In a prospective study, 244 patients who were scheduled to undergo extracapsular cataract extraction with implantation of the intraocular lens (ECCE/IOL) under local anesthesia were examined to evaluate the risk factors for vis a tergo (VAT) at the "open eye". The intraoperative blood pressure was found to be the most important factor for the occurence of VAT. We think that a reversible suprachoroidal effusion syndrome is responsible for this effect. In order to minimize intraoperative complications, we recommend routine monitoring and treatment if the intraoperative blood pressure is too high during cataract surgery with local anesthesia.