Individual differences in the perception of visual illusions are stable across eyes, time, and measurement methods

Vision scientists have tried to classify illusions for more than a century. For example, some studies suggested that there is unique common factor all visual illusions. Other proposed are several subclasses of illusions, such as linear extent or distortions. We previously observed strong within-illusion correlations but only weak between-illusion correlations, arguing in favor an even higher multifactorial space with—more less—each illusion making up its own factor. These mixed results surprising. Here, we examined what individual differences the perception stable across eyes, time, and measurement methods. First, did not find any significant magnitudes seven tested with monocular binocular viewing conditions. In addition, were significantly predicted by acuity. Second, over time. Last, compared two measurements, namely adjustment procedure method constant stimuli, which both led similar differences. Hence, it unlikely arise from instability