Gaze Duration - LCT Eyegaze Edge User Manual

In this mode, when you look at a key, a small red dot will appear at the location of your eye gaze. When
it is at gaze point, the locator dot may be thought of as a visual cursor that you move around with your
eyes. Generally, there is some slight variation between where a user is looking and where the Eyegaze
Edge predicts that he is looking. If your calibration was accurate to 1/4-inch or better, the system's
prediction should put the locator dot within the desired key.
The purpose of displaying the locator dot at your gaze point is to a) provide feedback that the Eyegaze
Edge knows you are looking at a key, and b) allow you to make corrections, such as moving back into
clear camera focus. Do not look directly at the dot or you will "push" it off the screen!
Dot in Key Center
In this mode, the Eyegaze Edge will place the cursor in the center of the key you are looking at. While
some users prefer this, you lose the feedback that enables you to correct the key selection if the
predicted key is not your intended choice. While Dot in enables you to feel as if you are just moving the
dot around with your eyes, similar to a manual mouse, Dot in Key Center does not provide
instantaneous feedback to facilitate correction.
Key Flashes
When you leave your gaze within a key long enough to trigger it, the Eyegaze Edge responds not only
by taking the action indicated by the key but also by briefly flashing the key and making a clicking
sound.
1.5.2 Eye World/Grid user feedback
In Grid programs there are several options for user feedback, but not all of them are ideal when using
your eyes. Your system will arrive set with a reasonable choice. Follow instructions in the Grid to
change user feedback.

1.5.3 Gaze Duration

The length of time that a user must leave his gaze within a key in order to trigger it is called the gaze
duration. Typical gaze duration values range between 1/4-second and 2/3-second. As you become a
more competent Eyegaze user, you may wish to reduce the gaze duration so that the system responds
more quickly. A shorter gaze duration, which increases the speed, may be particularly desirable when
typing. Within all the Eyegaze keyboard programs, you may temporarily change the gaze duration by
entering the Keyboard Control screen and visually pressing the gaze duration "UP" or "DOWN" keys.
The gaze duration will return to the system setting upon exiting the program.
An assistant can temporarily change the gaze duration in any Eyegaze program by pressing "Decrease
Gaze Duration" key (F6) or "Increase Gaze Duration" key (F7) on the manual keyboard. F6 decreases
(makes it faster) and F7 increases (makes it slower) the gaze duration in 1/10-second increments.
When changing the gaze duration, a message appears in the upper right corner of the screen showing
the new value for the gaze duration. Again, the gaze duration will return to the system setting upon
exiting whatever program the user is in. The default gaze duration may be permanently changed in the
ECS Settings program. For instructions on setting the system gaze duration, see Section 6.1 "Setting
Gaze Control Parameters."
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