Assessment of the quality of the peripheral curves (blends of a rigid contact lens) is achieved
by
the use of thea. profile analyzer
b. shadow graph
c. keratometer
d. burton light -Answer a. profile analyzer
Contact lens power should be specified ina. back vertex power
b. sphero-cylinder power
c. power in situ
d. posterier apical radius -Answer a. back vertex power
The slit-lamp illumination that gives an overall view of the cornea but limits detail isa.
sclerotic scatter
b. diffuse
c. specular reflection
d. oscilatory -Answer b. diffuse
When a keratometric miers reflected off a soft contact lens are only clear when the wearer
blinks, the lens fit is tooa. small
,b. large
c. steep
d. flat -Answer c. steep
Transient keratometric mier distortion is usually due to-
a. pre-ocular tear film abnormalities
b. prolonged rigid lens wear
c. prolonged soft lens wear
d. irregular corneal astigmatism -Answer a. pre-ocular tear film abnormalities
Epithelial edema which manifests itself clinically as central corneal haze, is verified by the slit
lamp using sclerotic scatter illumination. What specific technique does the examiner use to
see
this condition?
a. the naked eye and an angle between the slit lamp beam and the eye of 90˚
b. the blue cobalt filter of the slit lamp and an angle of about 45˚
c. the green filter of the slit lamp with high magnification
d. high magnification and an angle between the beam and scope of 180˚-Answer a. the
naked eye and an angle between the slit lamp beam and the eye of 90˚
,With a rigid contact lens in place a flourescein pattern shows a narrow bend horizontally wih
a
concentration of flourescein inferiorly and superiorly under the lens. Which one of the
following
type of astigmatism is represented by this pattern?
a. lenticular astigmatism
b. residual astigmatism
c. against the rule astigmatism
d. with the rule astigmatism -Answer d. with the rule astigmatism
Refractive Rx -3.00 -1.00 x 170
K's 42.00 @ 170/43.00 @ 80
Given the above Rx and K's he following diagnostic toric soft lens was used:
B.C. 8.8
Power -3.00 -1.00 x 180
During dianostic evalutation, the above lens rotated 10 clockwise. The lens ordered should
have
an axis of:
a. 10
, b. 180
c. 170
d. 160 -Answer b. 180
Given the same circumstances from the above question, once the correctly ordered lens has
been dispensed, the rotational marks should settle at _______.
a. 6 o clock
b. 10 clockwise rotation
c. 10 counter clockwise rotation
d. none of the above -Answer b. 10 clockwise rotation
An instrument that allows simultaneous verification of lens diameter, optic zone width, and
peripheral curve width is:
a. measuring magnifier
b. ophthalmometer
c. profile analyzer
d. radiuscope -Answer a. measuring magnifier
(the book says d. radiuscope)
The instrument used for magnification of the edge of a rigid CL is a _______.