1. The following are true about the sensitivity of the visual
system:
a. in the dark the peak sensitivity of the eye is around
500nm
b. in the light the peak sensitivity of the eye is around
555nm
c. the cone can not respond to white flickering light of
20 Hz and above
d. a dark-adapted eye is more sensitive to blue-green
light than a light-adapted eye
e. photopic ERG has a larger value than scotopic ERG
2. Purkinje's shift:
a. refers to the transition of retinal sensitivity between
photopic and scotopic vision
b. refers to the shift in the spectral sensitivity of the human
retina toward shorter wavelengths of light
c. accounts for blue colour appearing brighter at dusk
d. accounts for red colour appearing brighter at dawn
e. is absent in rod monochromat
3. In a patient with dense cataract and poor retina view, the
following tests can be used to test the macular
function:
a. relative afferent pupillary defect
b. laser interferometry
c. Haidinger brushes
d. Visual evoked potential
e. pattern ERG
4. The release of acetylcholine is blocked by:
a. hemicholinum
b. venom of black widow spider
c. cocaine
d. botulinum toxins
e. vesamicol
5. The following are true:
a. Kirschman's law: the greatest contrast in colour is
seen when the luminosity differnece is small
b. Emmbert's law: the perceived size of an object varies
in proportion to the distance of the surface on
which it
is projected
c. Hering's law: the contraction of a muscle is
accompanied by simultaneous and proportional
relaxation of the antagonist
d. Troxler's phenomenon: an image in the periphery of the
retina tends to fade or disappear during steady
fixation
of another object
e. Aubert's phenomenon: in the dark, when the head is
tilted slowly while looking at a bright vertical
line, the
line will tilt in the opposite direction