The frame has {HEAD ~ a shallow rabbet} which extends from the nasal region of one eye rim, through {TAIL ~ the nasal region} of the bridge, into the nasal region of the other eye rim, and has a predetermined depth 
extends through
The frame has { HEAD ~ a shallow rabbet } which extends from the nasal region of one eye rim , through { TAIL ~ the nasal region } of the bridge , into the nasal region of the other eye rim , and has a predetermined depth
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH