Optical Analysis Of Zonal Bifocals Reveals Complex Interaction With Pupil Size

Zonal Bifocals In a detailed analysis of annular designs of zone bifocal lenses, we explore the optical quality and refractive impact of such designs in the presence of ocular aberrations. This Figure shows that when equating the center and surround zonal areas, image quality will be significantly higher when the center zone is well focused (blue) and lower when the annular zone is focused (red) even when each covers 50% of the pupil area. These differences in image quality are due to the effect that zone geometry has on both diffraction and aberrations.