Weight distributions of spherical and cylindrical power deviations for designing freeform progressive addition lenses

We employed two-dimensional convolution processing and spline interpolation methods to process the weight distributions (WDs) of the spherical and cylindrical power deviations, and assess their effect in designing progressive addition lenses (PALs), based on the minimized error function. Eight power deviation and astigmatism WDs were constructed with different convolution processing schemes and transition area widths connecting the high- and low-weight areas, respectively. Correspondingly, eight PALs were designed, simulated, machined, and evaluated by commercial software. The results show that the number of multiple convolution processing changes from 0 to 15, areas of the far and near areas increase by 35.7% and 76.5%, and maximum peripheral astigmatism increases from 0.75 to 1.5 addition power, respectively. When the width of the transition zone changes from 0 mm to 9 mm, the area of the far and near regions increase by 27.2% and 58.2%, respectively, and the maximum peripheral astigmatism increases from the original value of 1 addition power to 1.25 addition power, respectively.