Quickpie: An Interface for Fast and Accurate Eye Gazed based Text Entry
  Pie menus are suggested as powerful tool for eye gaze based text entry among various interfaces developed so far. If pie menus are used with multiple depth layers then multiple saccades are required per selection of item, which is inefficient because it consumes more time. Also dwell time selection method is limited in performance because higher dwell time suffers from inefficiency while lower one from inaccuracy. To overcome problems with multiple depth layers and dwell time, we designed Quickpie, an interface for eye gaze based text entry with only one depth layer of pie menu and selection border as selection method instead of dwell time. We investigated various parameters like number of slices in pie menu, width characters and safe region, enlarged angle of slice and selection methods to achieve better performance. Our experiment results indicates that six number of slices with width of characters area 120 px performs better as compared to other designs. 
Pawan Patidar, Himanshu Raghuvanshi, Sayan Sarcar
cs.HC