Chapter 6: Additional Information
Page 96
System. However, the extent that each subject’s
vision improved varied. Three tests were used to
measure subjects’ vision with the Argus II System.
In the first test, called “Square Localization,”
subjects had to touch a white square that
appeared on a black computer screen. On
average, subjects did better on this test with the
Argus II System on versus when the System was
off at each time point. At one year after implant,
15 of 16 subjects tested did better on this test with
their Argus II System on versus with the System
off.
The second test was harder than the first test. In
the second test, called “Direction of Motion,”
subjects watched a computer screen where a
white bar moved across the screen in different
directions. Subjects had to draw on the screen the
direction that they thought the bar was moving. On
average, subjects did better on this test with the
Argus II System on versus off at each time point.
At one year after implant, 10 of 16 subjects did
better on this test with their Argus II System on
versus with the System off.
The third test was the hardest of the three tests. In
the third test, called “Grating Visual Acuity,” black
and white stripes with decreasing width were
shown on a computer screen. The stripes were
drawn in one of four directions, either up and
