Test one
1. True statements about the circle of least confusion include:
a. it is the clearest image that a spherocylindrical lens can 

b. it is located at a point corresponding to the spheroequivalent 
    of a spherocylindrical lens 

c. it is in the mid point of the Sturm's interval 

d. it is increased if the distance between the two focal lines 
    of a spherocylindrical lens is increased 

e. the shape of the circle of least confusion is influenced by the 
    shape of the spherocylindrical lens

2. The following are true:
a. simple myope can be corrected fully with 
    minus sphere only 

b. simple myopic astigmatism can be corrected fully 
    with a minus sphere lens and a minus cylindrical lens 

c. compound myopic astigmatism can be corrected 
    fully with a plus sphere lens and a minus cylinder 

d. simple hyperopic astigmatism occurs when one 
    principal meridian is on the retina and the other is 
    behind the retina 

e. mixed astigmatism occurs when one principal meridian 
    is on the retina and the other is behind the retina


3. True statements about ultrasound include:

a. the ultrasound used in diagnosis has a frequency of greater 
    than 20 kHz 

b. piezoelectric effect is used to emit ultrasound as well 
    as analysing the echo 

c. ultrasound is propagated as a transverse wave through 
    a medium 

d. ultrasound travels faster through vitreous than the lens 

e. ultrasound with longer wavelength penetrates the tissue 
    deeper than one with shorter wavelength


4. The following are true about Hess's test:

a. ocular dissociation is necessary 

b. it can be used to calculate the amount of ocular deviation 

c. a visual acuity of better than 6/12 is essential 
    for the testing 

d. the eye with restricted movement usually has a smaller 
    field on the the Hess's chart 

e. it can be used to test the field of binocular single vision.


5. True statements about dissociated vertical deviation include:

a. it is unilateral in 90% of the cases 

b. it is associated with infantile esotropia 

c. it is caused by inferior oblique overaction 

d. it can be diagnosed with Bielschowsky darkening 
    wedge test 

e. it can be demonstrated with Bagolini filter bar

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