The Effect of Degraded Eye Tracking Accuracy on Interactions in VR

Gaze-based user interfaces and interactions are becoming more prevalent in augmented and virtual reality (AR/VR). The effectiveness of eye tracking for interaction depends on its quality. Many studies discuss eye tracking as an input and interaction modality but do not provide details about eye tracking quality, making it difficult to compare findings. Here we implement a framework to degrade accuracy error with the user in the loop. We then approximate calibration error, with those degradations applied in each block to provide an "Effective Gaze Error." Participants selected single targets (3° or 5° diameter) using an eye tracking sampling frequency and display rate of 120 Hz. Higher "Effective Gaze Error" on smaller targets resulted in decreased human performance and subjective evaluations. Our experiment framework and results provide a starting point for future studies assessing how gaze accuracy degradation impacts performance, beyond interactions tasks.