The non spherical annular area has {TAIL ~ a progressive reduction} from maximum addition to zero addition, which enables vision from reading to {HEAD ~ intermediate and distance vision} 
The non spherical annular area has { TAIL ~ a progressive reduction } from maximum addition to zero addition , which enables vision from reading to { HEAD ~ intermediate and distance vision }
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD