Visual Processing and Visual Fields
The FieldTester User Interface
Running the FieldTester Applet
References, Links, and Credits
How the Visual Field Tester Works
The FieldTester tries to take into account the complexity of
visual processing and the ability of brain trauma victims to
understand unfamiliar software programs.
The FieldTester starts by presenting a panel of choices. You
can pick the type of test, the number of test items, and
several options that customize the test. You can make your
selections before the test starts, or stop the test and change
the settings at any time.
The selection panel shows five exercise types, each emphasizing a
different part of
the visual processing
- Words. Each item in a word test is paired with a similar
word with letters missing on the left or right side or in
- Lines. Each item in a line test is a straight line. Each
line has a slightly different slope.
- Edges. Each item in an edge test shows the intersection
of two lines.
- Shapes. Five simple shapes are presented, both in outline
and solid form.
- Colors. Each item in a color test presents a circle filled
with a solid color. The colors are chosen at random from a palette
of 256 non-dithering colors.
Beneath the type selection, you can set the total number of
test items for the FieldTester to present. The FieldTester will
distribute the test items evenly across the selected types, but the
order they are presented in will be random.
You can choose which field is tested, which visual
quadrants are tested, and whether the test image stays on the
The FieldTester can test either your left visual field or your
right visual field. Which side gets tested
is up to you. There are four choices:
- Left and Right. The FieldTester alternates questions about
the left field with questions about the right field.
- Left Only. The FieldTester asks you only about the left field.
- Right Only. The FieldTester asks you only about the right field.
- Random. Which field the FieldTester asks you about is
chosen at random.
If you choose Randomize screen locations, the FieldTester will
present the items to all six
visual field quadrants.
If you choose Flash mode, the images stay on the screen
for two seconds before the FieldTester asks you to identify
them. Otherwise, they are always visible.