Of all the technologies that I utilize for preoperative evaluation of my cataract patients, I believe the OPD-Scan III is one of the most important. I depend on the OPD III to evaluate the astigmatism, aberration, and topography of the cornea. It is also extremely useful to check the toric IOL placement after surgery if rotation is suspected. I use the OPD III on every single one of my preoperative patients.