Before the operation it is necessary to do a complete eye examination that includes an examination on the biomicroscope, determining visual acuity, intraocular pressure check, topography image of the cornea, measurement of corneal thickness and anterior chamber depth, fundus examination, ultrasound of the eye, intraocular lens power calculation for the eventual replacement of lens and others. All the necessary preoperative ophthalmic tests can be done in our clinic. On the day of surgery patient should also have his medical documentation containing blood exam, ECG and some others; all done with his general practitioner as preparation for general anesthesia.