As surgeons, we know that the refractive outcome for each patient depends on our surgical technique, the calculations, the technology, and the all-important surgical judgment. But it also depends on the patient’s tissue, anatomy, biometry, and healing response. Putting the same lens implant in different eyes (even accounting for the IOL power differences) will produce somewhat different outcomes. One of the more important variables in the outcome of extended depth of focus intra-ocular lens implants (EDOF IOLs) is the patient’s pupil size. We know that in any eye with any lens (be it a natural human lens or an IOL) the pupil size changes the amount of light entering the eye and also the depth of focus. This is similar to cameras where the aperture size (F stop) changes the depth of field and the low light performance for photography. In this video, we explore the ways that pupil size affects the EDOF IOL outcomes, particularly with the Alcon Vivity lens implant (both the Alcon AcrySof Vivity and now the newer Alcon Clareon Vivity, in toric and non-toric varieties). I also give you my best pearls for refractive targeting and IOL calculations.