Abstract: We have developed a measure of transient changes in the useful field of view (UFOV) in simulators using gaze-contingent displays (GCDs). It can be used to evaluate safety-critical tasks such as driving or flight, and in training to increase the UFOV under cognitive load, stress, and fatigue. Unlike the established UFOV© measure, our measure can be used in simulators. Furthermore, previous peripheral detection tasks used in simulators controlled neither the target's retinal eccentricity nor stimulus intensity. Our approach overcomes these limitations by using GCDs to present stimuli producing equal performance across eccentricities under single-task conditions for two dependent measures: blur detection and Gabor orientation discrimination. We then measure attention under dual task conditions by varying cognitive load via an N-back task. Our results showed blur sensitivity varied predictably with retinal eccentricity, but detection of blur did not vary with cognitive load. Conversely, peripheral Gabor orientation discrimination showed a significant cognitive load decrement. While this method is still in development, the results suggest that a GC UFOV method is promising.