Improving the performance of multifocal diffractive lens designs by adding a peripheral piston.

Peripheral piston modulation in diffractive multifocal lenses suggests potential improvements in distance vision quality. Five lens designs-bifocal (BF), bifocal with piston (BFP), trifocal (TF), trifocal with piston (TFP), and a commercial refractive (RCN)-were compared using an adaptive optics visual simulator. Optical simulations revealed enhanced optical quality for distant objects with peripheral pistons, without compromising near vision. Visual performance and quality were assessed in eight cycloplegic young subjects. The peripheral piston was associated with trends toward improved high- and low-contrast visual acuity and visual preference scores at distance, suggesting functional and perceptual benefits over non-piston designs.