Prentke Romich Company
http://www.prentrom.com/support/article/1754
Tracking Settings (found under Customize Eyegaze Settings Menu)
These settings help to adjust the speed and smoothness of your pointer/cursor movements.
If you have set up your eyegaze system and you aren’t satisfied with the smoothness of your pointer movements, try changing the settings in this option.
Samples to Average
When you select a number in this option, your eyegaze system will continually average the last X number of eye movement signals it receives. This helps to refine pointer movements.
If your pointer/cursor is very jumpy, increase this option. The higher you increase this number, the smoother (but slower) your pointer movement.
Acceleration
If your cursor movement is smooth but too slow for you, increase this option.
Acceleration to Threshold
If your acceleration is set to a speed that is good for you but you find it difficult to lock onto a key to select it, set a threshold for your cursor speed. This will tell the system to use your acceleration speed up to a certain point (the threshold) and then to turn it off until you select the key you want. When your cursor hits the acceleration threshold, it will begin to move more slowly until it locks onto and selects your target key.
Tip! We suggest you try these options using the defaults first. If those are not satisfactory, you will have to use trial and error to find the best results for you.
NOTE: Neither Acceleration nor Acceleration to Threshold are effective unless you have selected a number in the Samples to Average option.