In Smethers v. Campion, 210 Ariz. 167, 108 P.3d 946 (App. 2005), a laser eye surgeon was sued for malpractice when he failed to re-measure his patient's eyes prior to laser vision surgery. Id. at 169,5. The patient, who wore contact lenses, was advised to remove them for several days prior to surgery, presumptively changing the shape of his eye from the measurement performed during his surgical consultation. Id. Because the measurements relied upon were incorrect, the vision surgery was ineffective and the patient's vision became worse. Id. at6. The defendant retained another laser eye surgeon to testify as a standard of care expert. Id. at 170,9. In his deposition, the expert stated that it was his personal practice to re-measure his patient's eyes prior to performing laser vision surgery even though, in his view, the standard of care did not require the measurement. Id. Prior to trial, the court granted a motion in limine preventing the patient from questioning the expert as to his personal practice, stating that such testimony was not relevant to the jury's determination of the standard of care. Id. at 173,22. The Court disagreed and held that an expert's testimony as to his or her personal practices may be relevant because such evidence is helpful to the jury for determining the applicable standard of care. Id. at 177,32. "How a testifying expert approaches a medical problem may be relevant and of assistance to the jury in determining what the standard of care requires in a similar circumstance." Id. The Court also noted that such evidence is crucial to allow the jury to "fully evaluate the credibility of the testifying expert." Id. It explained that "the fact that an expert testifies that the standard of care does not require what that expert personally does in a similar situation may be a critical piece of information for the jury's consideration." Id. As a result, the trial court's exclusion of the expert's personal ophthalmological practice was error. Further, the error was not merely harmless because there was no way to "predict how a jury would have reacted to" knowledge of the expert's personal practices. Id. at34. Accordingly, the Court reversed the verdict and remanded the case for a new trial. Id.