Rehabilitating a patient with bitemporal hemianopia

For those with large field defects, employing totally reflecting mirrors or prisms to reflect information from non-seen areas also blocks out areas within the remaining functional field. A patient with large field defects commonly resists further encroachment upon any part of his limited field. Employing a 30 percent reflectance mirror retains the remaining field unencumbered (because this type of mirror is also semi-transparent) and provides information from the blind area by reflection.