The OPD-Scan III is a great way to check your surgical technique post-operatively and one of the most common post op problems, whether its LASIK or PRK, is dry eye. You can show a patient, on the OPD, that they are perfectly centered, no prescription but you see all these little speckles? That means your eye is bone dry and it is ruining your optics. You can also subtract out corneal aberrations from the whole eye aberrations so you can find out if there is an early cataract that is going to make a 50 year old patient unhappy after a LASIK procedure. The OPD is such an invaluable tool – being able to sort that out; it educates me and it educates the patient and that maybe we should be talking about a refractive lens exchange instead.