Capabilities and limitations of the Apple Vision Pro as a portable psychophysics tool: Replicating crowding and polar angle asymmetries.

Many classic questions in vision science require presenting stimuli at precisely controlled locations in the visual field, a demand that has traditionally been met with specialized laboratory setups involving chinrests, high-resolution displays, and commercial eye trackers. Recent advances in portable mixed-reality hardware raise the possibility that some forms of visual psychophysics could be conducted on consumer devices outside these fixed laboratory environments. Here, we evaluate one such instrument, the Apple Vision Pro, by asking whether it can support psychophysical experiments on two well-studied aspects of peripheral vision: crowding and polar angle asymmetries. These phenomena provide useful benchmarks because both depend on precise control over stimulus position and their behavioral signatures have been well characterized. At the same time, the Apple Vision Pro poses important methodological challenges for vision research, including the inability to access continuous real-time eye-position data and the use of visionOS "points," rather than degrees of visual angle to specify stimulus size and location. We outline strategies for working within these constraints and argue that the usefulness of the platform is not all-or-none, but depends on the scientific question being asked. Specifically, the Apple Vision Pro may be well suited to paradigms in which fixation can be verified at trial onset, stimulus presentation is brief enough to preclude eye movements, and relative positioning of stimuli is sufficient for the comparison of interest, while remaining less suitable for paradigms requiring continuous gaze monitoring, precise specification of absolute eccentricity, or direct quantitative comparison with conventional lab-based setups.