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 Golem's Eye political and morally complex version of "Harry Potter". The book takes its name from the cyclops-like eye of the golem, a magical artefact that, along with an animating parchment, activates the golem. Like the rest of the "Bartimaeus Trilogy", "The Golem's Eye" is set in somewhat modern-day London in an alternate history in which magic is commonplace and magicians are an accepted part of society; in fact, most magicians are in positions of power. They comprise the government, and commoners are treated as inferior. The main character is Nathaniel, a magician who works for the government in the Ministry of