Test 9
1. The following are true about astigmatism:
a. total ocular astigmatism is equivalent to corneal astigmatism plus lenticular 
b. when a patient with corneal astigmatism is fitted with a soft contact lens, most of the 
    astigmatism is transferred to the anterior surface of the contact lens
c. hard spherical contact lens is better than soft spherical contact lens in correcting 
    corneal astigmatism
d. lenticular astigmatism cannot be corrected with contact lens
e. lenticular astigmatism can be corrected with cataract surgery

2. The following are true in a patient with the following findings:
Spectacle prescription:  -3.00D

Keratometry reading:    7.80mm (43.25D) along 1800
                                         7.50mm (45.00D) along 900

a. the spectacle prescription is wrong
b. there is a 1.75D with the rule corneal astigmatism
c. there is no lenticular astigmatism 
d. a spherical hard contact lens is useful in correcting this patient's vision
e. a spherical soft contact lens can fully correct this patient's vision


3. The following are true about astigmatism:

a. oblique astigmatism occurs when the principal meridian is not at 900 to each other
b. a right corneal suture superiorly causes a with-the-rule astigmatism
c. compound myopic astigmatism occurs when both meridian focus light in front of the 
d. simple myopic astigmatism occurs when one meridian is emmetropic and the other is 
e. mixed astigmatism occurs when one meridian is myopic and the other hypermetropic

4. With regard to accommodation:
a. the near point for a myope is closer without wearing correcting glasses
b. measurement of the near point of accommodation with a RAF rule is more accurately 
    performed monocularly than binocularly
c. 'method of spheres' is a useful technique for measuring the amplitude of 
    accommodation in young hypermetropes.
d. accommodation is induced with concave lenses
e. an uncorrected myope (-2D) with a near point of 0.1m has an amplitude of 
    accommodation of 8D.


5. The following are true about colour blindness:
a. protanopia is caused by abnormal red cones
b. tritan is caused by abnormal blue cones
c. deutan is caused by abnormal green cones
d. deuteranomalous trichromatism is the most common type of colour blindness
e. blue cone monochromatism occurs in patients who lose the function of blue cones

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