Ppmv Final

Front 1

What percentage of the eye’s refractive power is provided by
the cornea?

Back 1

67%

Front 2

The nonphotosensitive pigment that covers the surface of the macula lutea
may protect this tissue by absorbing ___?

Back 2

blue light

Front 3

The thickness of the retina is about ___?

Back 3

0.20 mm

Front 4

Excessive exposure to UVC, as may occur when snow skiing, is most often
associated with inflammation of the ___?

Back 4

cornea

Front 5

A rod monochromat views the following four patches of monochromatic
light: 440 nm, 510 nm, 555 nm, and 565 nm. Each patch produces 20 quantal
absorptions. Which is brightest?

Back 5

they are all equal

Front 6

Threshold contrast, under photopic conditions, is closest to ___?

Back 6

0.010

Front 7

To optimize the rod–cone break of the dark adaptation curve for clinical test-
ing, the stimulus should be ___?

Back 7

5.0 degrees in diameter and green

Front 8

Consider the region of the light adaptation curve that follows Weber’s law. As
the background intensity decreases, contrast sensitivity ___?

Back 8

remains constant

Front 9

Assume that the absorption of 10 quanta of 510 nm by the eye of a rod
monochromat results in vision. If the wavelength was 450 nm, how many
quanta would need to be absorbed to produce vision?

Back 9

10 quanta

Front 10

One patient has a pupil diameter of 8 mm and another has a pupil diameter
of 4 mm. How much more light reaches the retina of the eye with the largerpupil (compared to the eye with the smaller pupil)?

Back 10

4X

Front 11

Appropriate units for luminous power, illuminance, and luminance are,
respectively ___.

Back 11

lumens, foot-candles, foot-lamberts

Front 12

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 of
the following units?

Back 12

lumens/m2

Front 13

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?

Back 13

50 foot-lamberts

Front 14

A subject views two patches of light. One patch consists of an additive mix-
ture 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
___.

Back 14

could be either monochromatic, dichromatic, or trichromatic

Front 15

The cone photopigment that evolved most recently is probably ___.

Back 15

chlorolabe

Front 16

An isoluminant grating used in a clinical test consists of red and green bars.
Compared to the red bars, the green bars have ___.

Back 16

less radiance

Front 17

Which of the following is not a perceptual attribute of color?

Back 17

colormetric purity

Front 18

The colorimetric purity of a monochromatic patch of 440 nm is closest to ___.

Back 18

1.00

Front 19

The following five pairs of wavelengths are viewed by a person with trichro-
matic vision. Which pair contains wavelengths that appear most similar to
each other?

Back 19

640 nm, 645 nm

Front 20

A sample has chromaticity coordinates of y

Back 20

550