{TAIL ~ The eye position detector} monitors light reflected from the users eye to identify {HEAD ~ the pupil position} 
{ TAIL ~ The eye position detector } monitors light reflected from the users eye to identify { HEAD ~ the pupil position }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD