The OPD-Scan III machine has been absolutely invaluable to my practice. I perform it on every single one of my cataract patients at their pre-op visit. The information that it gives me is crucial when trying to determine the correct lens choice for the patient. Obviously, the corneal topographer is very helpful in assessing the level of astigmatism and helping guide my patients to a Toric lens implant, if needed. Also, the assessment of higher order aberrations in the cornea is very valuable when determining whether or not my patients are candidates for Multi-focal lens implants. The angle kappa and angle alpha measurements are also very important when determining whether to implant a Toric or Multi-focal lens. It is also helpful to look at the internal OPD map to make sure that everything makes sense with regards to the astigmatism axis and magnitude. I have become so dependent on the machine in my pre-op evaluation that I feel lost if I am unable to obtain a measurement (which hardly ever happens.)