Eye tracking white sclera (limbus tracking). It presents another challenge for vertical eye movements due to obstruction of eyelids. Eye-tracking setups vary greatly: some are head-mounted, some require the head to be stable (for example, with a chin rest), and some function remotely and automatically track the head during motion. Most use a sampling rate of at least 30 Hz. Although 50/60 Hz is more common, today many video-based eye trackers run at 240, 350 or even 1000/1250 Hz, speeds needed in order to capture fixational eye movements or correctly measure saccade dynamics. Eye movements are typically divided into fixations and saccades
The Mind's Eye & Mission of the Viyrans audio dramas "Urgent Calls", "Urban Myths" and "The Vanity Box". This story marks the first appearance of the Viyrans for Big Finish. They first appeared in the short story "No One Died", also written by Nicholas Briggs, featuring the Tenth Doctor and published in the 2007 Doctor Who Storybook. The Viyrans return against the Sixth Doctor in "Patient Zero". The Mind's Eye & Mission of the Viyrans The Mind's Eye is a Big Finish Productions audio drama based on the long-running British science fiction television series "Doctor Who". It is a three-part story written by Colin Brake and was released