We want the IOL optic and the capsulorhexis to both be centered. This is especially important for multifocal IOLs and EDOF IOLs which rely on excellent centering for best visual performance. Even with a monofocal IOL, we want the IOL to be centered and the capsulorhexis to overlap the optic for 360 degrees if possible. If the optic edge comes above the capsulorhexis edge for a quadrant, it will cause optic tilt and that can induce aberrations like astigmatism and more. Remember that your signature that you leave on every eye consists of the incision, the capsulorhexis, and even the IOL positioning. Even 10 years in the future, an ophthalmologist will look at the eye and see these three elements of the work that you performed.
click to learn about IOL and capsulorhexis centering: