Design of customized freeform progressive addition lens based on localized precision optimization

The rigid zonal design and inadequate precision control in primary visual zones are the current problems of progressive addition lenses (PALs). To address these limitations, this paper proposed a customized PAL design method with localized precision optimization. The approach systematically defined the objective function for optimization through customizable surface parameters while incorporating precise constraints on optical power and astigmatism in primary visual zones, and ultimately derived optimal surface data via optimization algorithms. To validate the design feasibility, two sets of PALs parameters were customized in this study. The results show that both PALs achieve accurate optical power and astigmatism distributions within specified zones. Notably, the optical power deviations between actual and theoretical values remain within ±0.06D around distance and near reference points, with astigmatism controlled below 0.12D in corresponding zones, thereby achieving localized precision control. This method integrates customized zonal distribution with localized accuracy in optical power and astigmatism, providing a design idea for future customized PALs.