Simple Calibration; Maintaining Focus During Calibration - LCT Eyegaze Edge User Manual

1.4.2 Simple Calibration

The Simple calibration is designed for users who have difficulty controlling their eye fixations, have poor
vision, or are young children. If you wish to use the Simple calibration, click on its icon on the desktop.
The calibration screen will display:
There are several differences between the Simple and Standard calibrations. The Simple calibration
moves the icon to 5 locations that are typically larger in size. In addition to fewer locations to look at,
the icon will move to a new location more quickly. This shorter time for the user to fix his gaze can be
useful for users whose are not steady, e.g. someone with nystagmus. Additionally, the accuracy
requirement is more lenient. Because it is typically not as accurate as the Standard calibration, it should
only be used when a user is unable to complete a Standard calibration.
1.4.3 Simple Calibration vs. Standard Calibration
Simple Calibration
5 Point
Larger points
Must fix gaze for 1/4 second on each point
Acceptance within .66 inches (1.45cm)
7 Retakes

1.4.3 Maintaining Focus During Calibration

To obtain good calibration results, it is desirable to keep the eye in good focus during the calibration
procedure. If the user is significantly out of focus during calibration, a circle appears around the
calibration icon to alert the user to move into focus. If the circle is green, move the screen forward
toward the user. If the circle is red, move the screen away from the user. The color code is a little like a
traffic light:
Green Go forward
Red Retreat (back up)
If the eye is out of focus, the calibration procedure waits for a focused image of the eye before
accepting the calibration point and moving on to the next point. Move the screen (not the camera!) until
the eye image is again clear, or ask the user to move his head back into position.
Standard Calibration
9 Points
Smaller points
Must fix gaze for half a second on each point
Acceptance within .25 inches (.63cm)
5 Retakes
7