the retina, the patient's refractive error is:
a. myopia
b. presbyopia
c. hyperopia
d. antimetropia. Answer: a. myopia
◉ The relationship of front and back curvatures on a spectacle lens
will determine:
a. refractive power
b. segment position
c. effective diameter
d. decentration. Answer: a. refractive power
,◉ Spherical aberration results from the fact that:
a. a spherical lens bends rays less near the OC than at the edge
b. a spherical lens has chromatic aberration
c. parallel incident rays make equal angles with the surface
d. a spherical lens is actually prismatic in effect and breaks up white
light into separate colors. Answer: a. a spherical lens bends rays near
the OC than at the edge
◉ A source of ultraviolet light is:
a. the sun
b. fluorescent lamps
c. tungsten lamps
d. all of the above. Answer: d. all of the above
◉ The most commonly used prescription for correcting esotropia
caused by muscle imbalance would be:
a. plus sphere
b. minus cylinder
c. base in prism
, d. base out prism. Answer: d. base out prism
◉ The progressive addition lens has a progressive zone or corridor
where power:
a. gradually increases
b. gradually decreases
c. stays the same
d. abruptly changes. Answer: a. gradually increases
◉ The thickness of the ledge of an executive style bifocal is due to
the:
a. lens center thickness
b. location of the O.C.
c. power of the addition
d. gold coating. Answer: c. power of the addition
◉ The correct term used to express the amount of prism in a lens is:
a. degree
b. prism diopter