Reading addition analysis of progressive addition lenses

The optico-physical characteristics of four different designs of progressive addition lenses(PALs) were assessed using a computer-controlled automated focimeter. For each design and for the four designs taken together, reading addition power was shown to correlate positively with PAL progression corridor length and negatively with PAL progression corridor width. Empirical measurements from the four PALs measured showed each design to have more favourable characteristics when compared with a theoretical single power law model.