A Pilot Evaluation of On-Road Detection Performance by Drivers with Hemianopia Using Oblique Peripheral Prisms
Figure 2
Binocular visual field (Goldmann V4e) of a patient with left HH (a) without peripheral prisms, (b) with 40Δ oblique peripheral prisms as fitted for this study with no vertical separation between the expansion areas (9 mm interprism separation and 30° angle of tilt), and (c) with the original horizontal design of 40Δ peripheral prisms for walking [21] (12 mm interprism separation). The oblique design provides about 20° of lateral expansion into central areas of the blind hemifield in the region used when looking through a car windshield (rectangle represents the field of view through a typical car windshield for driving on the right [22]); the horizontal design does not provide expansion within this area. Small black squares are the individual points mapped during the perimetry.
