in partial fulfil]ment of the - MSpace - University of Manitoba

were identified. Errors were reflected in the total amount of time
taken to complete the test.
In the 1O-second, the light was dimmed 0.087 u Watt and the subject
had to pick out a white disc from a random pile of 1 white,4 blue and 4
red discs. Four red and 4 blue discs $rere included so that the white
disc was not identified by chance alone. In the 10-second Test, the
light sources for light adaptation and the light adaptation period were
the same as in Thornton's Test. However, the'10-Second Test was different
fron Thornton's Test in test light illuminance and test object. In
the 10-Second Test, the test light was dimmed to 0.087 u Watts and the
subject had to pick out a white disc from a pile of 1 white, 4 blue and
4 red discs. The white, blue and red discs used in the 10-Second Test
were the sane as those used in Thornton's RDAT. The purpose of usíng a
white disc as the test object in the 10-Second Test was to simplify
Thornton's Test procedure and shorten the dark adaptation test time. In
Thornton's Test, the subject had to sort 5 white, 6 blue and 7 red discs
and sort them according to their respective colors. The time taken to
sort white discs rvas much shorter Q5 to 35 seconds) than the time for
sorting the blue discs frorn the red, 150 Lo'180 seconds (Thornton,
80
1977) "
9.3"2 Experiment II
Five graduate students in the Faculty of Human Ecology participated
in experiment iI. All of the five subjects were females between the
ages of 25 and 28. All subjects reported no history of eye disease or
problems related to vision, Subjects were also screened for evidence of
colour-bl indness.