This is the first distance of travel {HEAD ~ the temple} may flex beyond its fully open, unbiased position on {TAIL ~ the eyewear} 
This is the first distance of travel { HEAD ~ the temple } may flex beyond its fully open , unbiased position on { TAIL ~ the eyewear }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL