VIS PERC UPDATED ACTUAL Exam Questions and CORRECT Answers
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VIS PERC
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VIS PERC
VIS PERC UPDATED ACTUAL Exam
Questions and CORRECT Answers
What percentage of the eye's refractive power is provided by the cornea? - CORRECT
ANSWER- 67%
The nonphotosensitive pigment that coveres the surface of the macula lutea may protect this
tissue by absorbing - CORRECT ANSWER- blue li...
VIS PERC UPDATED ACTUAL Exam
Questions and CORRECT Answers
What percentage of the eye's refractive power is provided by the cornea? - CORRECT
ANSWER- ✔✔67%
The nonphotosensitive pigment that coveres the surface of the macula lutea may protect this
tissue by absorbing - CORRECT ANSWER- ✔✔blue light
The thickness of the retina is - CORRECT ANSWER- ✔✔0.20 mm
Excessive exposure to UVC is most often associated with inflammation of the - CORRECT
ANSWER- ✔✔cornea
A rod monochromat views the following four patches of monochromatic light: 440 nm, 510
n, 555 nm, and 565 nm. Each patch produces 20 quantal absorptions. Which is brightest? -
CORRECT ANSWER- ✔✔510 nm
Threshold contrast, under photopic conditions, is closest to - CORRECT ANSWER-
✔✔0.010
To optimize the rod-cone break of the dark adaptation curve for clinical testing, the stimulus
should be - CORRECT ANSWER- ✔✔5.0 degree diameter and green
Consider the region of the light adaptation curve that follows Weber's law. As the background
intensity decreases, contrast sensitivity - CORRECT ANSWER- ✔✔remains constant
Assume that the absorption of 10 quanta of 50 nm by the eye of a rod chromomat results in
vision. If the wavelength was 450 nm, how many quanta would need to be absorbed to
produce vision? - CORRECT ANSWER- ✔✔10 quanta
One patient has a pupil diameter of 8 mm and another has a pupil diameter of 4mm. How
much more light reaches the retina of the eye with the larger pupil (compared to the eye with
the smaller)? - CORRECT ANSWER- ✔✔4x
, Appropriate units for luminous power, illuminancec, and luminance are, respectively -
CORRECT ANSWER- ✔✔lumens, foot-candles, foot-lamberts
You are asked to measure the lighting conditions in a classroom to determine if they are
adequate. The lighting conditions should be specified in which units? - CORRECT
ANSWER- ✔✔lumens/m^2
When measured at an angle of 30 degrees to its surface, a matte surface with a reflectance
factor of 0.70 has a luminance of 50 foot-lamberts. What is the luminance when measured
perpendicular to the surface? - CORRECT ANSWER- ✔✔50 foot-lamberts
A subject views two patches of light. One patch consists of an additive mixture of 475 and
510 nm, and the other patch consists of an additive mixture of 490 and 520 nm. By adjusting
the intensities of each of the wavelengths that constitute these patches, the subject is able to
perfectly match the two patches. The subject's vision is - CORRECT ANSWER- ✔✔could be
monochromatic, dichromatic, or trichromatic
An isoluminant grating used in a clinical test consists of red and green bars. Compared to the
red bars, the green bars have - CORRECT ANSWER- ✔✔less radiance
A sample has chromaticity coordinates of y = 0.6 and z = 0.1, What is the dominant
wavelength of this sample? - CORRECT ANSWER- ✔✔520 nm
A yellow background is used when performing short-wavelength automated perimetry
because this background - CORRECT ANSWER- ✔✔suppresses the M- and L-cones
According to Kollner's rule, age-related macular degeneration is most likely to result in
which type of color vision defect? - CORRECT ANSWER- ✔✔tritan
A patient with deuteranomalous trichomacy adjusts the Nagel anomaloscope so that the
mixture and test fields match each other. He subsequently stares at a large green light and
then views the original match. He will report that - CORRECT ANSWER- ✔✔the two fields
remain perfectly matched to each other
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