Test 1  (Properties of light and visual function )
1. With regard to optical radiation:
a. the wavelengths of visible light lies between 400nm 
    and 780nm

b. ultraviolet A has a shorter wavelength than ultraviolet C

c. the shorter the wavelength the higher the energy of an 
    individual quanta (photon)

d. the crystalline lens is better at absorbing shorter than 
    longer wavelengths

e. eclipse burn is caused by infrared radiation


2. The following are true about colour vision:
a. deuteranomaly is more common than deuteranopia

b. blue pigment gene is found on chromosome X

c. red-green defect is common in acquired optic 
    nerve disease

d. blue-yellow defect is common in glaucoma 

e. blue cone is sensitive to shorter wavelength than green 

3. In colour vision testing:
a. the Fransworth-Munsell hue 100 test contains 84 
    colour discs

b. the colours of the Fransworth-Munsell hue 100 test 
    differs in hue and saturation

c. Ishihara test plates are designed mainly for congenital 
    red-green colour defects.

d. Ishihara test plates can not be used by pre-verbal 

e. Lanthony New Colour Test is only suitable for adults


4. With regard to light scattering:

a. it does not occur in vacuum

b. it is proportionally to the the wavelength of the light

c. vitreous is best viewed with light of short wavelength 
    as it scatters more

d. the cornea scatters about 10% of the incoming light

e. it is responsible for poor vision in corneal oedema


5. The following equipment are used in fluorescein angiography:
a.  a fundus camera with optics similar to 
     direct ophthalmoscope

b. a filter that allows exciting light less than 510nm

c. a filter that allows exciting blue light

d. a filter in front of the photographic film or 
    the digital camera that blocks blue light

e. a filter in front of the photographic film or the digital 
    camera that blocks light of less than 510nm


6. The following are true about indocyanine green angiography (ICG):
a. indocyanine green has a larger molecule than sodium 

b. indocyanine green emits light in the infrared range

c. ICG is better at visualizing the choroidal vasculature 
    than sodium fluorescein angiography because it has a 
    higher protein binding and only partially absorbed by 
    the retinal pigment epithelium

d. ICG is best imaged with photographic film

e. ICG should be avoided in patients with seafood allergy


7. Regarding diffraction:

a. it is best explained with the wave theory of light

b. it occurs when there is an obstruction to the light

c. both constructive and destructive interference occurs 

d. it increases with longer wavelength

e. it prevents the formation of a point image from a point 

8. The Airy's disc:

a. is formed by diffraction

b. contains a central bright disc that receives 90% of the 
    luminance flux

c. is surrounded by concentric light and dark rings

d. is proportional to the wavelength of the light

e. is proportional to the diameter of the pupil


9. The following tests are used in testing the vision of pre-verbal 
a. Log MAR


c. Catford drum

d. Cardiff card

e. Sheridan-Gardiner tests


10. Regarding visual acuity:
a. it can be represented a reciprocal of the minimum 
    angle of resolution

b. it varies with the region of the retina

c. it is affected by general illumination

d. it is affected by the colour of the test objects

e. it is affected by the time of exposure

11. Pinhole:

a. if less than 1mm diameter impairs the image quality

b. abolishes the need for the eye to focus

c. increases the depth of focus

d. increases the depth of field

e. improves ametropia of less than 6 D

12. Contrast sensitivity:

a. measures the eye sensitivity to light

b. is inversely proportional to contrast

c. can be measured with Snellen's chart

d. can be measured with VISTECH

e. may be reduced following LASIK 


13. The following are true about birefringence:
a. they have two refractive indices

b. they split a light into two polarized lights

c. polarimetry uses the birefringence of the nerve fibre 
    layer to quantitate its thickness indirectly

d. it is used in pleoptics to produce Haidinger's brushes

e. amyloid when stained with Congo red produces 

14. In stereoscopic vision testing:

a. corresponding retinal areas in both eyes are stimulated

b. the grading is based on the least horizontal disparity of 
    retinal image that evokes depth perception

c. in normal person, the value is about 60 seconds of arc 
   or better

d. amblyopia is unlikely if the stereoacuity is better than 250
    seconds of arc

e. the TNO test can give stereoacuity from 450 to 15 
    degrees of arc

15. The following refers to the amount of light arriving at a given point:

a. illuminance

b. brightness

c. shininess

d. irradiance

e. radiance

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