Gaze-based text spellers have proved useful for people with severe motor diseases, but lack acceptance in general human-computer interaction.In order to use gaze spellers for public displays, they need to be robust and provide an intuitive interaction concept.However, traditional dwell- and blink-based systems need accurate calibration which contradicts fast and intuitive interaction.We developed the first gaze speller explicitly 9.5-4 igora vibrance utilizing smooth pursuit eye movements and their particular characteristics.The speller achieves sufficient accuracy with a one-point calibration and does not require extensive training.
Its interface consists of character elements which move apart from each other in two stages.As each element has a unique track, gaze following this track can be detected by an fig leaf apron algorithm that does not rely on the exact gaze coordinates and compensates latency-based artefacts.In a user study, 24 participants tested four speed-levels of moving elements to determine an optimal interaction speed.At 300 px/s users showed highest overall performance of 3.34 WPM (without training).
Subjective ratings support the finding that this pace is superior.