In eye typing systems, a dwell time that adjusts to the user’s natural typing speed is highly desirable. We present an algorithm for on-line adjustment of dwell time developed after detailed analysis of exit time upon selection of virtual keys. Exit time was measured using a wide range of dwell times for key selection (300-1100 ms). The results suggest that there was considerable variability in exit time among users indicating the need for calibration of the algorithm. The algorithm was evaluated in a user study and proved to be efficient. We also discuss the shortcomings of the current algorithm’s implementation. Keywords Eye movements, eye tracking, text entry, virtual keyboards ACM Classification Keywords H5.2. Information interfaces and presentation (e.g., HCI): User interfaces – input devices and strategies, interaction styles