The Settings > Adjust your Position menu draws on the screen the perimeter of the Visual Field Map and the location of the blind spot. The next picture shows the Visual Field Map perimeter as white points and the approximate location of the blind spot for the right eye as a dark gray square.
After clicking Adjust your Position command VisionField will show along with a graphic similar to the above one, a short notice telling you how to correct your position:
From about a foot away, fixate on the central cross with one eye while covering the other eye, adjusting the distance between your eye and the screen until all perimeter white points are visible in your peripheral vision.
Move slowly and horizontally the screen cursor, from the central cross to the blind spot marked as a gray square. It should disappear when is close to the square. You may even not see the square when you set the proper viewing distance..
Try to determine the correct distance to the monitor and to keep it constant in all tests. If the distance is properly set, the test will show the blind spot. If the blind sport doesn't appear in your tests that means they are invalid.