Test two
1. The following about Fresnel's prism are true:
a. its power is determined the thickness of the base 

b. the visual acuity is affected by the power of the prism 

c. it is normal fitted to the front of the spectacle 

d. the maximum prismatic power than an adult can tolerate is usually 
    around 15 dioptres 

e. dividing the strength of the prism between the two eyes improves the 
    comfort of the patient

2. Regarding the fusional reserves:

a. the horizontal fusional reserve is higher than the vertical fusional reserve 

b. the positive fusional reserve is higher for distance than near 

c. the positive fusional reserve is affected by the subject's 
    accommodative reserve 

d. the horizontal fusional reserve decreases with age 

e. the vertical fusional reserve is decreased in patient with reduced 
   accommodative reserve


3. In the normal eye, resolution:

a. depends on cone separation 

b. is 6/6 or better 

c. depends on the size of the pupil 

d. is about 10 minutes of arc 

e. can be tested with the Sheridan-Gardner test


4. The vernier acuity (hyperacuity):

a. is the ability of  the eye to detects  two images placed close together 

b. depends on the separation of cone 

c. in normal eye is less than 8 seconds of arc 

d. requires the presence of binocular single vision 

e. is used when performing applanation tonometer


5. True statements about diffraction include:

a. diffraction is increased when light passes through a smaller than a 
    bigger aperture 

b. diffraction is increased with shorter than longer light wavelength 

c. diffraction which occurs when the light passes through the pupil is 
    referred to as Fraunhofer diffraction 

d. produces an Airy's disc which affects the resolving power of the eye 

e. produces an Airy's disc which is bigger in a smaller than a bigger pupil

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