These goggles have been used routinely over years for visual pathway monitoring during pituitary tumor resection. Nevertheless there is a question if the application of tegaderm affects VEP monitoring. By measuring visual evoked potentials before and after tegaderm placement, we hope to determine if there is a change in evoked potential data due to placement of tegaderm. On other words, we will be able to identify if tegaderm placement affects visual evoked potential data reliability.