Different Eye Movement Behaviors Related to Artificial Visual Field Defects–A Pilot Study of Video-Based Perimetry

Visual field defects (VFDs) can be caused by numerous diseases, some of which (e.g., glaucoma) are the main causes of blindness in humans. The present perimetry, which is defined as the measurement of visual field function, has high requirements for patients such as long-term fixation and reliable interaction with the system. In this pilot study, we combined the videos and eye-tracking techniques in a free-watching task and explored the different eye movement behaviors of people with several types of artificial VFDs, such as hemianopia, altitudinal VFDs, and tunnel vision. We carried out the task in a gaze-contingent modality where 38 participants with normal vision were recruited to watch a group of videos monocularly. The eye gaze data were recorded by the tracker during the task. We hypothesized that people with simulated VFDs will produce a more active eye movement coping mechanism to compensate for their visual field disadvantage. A new measurement called eye movement amount (MA) was proposed to describe the amount of eye movement toward a specific direction. Statistically significant differences caused by artificial VFDs were observed by comparing the MA values between the VFD groups and the control group. In addition, we found artificial hemianopia and inferior VFDs lead participants to produced increased MA in the horizontal and vertical directions respectively. Artificial tunnel vision, on the contrary, induces a decreased MAs in both horizontal and vertical directions. The proposed metrics can be used as potential biomarkers for distinguishing VFDs in a free-watching task.